cmd: add --no-skills, --skill, and --skills-dir CLI flags & config (#55)

* cmd: add --no-skills, --skill, and --skills-dir CLI flags

The pkg/kit Options struct already had full backend support for skills
control (NoSkills, Skills []string, SkillsDir) wired into loadSkills()
in pkg/kit/kit.go, but there were no corresponding CLI flags to drive
them. This commit closes that gap.

Changes in cmd/root.go:

- Add three package-level flag variables alongside the existing
  noExtensionsFlag/extensionPaths group:
    noSkillsFlag bool
    skillsPaths  []string
    skillsDir    string

- Register three persistent cobra flags in init():
    --no-skills        disable skill loading (auto-discovery and explicit)
    --skill <path>     load a skill file or directory (repeatable)
    --skills-dir <dir> override the project-local skills directory
                       used for auto-discovery

- Wire all three into the kitOpts struct literal in runNormalMode()
  so they flow directly into kit.New() -> loadSkills().

No changes to pkg/kit or internal/skills -- the backend was already
complete. No viper binding is needed because kit.go reads these fields
directly from opts rather than from viper (unlike NoExtensions which
uses the viper fallback path).

Example usage:
  kit --no-skills "prompt"
  kit --skill ./my-skill.md --skill ./other-skill.md "prompt"
  kit --skills-dir /path/to/skills "prompt"

Co-authored-by: Claude <claude@anthropic.com>

* docs: document --no-skills, --skill, and --skills-dir CLI flags

Add the three new skills CLI flags to all relevant documentation:

- README.md: add Skills section under Global Flags CLI reference
- www/pages/cli/flags.md: add Skills table (mirrors Extensions section pattern)
- www/pages/cli/commands.md: expand the Skills section with usage examples
  and a description of auto-discovery vs explicit loading vs --no-skills

Co-authored-by: Claude <claude@anthropic.com>

* feat: add config file support for skills options

Skills could previously only be controlled via CLI flags or SDK Options
fields. This commit wires all three skills settings into viper so they
can also be set in .kit.yml / .kit.yaml / .kit.json and via KIT_*
environment variables — matching the pattern used by no-extensions,
no-core-tools, and prompt-template.

cmd/root.go:
- Bind --no-skills, --skill, and --skills-dir flags to viper keys
  (no-skills, skill, skills-dir) so config file values flow through.

pkg/kit/kit.go:
- At skill-load time, merge opts fields with viper values:
  - noSkills = opts.NoSkills || v.GetBool("no-skills")
  - skillPaths: opts.Skills if non-empty, else v.GetStringSlice("skill")
  - skillsDir: opts.SkillsDir if non-empty, else v.GetString("skills-dir")
- Build a shallow-copied mergedOpts so loadSkills() picks up the
  resolved values without mutating the original Options struct.

docs:
- README.md: add skills keys to the Basic Configuration YAML example
- www/pages/configuration.md: add no-skills, skill, skills-dir rows to
  the All configuration keys table

Config file example (.kit.yml):
  no-skills: false
  skill:
    - /path/to/skill.md
  skills-dir: /path/to/skills/

Co-authored-by: Claude <claude@anthropic.com>

* config: add skills keys to default .kit.yml template

Add no-skills, skill, and skills-dir as commented-out examples in the
default config file generated by EnsureConfigExists(), alongside the
existing application settings block.

Co-authored-by: Claude <claude@anthropic.com>

* test: add test coverage for skills CLI flags and config keys

Four test locations updated:

pkg/kit/export_test.go:
- Add ConfigStringSliceForTest() helper to expose v.GetStringSlice()
  from the Kit's isolated viper store, needed to assert skill list values.

pkg/kit/kit_test.go (TestNewWithSkillsOptions):
- NoSkills=true: GetSkills() returns empty slice
- SkillsDir=<empty dir>: kit.New() succeeds with zero skills
- Skills=[file]: single explicit skill file is loaded and name parsed correctly

pkg/kit/viper_isolation_test.go:
- TestSkillsViperKeys: no-API-key struct-level checks for NoSkills, Skills,
  and SkillsDir fields on Options
- TestSkillsConfigFileKeys: full kit.New() round-trips via a written .kit.yml
  for each of the three config keys:
    no-skills: true  → GetSkills() returns empty
    skill: [path]    → named skill loaded from config file path
    skills-dir: dir  → custom discovery root accepted without error

internal/config/config_test.go (TestEnsureConfigExists):
- Assert generated ~/.kit.yml template contains '# Skills configuration',
  'no-skills:', and 'skills-dir:' comment blocks.

Co-authored-by: Claude <claude@anthropic.com>

---------

Co-authored-by: Claude <claude@anthropic.com>

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,79 @@
+name: Bug Report
+description: Report a bug or issue with Kit
+title: "fix: "
+labels: ["bug"]
+body:
+  - type: textarea
+    id: description
+    attributes:
+      label: Bug Description
+      description: What happened? What did you expect to happen?
+      placeholder: |
+        The BorderColor field in ToolRenderConfig is documented but never applied 
+        during tool rendering. I expected the tool block to render with my custom 
+        color, but it uses the default styling instead.
+    validations:
+      required: true
+
+  - type: textarea
+    id: reproduction
+    attributes:
+      label: Steps to Reproduce
+      description: Provide clear steps to reproduce the issue
+      placeholder: |
+        1. Create an extension with `api.RegisterToolRenderer(ext.ToolRenderConfig{...})`
+        2. Set `BorderColor: "#89b4fa"` in the config
+        3. Run a tool that uses this renderer
+        4. Observe the border color is not applied
+      render: markdown
+    validations:
+      required: true
+
+  - type: textarea
+    id: code
+    attributes:
+      label: Relevant Code / Configuration
+      description: Paste any code, configuration, or error messages
+      placeholder: |
+        ```go
+        api.RegisterToolRenderer(ext.ToolRenderConfig{
+            ToolName:    "bash",
+            DisplayName: "Shell",
+            BorderColor: "#a6e3a1",  // This is ignored!
+            Background:  "#1e1e2e",  // This is ignored!
+        })
+        ```
+      render: go
+
+  - type: input
+    id: component
+    attributes:
+      label: Affected Component
+      description: Which part of Kit is affected?
+      placeholder: e.g., extensions, ui, tool rendering, session management
+
+  - type: input
+    id: version
+    attributes:
+      label: Kit Version
+      description: What version of Kit are you running?
+      placeholder: e.g., v0.1.0, commit hash, or "main"
+
+  - type: textarea
+    id: context
+    attributes:
+      label: Additional Context
+      description: Any other context, proposed fixes, or related issues
+      placeholder: |
+        The issue appears to be in `internal/ui/messages.go:RenderToolMessage()` 
+        which ignores the BorderColor and Background fields from ToolRendererData.
+
+  - type: checkboxes
+    id: terms
+    attributes:
+      label: Checklist
+      options:
+        - label: I've searched existing issues and this hasn't been reported yet
+          required: true
+        - label: I've tested with the latest version of Kit
+          required: false

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,11 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Kit Documentation
+    url: https://github.com/mark3labs/kit/tree/main/www/pages
+    about: Check the documentation before filing an issue
+  - name: Extension Examples
+    url: https://github.com/mark3labs/kit/tree/main/examples/extensions
+    about: See working extension examples for reference
+  - name: Discussions
+    url: https://github.com/mark3labs/kit/discussions
+    about: For questions, ideas, or general discussion

.github/ISSUE_TEMPLATE/documentation.yml

@@ -0,0 +1,40 @@
+name: Documentation Issue
+description: Report missing, incorrect, or unclear documentation
+title: "docs: "
+labels: ["documentation"]
+body:
+  - type: textarea
+    id: description
+    attributes:
+      label: Documentation Issue
+      description: What's wrong or missing in the documentation?
+      placeholder: |
+        The ToolRenderConfig documentation mentions BorderColor and Background fields,
+        but the code doesn't actually use them. The docs should either be updated 
+        to reflect reality, or the bug should be fixed.
+    validations:
+      required: true
+
+  - type: input
+    id: location
+    attributes:
+      label: Documentation Location
+      description: Where is the affected documentation?
+      placeholder: e.g., README.md, examples/extensions/tool-renderer-demo.go, pkg/kit docs
+
+  - type: textarea
+    id: suggestion
+    attributes:
+      label: Suggested Improvement
+      description: How should the documentation be improved?
+      placeholder: |
+        Add a note that BorderColor and Background are not yet implemented, 
+        or fix the bug and document the correct behavior.
+
+  - type: checkboxes
+    id: terms
+    attributes:
+      label: Checklist
+      options:
+        - label: I've checked that this documentation issue still exists in the latest version
+          required: true

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,64 @@
+name: Feature Request
+description: Suggest a new feature or enhancement for Kit
+title: "feat: "
+labels: ["enhancement"]
+body:
+  - type: textarea
+    id: description
+    attributes:
+      label: Feature Description
+      description: What would you like to see added or changed?
+      placeholder: |
+        I'd like to be able to customize the border color of tool result blocks 
+        dynamically based on the tool type or result status.
+    validations:
+      required: true
+
+  - type: textarea
+    id: motivation
+    attributes:
+      label: Motivation / Use Case
+      description: Why is this feature needed? What problem does it solve?
+      placeholder: |
+        When running multiple tools in sequence, it's hard to visually distinguish 
+        between file reads (blue), shell commands (green), and errors (red) 
+        without custom border colors.
+    validations:
+      required: true
+
+  - type: textarea
+    id: proposed
+    attributes:
+      label: Proposed Implementation
+      description: How do you think this should work? (optional)
+      placeholder: |
+        Extend `ToolRenderConfig` to accept a function that receives the tool 
+        result and returns a color based on the content:
+        
+        ```go
+        BorderColorFunc: func(result string, isError bool) string {
+            if isError {
+                return "#f38ba8"
+            }
+            return "#89b4fa"
+        }
+        ```
+      render: go
+
+  - type: checkboxes
+    id: alternatives
+    attributes:
+      label: Alternatives Considered
+      options:
+        - label: I've considered workarounds or alternative approaches
+          required: false
+
+  - type: checkboxes
+    id: terms
+    attributes:
+      label: Checklist
+      options:
+        - label: I've searched existing issues and this hasn't been requested yet
+          required: true
+        - label: This feature aligns with Kit's design philosophy (TUI-first, extension-based)
+          required: false

.gitignore

@@ -3,6 +3,7 @@
 .env
 .kit/*
 !.kit/extensions/
+!.kit/prompts/
 aidocs/
 *.log
 /kit

.kit/extensions/go-edit-lint.go

@@ -1,228 +0,0 @@
-//go:build ignore
-
-package main
-
-import (
-	"context"
-	"encoding/json"
-	"fmt"
-	"os/exec"
-	"path/filepath"
-	"strings"
-	"time"
-
-	"kit/ext"
-)
-
-const (
-	diagnosticsTimeout = 20 * time.Second
-	maxOutputBytes     = 12_000
-)
-
-type toolPathInput struct {
-	Path string `json:"path"`
-}
-
-type lintResult struct {
-	Output string
-	Err    error
-}
-
-func Init(api ext.API) {
-	api.OnSessionStart(func(_ ext.SessionStartEvent, ctx ext.Context) {
-		ctx.Print("go-edit-lint extension loaded - will run gopls and golangci-lint on Go file edits")
-	})
-
-	api.OnToolResult(func(e ext.ToolResultEvent, ctx ext.Context) *ext.ToolResultResult {
-		if e.IsError || !isEditOrWrite(e.ToolName) {
-			return nil
-		}
-
-		absPath, ok := resolveGoFilePath(e.Input, ctx.CWD)
-		if !ok {
-			return nil
-		}
-
-		report := runGoDiagnostics(ctx.CWD, absPath)
-		
-		// Check if there are issues and add explicit prompt for the LLM to react
-		goplsIssues, lintIssues := countIssues(report)
-		hasIssues := goplsIssues > 0 || lintIssues > 0
-		
-		var enhanced string
-		if hasIssues {
-			enhanced = e.Content + "\n\n" + report + "\n\n⚠️ DIAGNOSTICS FOUND: Please review the issues above and fix them before proceeding."
-		} else {
-			enhanced = e.Content + "\n\n" + report
-		}
-
-		// Show TUI message block for diagnostics visibility (only if there are issues)
-		if hasIssues {
-			var msgLines []string
-			msgLines = append(msgLines, fmt.Sprintf("File: %s", filepath.Base(absPath)))
-			if goplsIssues > 0 {
-				msgLines = append(msgLines, fmt.Sprintf("gopls: %d issue(s)", goplsIssues))
-			}
-			if lintIssues > 0 {
-				msgLines = append(msgLines, fmt.Sprintf("golangci-lint: %d issue(s)", lintIssues))
-			}
-			msgLines = append(msgLines, "", "⚠️ Please fix these issues before proceeding.")
-
-			borderColor := "#f9e2af" // yellow
-			if goplsIssues > 0 && lintIssues > 0 {
-				borderColor = "#f38ba8" // red
-			}
-
-			ctx.PrintBlock(ext.PrintBlockOpts{
-				Text:        strings.Join(msgLines, "\n"),
-				BorderColor: borderColor,
-				Subtitle:    "go-edit-lint",
-			})
-		}
-
-		return &ext.ToolResultResult{Content: &enhanced}
-	})
-}
-
-func isEditOrWrite(toolName string) bool {
-	return strings.EqualFold(toolName, "edit") || strings.EqualFold(toolName, "write")
-}
-
-func resolveGoFilePath(inputJSON, cwd string) (string, bool) {
-	var args toolPathInput
-	if err := json.Unmarshal([]byte(inputJSON), &args); err != nil || args.Path == "" {
-		return "", false
-	}
-
-	absPath := args.Path
-	if !filepath.IsAbs(absPath) {
-		absPath = filepath.Join(cwd, absPath)
-	}
-
-	if strings.ToLower(filepath.Ext(absPath)) != ".go" {
-		return "", false
-	}
-
-	return absPath, true
-}
-
-func runGoDiagnostics(cwd, absPath string) string {
-	gopls := runGopls(cwd, absPath)
-	lint := runGolangCILint(cwd, "./...")
-
-	return fmt.Sprintf(
-		"<go_diagnostics file=%q>\n[gopls]\n%s\n\n[golangci-lint]\n%s\n</go_diagnostics>",
-		filepath.Base(absPath),
-		formatToolResult(gopls, "No diagnostics."),
-		formatToolResult(lint, "No lint issues."),
-	)
-}
-
-func runGopls(cwd, absPath string) lintResult {
-	ctx, cancel := context.WithTimeout(context.Background(), diagnosticsTimeout)
-	defer cancel()
-
-	cmd := exec.CommandContext(ctx, "gopls", "check", absPath)
-	cmd.Dir = cwd
-	out, err := cmd.CombinedOutput()
-
-	if ctx.Err() == context.DeadlineExceeded {
-		return lintResult{Err: fmt.Errorf("timed out after %s", diagnosticsTimeout)}
-	}
-
-	if err != nil {
-		return lintResult{Output: truncate(string(out), maxOutputBytes), Err: fmt.Errorf("failed to run gopls check: %w", err)}
-	}
-
-	return lintResult{Output: truncate(string(out), maxOutputBytes)}
-}
-
-func runGolangCILint(cwd, target string) lintResult {
-	ctx, cancel := context.WithTimeout(context.Background(), diagnosticsTimeout)
-	defer cancel()
-
-	args := []string{
-		"run",
-		target,
-		"--show-stats=false",
-		"--output.text.path", "stdout",
-		"--output.text.colors=false",
-		"--output.text.print-issued-lines=false",
-	}
-	cmd := exec.CommandContext(ctx, "golangci-lint", args...)
-	cmd.Dir = cwd
-	out, err := cmd.CombinedOutput()
-
-	if ctx.Err() == context.DeadlineExceeded {
-		return lintResult{Err: fmt.Errorf("timed out after %s", diagnosticsTimeout)}
-	}
-
-	trimmed := truncate(string(out), maxOutputBytes)
-	if err == nil {
-		return lintResult{Output: trimmed}
-	}
-
-	exitErr, ok := err.(*exec.ExitError)
-	if ok && exitErr.ExitCode() == 1 {
-		return lintResult{Output: trimmed}
-	}
-
-	return lintResult{Output: trimmed, Err: fmt.Errorf("failed to run golangci-lint: %w", err)}
-}
-
-func formatToolResult(res lintResult, emptyFallback string) string {
-	var lines []string
-	if res.Err != nil {
-		lines = append(lines, "ERROR: "+res.Err.Error())
-	}
-	out := strings.TrimSpace(res.Output)
-	if out == "" {
-		if res.Err == nil {
-			lines = append(lines, emptyFallback)
-		}
-	} else {
-		lines = append(lines, out)
-	}
-	if len(lines) == 0 {
-		return emptyFallback
-	}
-	return strings.Join(lines, "\n")
-}
-
-func truncate(s string, max int) string {
-	if len(s) <= max {
-		return s
-	}
-	return s[:max] + "\n... output truncated ..."
-}
-
-func countIssues(report string) (goplsCount, lintCount int) {
-	// Extract gopls section
-	goplsStart := strings.Index(report, "[gopls]")
-	lintStart := strings.Index(report, "[golangci-lint]")
-	endTag := strings.Index(report, "</go_diagnostics>")
-
-	if goplsStart != -1 && lintStart != -1 {
-		goplsSection := report[goplsStart:lintStart]
-		// Count non-empty lines excluding the header and "No diagnostics." message
-		for _, line := range strings.Split(goplsSection, "\n") {
-			line = strings.TrimSpace(line)
-			if line != "" && line != "[gopls]" && line != "No diagnostics." {
-				goplsCount++
-			}
-		}
-	}
-
-	if lintStart != -1 && endTag != -1 {
-		lintSection := report[lintStart:endTag]
-		// Count non-empty lines excluding the header and "No lint issues." message
-		for _, line := range strings.Split(lintSection, "\n") {
-			line = strings.TrimSpace(line)
-			if line != "" && line != "[golangci-lint]" && line != "No lint issues." {
-				lintCount++
-			}
-		}
-	}
-
-	return goplsCount, lintCount
-}

.kit/prompts/acp-smoke-test.md

@@ -0,0 +1,37 @@
+---
+description: Run ACP smoke test against opencode/kimi-k2.5 to verify JSON-RPC stdio works
+---
+
+Run the ACP smoke test to verify the Kit ACP server works correctly over JSON-RPC stdio with streaming responses.
+
+## Steps
+
+1. Build the kit binary:
+   ```bash
+   go build -o output/kit ./cmd/kit
+   ```
+
+2. Run the smoke test Python script against opencode/kimi-k2.5:
+   ```bash
+   python3 scripts/acp_smoke_test.py
+   ```
+
+3. Verify the output shows:
+   - `session/new` returns a valid `sessionId`
+   - `session/prompt` streams `agent_thought_chunk` notifications (reasoning)
+   - `session/prompt` streams `agent_message_chunk` notifications (response)
+   - Final result has `stopReason: "end_turn"`
+   - `✓ SMOKE TEST PASSED` at the end
+
+4. If the test fails, check:
+   - `output/kit` binary exists and is executable
+   - `OPENCODE_API_KEY` or `OPENCODE_ZEN_API_KEY` environment variable is set
+   - `scripts/acp_smoke_test.py` exists
+   - The model `opencode/kimi-k2.5` is available (`kit models opencode | grep kimi-k2.5`)
+
+5. For testing with a different model, edit the script or set the `MODEL` variable:
+   ```bash
+   MODEL=anthropic/claude-sonnet-4-5 python3 scripts/acp_smoke_test.py
+   ```
+
+The smoke test exercises the full ACP protocol: session lifecycle, streaming notifications, and tool-free prompt completion.

.kit/prompts/code-audit.md

@@ -0,0 +1,146 @@
+---
+description: Read-only audit for dead code, duplication, boundary violations, and refactor opportunities
+---
+
+Perform a comprehensive **read-only** audit of this repository and report
+findings. **Do not edit, rename, or delete any files.** Optional focus / scope
+hints from the user: $@
+
+## Scope
+
+If the user supplied focus hints above (a package path, a subsystem name, a
+concern like "TUI" or "extensions"), scope the audit accordingly. Otherwise
+audit the whole repo, prioritising the highest-traffic packages first
+(`cmd/`, `internal/`, `pkg/kit/` for this repo).
+
+## Steps
+
+1. **Map the repo first**:
+   - `ls` / `find` the top-level layout and list every Go package
+   - Read `AGENTS.md`, `README.md`, and any `pkg/*/doc.go` to understand the
+     intended architectural boundaries (SDK vs internal vs TUI vs cmd vs
+     extension surface)
+   - Note the public SDK surface (`pkg/kit/`) and any documented invariants
+     (e.g. "no dependency name leakage", "UI never imports extensions
+     directly") — these define what counts as a violation
+
+2. **Hunt for dead code**:
+   - Run `go vet ./...` and capture warnings
+   - Use `grep` to find exported symbols (`^func [A-Z]`, `^type [A-Z]`,
+     `^var [A-Z]`, `^const [A-Z]`) and cross-reference call sites. Symbols
+     with zero non-test references inside the module are suspects
+   - Check for unreferenced files, `// TODO: remove` markers, commented-out
+     blocks, and `_ = x` discard patterns
+   - If `staticcheck`, `deadcode`, or `unused` are available on PATH, run
+     them and include their output verbatim
+   - **Do not delete anything** — list candidates with file:line and a
+     confidence level (high / medium / low)
+
+3. **Find unnecessary duplication**:
+   - Look for near-identical function bodies, struct shapes, or switch
+     statements across packages — `grep` for repeated function signatures
+     and copy-pasted string literals / error messages is a fast first pass
+   - Distinguish *coincidental* duplication (two things that happen to look
+     alike but evolve independently) from *unnecessary* duplication (same
+     intent, drifting in lockstep) — only flag the latter
+   - For each cluster, propose where the extracted helper should live
+     (which package, which file) and whether it crosses a boundary
+
+4. **Check concerns / boundary violations**:
+   - **SDK leakage**: grep `pkg/kit/` for imports of `internal/...` types
+     in exported signatures, and for dependency-name leakage in exported
+     names / godoc (e.g. library jargon appearing in `LLM*` types)
+   - **UI ↔ extensions**: grep `internal/ui/` for any import of
+     `internal/extensions/` — per AGENTS.md the UI must not import
+     extensions directly; converters in `cmd/root.go` should bridge them
+   - **cmd vs internal**: business logic living in `cmd/` that should be
+     in `internal/` (and vice versa)
+   - **Cyclic risk**: packages that import each other transitively or that
+     reach across sibling boundaries unexpectedly
+   - For each violation, cite the offending import / signature with
+     file:line
+
+5. **Spot refactor opportunities**:
+   - Long functions (>80 lines) doing multiple unrelated things
+   - Deeply nested conditionals that flatten well with early returns
+   - Repeated `if err != nil { return fmt.Errorf("...: %w", err) }` chains
+     that could become helpers — but only where the wrapping context is
+     genuinely uniform
+   - Structs with too many fields that hint at split responsibilities
+   - Exported APIs that would be cleaner with options structs / functional
+     options
+   - Tests that share setup boilerplate ripe for a helper
+   - Flag each with: location, current shape (1-2 lines), proposed shape
+     (1-2 lines), and estimated risk (low / medium / high)
+
+6. **Cross-check against project rules**:
+   - Re-read `AGENTS.md` "Key Patterns" section and verify nothing in your
+     findings contradicts the documented gotchas (Yaegi interface ban,
+     `prog.Send()` from `Update()`, function-field bug, etc.) — if a
+     "refactor" would reintroduce a known pitfall, drop it from the report
+     and note why
+
+7. **Write the report** as your final message (do not write it to disk)
+   structured as:
+
+   ```
+   # Code Audit Report
+
+   ## Summary
+   - N dead-code candidates
+   - N duplication clusters
+   - N boundary violations
+   - N refactor opportunities
+
+   ## Dead Code
+   ### High confidence
+   - path/to/file.go:LINE — symbol — reason
+
+   ### Medium confidence
+   ...
+
+   ## Duplication
+   ### Cluster: <short name>
+   - Sites: file:line, file:line, …
+   - Suggested home: package/path
+   - Notes: …
+
+   ## Boundary Violations
+   - Rule: <which rule from AGENTS.md / project convention>
+   - Offender: file:line
+   - Fix sketch: …
+
+   ## Refactor Opportunities
+   - Location: file:line
+   - Current: …
+   - Proposed: …
+   - Risk: low/medium/high
+   - Why it's worth it: …
+
+   ## Suggested Next Steps
+   1. …
+   2. …
+   ```
+
+8. **End the report with an explicit reminder** that no files were modified,
+   and recommend the user pick the highest-leverage items to act on
+   manually (or via a follow-up `/fix-issue` style prompt) rather than
+   running a sweeping refactor.
+
+## Guidelines
+
+- **Read-only, always**: no `edit`, no `write`, no `git commit`, no `go mod
+  tidy`. Use only `read`, `grep`, `find`, `ls`, and read-only `bash`
+  commands (`go vet`, `go build -o /tmp/...`, `staticcheck`, etc.)
+- **Cite every finding** with `path/to/file.go:LINE` so the user can jump
+  straight to it
+- **Be honest about confidence**: false positives in a code audit are
+  expensive — prefer "medium confidence, worth a look" over confidently
+  wrong claims
+- **Quantity isn't quality**: 10 sharp findings beat 100 nitpicks. Cut
+  anything that's purely stylistic unless it directly causes one of the
+  four issue categories above
+- **Skip generated code** (`*.pb.go`, `*_gen.go`, anything under
+  `vendor/`) and obvious third-party copies
+- **Don't propose architectural rewrites** — stay within the existing
+  shape of the repo and recommend incremental, reviewable changes

.kit/prompts/commit-push.md

@@ -0,0 +1,30 @@
+---
+description: Stage, commit, and push changes with an auto-generated conventional commit message
+---
+
+Review the current git status and diff, then stage all changes, write a concise conventional commit message, commit, and push to the current branch.
+
+## Steps
+
+1. **Check status**: `git status` — understand what has changed
+2. **Review the diff**: `git diff` (and `git diff --cached` if anything is already staged) — read the actual changes
+3. **Stage everything**: `git add -A`
+4. **Craft the commit message** following Conventional Commits:
+   - Format: `<type>(<scope>): <short summary>`
+   - Types: `feat`, `fix`, `refactor`, `chore`, `docs`, `test`, `perf`, `build`
+   - Scope: optional, the subsystem affected (e.g. `ui`, `cmd`, `config`)
+   - Summary: imperative mood, lowercase, no trailing period, ≤72 chars
+   - Body: add a blank line then bullet points for non-trivial changes
+   - Do **not** include "Generated by" or similar noise
+5. **Commit**: `git commit -m "<message>"`
+6. **Push**: `git push`
+
+## Guidelines
+
+- Read the actual diff — do not guess from filenames alone
+- Prefer one well-scoped commit; do not split unless the changes are clearly unrelated
+- Keep the subject line under 72 characters
+- Use the body to explain *what* and *why*, not *how*
+- If there is nothing to commit, say so and stop
+
+$@

.kit/prompts/create-pr.md

@@ -0,0 +1,47 @@
+---
+description: Open a GitHub PR for the current branch using the repo's PR template
+---
+
+Open a GitHub pull request for the current branch, filling out the repository's PR template with a description grounded in the actual commits and diff.
+
+## Steps
+
+1. **Verify the branch is pushed**:
+   - `git status -sb` and `git log @{u}..HEAD --oneline 2>/dev/null` — if there is no upstream or unpushed commits, run `git push -u origin "$(git branch --show-current)"` first
+   - If the working tree is dirty, stop and tell the user to commit first (suggest `/commit-push`)
+2. **Gather context**:
+   - `git log origin/main..HEAD --oneline` — list of commits going into the PR
+   - `git diff origin/main...HEAD --stat` then `git diff origin/main...HEAD` — read the actual changes
+   - Identify the linked issue (from commit messages, branch name, or extra user input: $@) — capture as `Fixes #N` if applicable
+3. **Locate the PR template**:
+   - Check `.github/pull_request_template.md`, `.github/PULL_REQUEST_TEMPLATE.md`, or `docs/pull_request_template.md`
+   - If none exists, use a minimal `## Description` / `## Type of Change` / `## Checklist` structure
+4. **Draft the PR body** by filling out the template:
+   - **Description**: 1–3 short paragraphs explaining *what* changed and *why*, grounded in the diff. Include a brief before/after example for new APIs when useful.
+   - **Fixes #N**: only if there is a real linked issue
+   - **Type of Change**: tick the single most accurate box with `[x]` (leave others as `[ ]`)
+   - **Checklist**: tick items that are genuinely true (style, self-review, tests added, docs updated)
+   - **Additional Information**: bullet list of added / modified files and any backward-compatibility notes
+   - Remove template sections explicitly marked "remove if not applicable" (e.g. MCP Spec Compliance) when they don't apply
+5. **Write the body to a temp file**: `/tmp/pr-body-<branch-or-issue>.md` — never inline a long body via `--body`, always use `--body-file`
+6. **Choose the title**: prefer the subject of the primary commit if it already follows Conventional Commits; otherwise craft one in the same style (`<type>(<scope>): <imperative summary>`, ≤72 chars)
+7. **Create the PR**:
+   ```
+   gh pr create \
+     --title "<title>" \
+     --body-file /tmp/pr-body-<...>.md \
+     --base main \
+     --head "$(git branch --show-current)"
+   ```
+   Use the repo's actual default branch if it isn't `main` (`gh repo view --json defaultBranchRef -q .defaultBranchRef.name`)
+8. **Report the PR URL** returned by `gh` and stop
+
+## Guidelines
+
+- Read the diff and commit messages — do **not** invent features that aren't in the code
+- One PR per logical change; if the branch contains unrelated commits, surface that and ask before continuing
+- Keep the description focused on reviewer-relevant information (what / why), not a replay of the diff
+- Only check checklist boxes that are actually satisfied; leave the rest unchecked rather than lying
+- If `gh` is not authenticated (`gh auth status` fails), stop and tell the user
+
+$@

.kit/prompts/feature-request.md

@@ -0,0 +1,86 @@
+---
+description: Create a feature request using the GitHub template
+---
+
+Create a feature request for the Kit repository. The user wants to request: $@
+
+## Feature Request Template
+
+This prompt uses the `feature_request` GitHub template which requires:
+
+| Field | Required | Purpose |
+|-------|----------|---------|
+| **Feature Description** | Yes | What should be added or changed |
+| **Motivation / Use Case** | Yes | Why is this needed? What problem does it solve? |
+| **Proposed Implementation** | No | How do you think this should work? |
+
+## Steps
+
+1. **Understand the request** from the user input: $@
+   - What capability is missing?
+   - What would the ideal behavior look like?
+
+2. **Ask clarifying questions** if needed:
+   - "What problem does this solve for you?"
+   - "How would you expect this to work?"
+   - "Are there similar features in other tools you use?"
+
+3. **Craft the title** using conventional format:
+   - `feat: <short description>`
+   - Lowercase, imperative mood, ≤72 chars
+   - Good examples:
+     - `feat: add keyboard shortcut for clearing input`
+     - `feat: support custom themes per extension`
+     - `feat: add fuzzy matching to model selector`
+   - Bad examples:
+     - `Feature request: can we have...` (too vague)
+     - `It would be nice if...` (not imperative)
+
+4. **Build the body** with the template fields:
+
+   **Feature Description:**
+   - Clear statement of what to add/change
+   - Be specific about the behavior
+   - Include UI/UX details if relevant
+
+   **Motivation / Use Case:**
+   - What problem does this solve?
+   - Current workaround (if any) and why it's insufficient
+   - Who benefits from this feature?
+
+   **Proposed Implementation** (optional but helpful):
+   - High-level approach
+   - API changes if applicable
+   - Example usage code
+
+5. **Create the issue**:
+   ```bash
+   gh issue create --template feature_request --title "feat: ..." --body "..."
+   ```
+
+6. **Confirm success**:
+   - Show the issue URL and number
+   - Mention it was created with the feature_request template
+
+## Guidelines
+
+- Focus on the *problem* first, then the solution
+- Include concrete examples of how the feature would be used
+- Consider edge cases and mention them
+- If proposing API changes, show before/after code
+- Check if similar features exist in related tools (mention them for reference)
+- Align with Kit's philosophy: TUI-first, extension-based, keyboard-driven
+
+## Example
+
+User: `/feature-request I want to be able to customize tool border colors dynamically`
+
+You:
+1. Title: `feat: dynamic border colors for tool results based on status`
+2. Body:
+   - **Feature Description**: Allow `ToolRenderConfig` to accept a function that determines border color based on tool result content or status, enabling dynamic visual feedback.
+   - **Motivation**: When running multiple tools, it's hard to distinguish file reads (blue), shell commands (green), and errors (red) without custom colors per result.
+   - **Proposed Implementation**: Add `BorderColorFunc` callback that receives `(result string, isError bool)` and returns a color string.
+
+3. Execute: `gh issue create --template feature_request --title "feat: ..." --body "..."`
+4. Confirm: Created issue #43 using feature_request template

.kit/prompts/file-issue.md

@@ -0,0 +1,100 @@
+---
+description: File a GitHub issue using the appropriate template
+---
+
+File a GitHub issue for the Kit repository. The user wants to create an issue about: $@
+
+## Issue Templates Available
+
+This repository has structured issue templates. You MUST use the appropriate template:
+
+| Type | Template | Use For |
+|------|----------|---------|
+| `bug` | `bug_report` | Something is broken, not working as expected |
+| `feat` | `feature_request` | New feature, enhancement, improvement |
+| `docs` | `documentation` | Missing, incorrect, or unclear documentation |
+
+## Steps
+
+1. **Determine the issue type** from the user input: $@
+   - Bug → use `--template bug_report`
+   - Feature → use `--template feature_request`  
+   - Documentation → use `--template documentation`
+
+2. **Ask clarifying questions** if critical info is missing:
+   - For bugs: "What were you doing when this happened?" (reproduction steps)
+   - For features: "What problem does this solve?" (motivation)
+   - For docs: "Where did you look for this information?" (location)
+
+3. **Craft the title** using conventional format:
+   - `<type>: <short description>`
+   - Lowercase, imperative mood, ≤72 chars
+   - Examples:
+     - `fix: ToolRenderConfig BorderColor ignored during rendering`
+     - `feat: add keyboard shortcut for clearing input`
+     - `docs: clarify extension widget lifecycle`
+
+4. **File the issue** using the template:
+   ```bash
+   # For bugs
+   gh issue create --template bug_report --title "fix: ..." --body "..."
+   
+   # For features
+   gh issue create --template feature_request --title "feat: ..." --body "..."
+   
+   # For documentation
+   gh issue create --template documentation --title "docs: ..." --body "..."
+   ```
+
+   The template will guide the user through the required fields. You need to provide:
+   - **Bug reports**: Description, reproduction steps, expected vs actual behavior
+   - **Feature requests**: Description, motivation/use case, optional proposed implementation
+   - **Documentation**: Description, location of docs, suggested improvement
+
+5. **Confirm success** by showing:
+   - The issue URL
+   - The issue number
+   - Which template was used
+
+## Template Field Guide
+
+### Bug Report (`bug_report`)
+Required fields in the body:
+- **Bug Description** - what happened vs expected
+- **Steps to Reproduce** - numbered list to recreate the bug
+- **Relevant Code** - code snippets, configuration, error messages
+- **Component** - which part of Kit (ui, extensions, session, etc.)
+- **Version** - Kit version or commit hash
+
+### Feature Request (`feature_request`)
+Required fields in the body:
+- **Feature Description** - what to add/change
+- **Motivation / Use Case** - why this is needed
+- **Proposed Implementation** - how it could work (optional)
+
+### Documentation (`documentation`)
+Required fields in the body:
+- **Documentation Issue** - what's wrong or missing
+- **Documentation Location** - file or URL where docs exist
+- **Suggested Improvement** - how to fix the docs
+
+## Guidelines
+
+- ALWAYS use `--template <name>` instead of bare `gh issue create`
+- Include file paths and line numbers when you know them
+- Use triple backticks for code blocks
+- Keep the body factual - avoid speculation unless in "Proposed Fix" section
+- If you're unsure about technical details, say so in the issue
+- For UI bugs, describe what you see vs what you expect
+- For API bugs, include the relevant struct/function names
+
+## Example Usage
+
+User: `/file-issue The ToolRenderConfig BorderColor field is documented but never used in rendering`
+
+You: 
+1. Determine this is a **bug** (documented field doesn't work)
+2. Use `--template bug_report`
+3. Gather: reproduction steps (register renderer with BorderColor), expected (custom color), actual (default color)
+4. Create issue with title `fix: ToolRenderConfig BorderColor and Background fields are ignored`
+5. Confirm: Created issue #42 using bug_report template

.kit/prompts/fix-issue.md

@@ -0,0 +1,61 @@
+---
+description: Implement the fix/feature/docs change requested by a GitHub issue
+---
+
+Resolve GitHub issue #$1 by reading it, classifying it, and producing the appropriate code or doc change. **Stop once the working tree contains the change** — committing, pushing, and opening a PR are handled by `/commit-push` and `/create-pr`.
+
+## Steps
+
+1. **Fetch the issue**:
+   - Run: gh issue view $1 --json number,title,body,labels,state,author,comments
+   - If the issue is closed, stop and ask the user whether to proceed
+   - Read the **entire** thread including comments — the latest comment often refines the ask
+
+2. **Classify the issue** from labels, title prefix, and body content:
+   - `bug` / `fix:` → reproduce, then fix
+   - `enhancement` / `feature` / `feat:` → design, then implement
+   - `documentation` / `docs:` → locate and update docs
+   - `question` / `discussion` → answer in a comment, do **not** write code
+   - Anything else → ask the user how to proceed
+
+3. **Create a working branch** off the default branch:
+   - `git checkout main && git pull --ff-only`
+   - Branch name: <type>/$1-<slug> (e.g. `fix/42-borderColor-ignored`, `feat/57-keyboard-clear`, `docs/63-widget-lifecycle`)
+
+4. **Do the work** based on type:
+
+   ### Bug (`bug` label / `fix:` title)
+   - Reproduce the failure first (write a failing test if feasible) — if you cannot reproduce, comment on the issue asking for clarification and stop
+   - Locate the root cause; do not patch symptoms
+   - Add or extend a regression test that fails before and passes after the fix
+   - Run `go test ./... -race` and `golangci-lint run`
+
+   ### Feature (`enhancement` / `feature` label / `feat:` title)
+   - Re-read the motivation and proposed implementation in the issue body
+   - For large, ambiguous, or breaking changes, sketch the design in a comment on the issue and wait for sign-off before writing code
+   - Implement behind sensible defaults; add godoc on every exported symbol
+   - Add unit tests covering the new behaviour and edge cases
+   - Update `README.md` / `docs/` if the public surface changed
+   - Run `go test ./... -race` and `golangci-lint run`
+
+   ### Documentation (`documentation` label / `docs:` title)
+   - Open the file/URL referenced in the issue's "Documentation Location"
+   - Apply the suggested improvement; verify code samples compile (`go build ./...`)
+   - No tests required, but run `golangci-lint run` if Go files were touched
+
+5. **Report**:
+   - Branch name (`git branch --show-current`)
+   - Summary of files changed (`git status -s`) and the diff highlights
+   - Test/lint results (pass/fail with key output)
+   - Suggest the next step explicitly:
+     - `/commit-push` to commit with a Conventional Commit subject (the message should reference `(#$1)` and include `Fixes #$1` so merge auto-closes)
+     - then `/create-pr $1` to open the pull request
+
+## Guidelines
+
+- This prompt **stops at a clean working tree with the change applied** — do not run `git commit`, `git push`, or `gh pr create`
+- If the issue is unclear, post a clarifying comment on the issue and stop; do not guess
+- Keep the change scoped to the issue; surface unrelated cleanups separately
+- For breaking changes or architecture shifts, propose the design on the issue first and wait for maintainer sign-off
+- If the issue is a duplicate or already fixed on `main`, comment with the reference and stop
+- Do not close the issue manually — the eventual PR's `Fixes #$1` handles that on merge

.kit/prompts/new-prompt.md

@@ -0,0 +1,84 @@
+---
+description: Scaffold a new prompt template in .kit/prompts/
+---
+
+Create a new kit prompt template. The user wants a prompt that does: $@
+
+## What a prompt template is
+
+A prompt template is a `.md` file in `.kit/prompts/` (project-local) or `~/.kit/prompts/` (global).
+It becomes a `/slug` slash command in the kit input box — typed as `/filename` with optional arguments.
+
+## File format
+
+```
+---
+description: One-line description shown in autocomplete
+---
+
+Body text of the prompt. Reference user-supplied arguments
+with positional placeholders (see "Argument placeholders" below).
+```
+
+- **Filename** → slug: `commit-push.md` becomes `/commit-push`
+- **Frontmatter**: only `description` is recognised; keep it under ~80 chars
+- **Body**: plain markdown; the full text is submitted as the user's message when the template fires
+- **Required args**: kit infers required positional args from the highest `$N` it finds *outside* backtick/tilde code fences — a stray `$2` in active prose means kit will refuse to run without 2 arguments
+
+## Argument placeholders
+
+kit performs shell-style substitution before sending the prompt to the model:
+
+- `$1`, `$2`, … — positional arguments (1-indexed)
+- `${1}`, `${2}`, … — same, brace form (use when followed by digits/letters: `${1}_suffix`)
+- `$@` — all arguments joined by spaces (zero or more, optional)
+- `$+` — all arguments, **at least one required**
+- `$ARGUMENTS` / `${ARGUMENTS}` — alias for `$@`
+- `${@:N}` — args from the Nth onwards (1-indexed, bash-style)
+- `${@:N:L}` — `L` args starting from the Nth
+
+### ⚠️ Critical: code fences and inline code preserve placeholders verbatim
+
+Anything inside triple-backtick fences, `~~~` fences, or single-backtick `inline` code spans is **left untouched** so example code samples don't get corrupted. That means:
+
+- An inline-coded `gh issue view $1` stays literal `$1` in the model's input ❌
+- The same command without backticks: gh issue view $1 → expands to `gh issue view 42` ✓
+
+**Rule of thumb:** if you want a placeholder to substitute, keep it outside backticks and fences. If you want a literal `$1` in the output (e.g. teaching the user shell syntax), put it inside backticks.
+
+### Workarounds for "I want it to look like code AND substitute"
+
+1. **Drop the backticks** around just the placeholder portion — the rest can still read as a command line in prose
+2. **Use a 4-space-indented code block** instead of a triple-backtick fence — kit only skips backtick/tilde fences, so indentation-style code blocks still get substitution:
+
+       git push -u origin "$(git branch --show-current)"
+       gh pr create --title "fix: ... (#$1)" --base main
+
+3. **Bind once, reference loosely**: put `Issue: $1` at the top in prose, then leave the backticked examples literal — the model will substitute mentally
+
+## Steps
+
+1. **Understand the workflow** the user described in $@ — ask a clarifying question if the intent is ambiguous
+2. **Choose a filename**: short, lowercase, hyphen-separated, descriptive (e.g. `code-review.md`)
+3. **Write the description**: one sentence, imperative, fits in autocomplete
+4. **Decide on arguments**:
+   - No args needed → omit placeholders entirely
+   - One required value (issue number, PR url, file path) → use `$1`
+   - Free-form trailing context → end with a single `$@` line
+   - Multiple distinct values → use `$1`, `$2`, … and document each at the top
+5. **Draft the body**:
+   - Open with a single sentence stating the goal, weaving in `$1`/`$@` where the value belongs
+   - Use `## Steps` for multi-step workflows; use plain prose for simple prompts
+   - Be specific: name commands, flags, and file paths where relevant
+   - **Audit every backtick and code fence**: any `$N` or `$@` inside them will not expand — was that intentional? If not, apply one of the workarounds above
+6. **Write the file** to `.kit/prompts/<slug>.md`
+7. **Verify substitution** by mentally (or actually) replacing `$1`/`$@` with a sample value and confirming every reference resolves — and that the prompt's *own* example snippets don't accidentally bump the required-arg count (wrap illustrative `$N` examples in triple-backtick fences, not 4-space indentation, so `RequiredArgs()` ignores them)
+8. **Confirm** by showing the final file content and the slash command that activates it (e.g. `/code-review 42`)
+
+## Guidelines
+
+- Keep prompts action-oriented — they should tell kit *what to do*, not just *what to think about*
+- Prefer concrete steps over vague instructions
+- A prompt that does one thing well beats one that tries to cover every edge case
+- If the workflow already exists as a prompt, suggest extending it instead of duplicating
+- When in doubt about substitution behaviour, write the file and run `/<slug> testvalue` once to confirm — wrong placement of backticks is the #1 failure mode

.kit/prompts/release-tagger.md

@@ -0,0 +1,70 @@
+---
+description: Semantic version tagging workflow - analyzes commits and tags releases
+---
+
+# Release Tagging Workflow
+
+Tag a new version of this Go project following semantic versioning.
+
+## Steps
+
+1. **Fetch remote tags**: `git fetch --tags origin`
+
+2. **Find latest version**: `git tag -l | sort -V | tail -5` to see recent tags
+
+3. **Analyze changes since last tag**:
+   - `git log <latest-tag>..HEAD --oneline` - list commits
+   - `git diff <latest-tag>..HEAD --stat` - see file stats
+   - `git diff <latest-tag>..HEAD --name-only` - see changed files
+
+4. **Determine version bump** (Semantic Versioning):
+   - **MAJOR (X.0.0)**: Breaking API changes, incompatible modifications
+   - **MINOR (0.X.0)**: New features, backward-compatible additions
+   - **PATCH (0.0.X)**: Bug fixes, backward-compatible fixes
+   
+   Look for indicators:
+   - `feat:` or `feature:` commits → MINOR
+   - `fix:` or `bugfix:` commits → PATCH
+   - `breaking:` or `BREAKING CHANGE:` → MAJOR
+   - Breaking API changes in `pkg/` or public interfaces → MAJOR
+   - New commands, flags, or features → MINOR
+   - Documentation-only changes → PATCH (or skip)
+
+5. **Calculate new version**: Increment appropriate segment, reset lower segments to 0
+
+6. **Draft tag message**:
+   - Summarize key changes from commits
+   - Group by type (Features, Fixes, Breaking Changes)
+   - Keep concise but informative
+
+7. **Create annotated tag**: `git tag -a vX.Y.Z -m "vX.Y.Z - <summary>\n\n<detailed list>"`
+
+8. **Push tag**: `git push origin vX.Y.Z`
+
+## Guidelines
+
+- Always fetch remote tags first to avoid conflicts
+- Use annotated tags (`-a`) with descriptive messages
+- Follow semver strictly - when in doubt, prefer conservative bump (patch over minor)
+- For Go projects, changes to `pkg/` or exported APIs warrant careful version consideration
+- If no changes since last tag, suggest skipping the release
+- Include commit summaries in the tag message body
+
+## Example Tag Message Format
+
+```
+v0.30.1 - Bug fixes for model handling and UI improvements
+
+Fixes:
+- Properly handle think tags from Qwen/DeepSeek models
+- Handle custom provider model persistence and bare model names
+
+Improvements:
+- UI style refactoring and cleanup
+```
+
+Wait for the user to confirm the version and message before executing tag commands.
+
+---
+
+$@

.kit/prompts/update-docs.md

@@ -0,0 +1,52 @@
+---
+description: Audit and update project documentation (README and docs site) for a recent change
+---
+
+Review recent code changes, identify all documentation surfaces that should
+mention them, and update each one — grounded in the actual diff, not guesses.
+
+## Steps
+
+1. **Identify the change**:
+   - If the user input ($@) names a commit / PR / branch / topic, use that as the focus
+   - Otherwise inspect `git log origin/main..HEAD --oneline` and `git diff origin/main...HEAD --stat` to discover what shipped on the current branch
+   - Read the actual diff (`git diff origin/main...HEAD`) — never document features that aren't in the code
+
+2. **Inventory the doc surfaces**:
+   - `README.md` at the repo root
+   - Any docs site (commonly `www/`, `docs/`, `site/`) — list its pages and identify the one(s) most thematically related to the change
+   - Inline godoc / API reference comments on the new exported symbols
+   - `CHANGELOG.md` if the project keeps one
+   - Any `examples/` directory entries that demonstrate the affected area
+
+3. **Audit each surface** with `grep`:
+   - Search for the names of related existing APIs (e.g. if you added `IterTools`, grep for `ListTools`) to find every page that already discusses the area
+   - Decide for each hit: does it need a cross-reference, a side-by-side comparison, or to stay untouched?
+
+4. **Decide where new content lives**:
+   - Prefer extending an existing page over creating a new one
+   - For a docs site, place new sections near related content (check the page's `## Heading` outline first)
+   - Skip surfaces that genuinely don't apply (e.g. a server-focused README for a client-only change) and say so explicitly
+
+5. **Draft the updates**:
+   - Lead with a one-sentence statement of what's new and why
+   - Show concrete code examples copied from real signatures — verify against the source files
+   - Include a comparison / "when to use which" table when adding an alternative to an existing API
+   - Note backwards-compatibility behaviour if relevant
+
+6. **Verify the docs build** before committing:
+   - For vocs / docusaurus / mkdocs sites, run the local build command (e.g. `npx vocs build`, `mkdocs build`) and fix any MDX/markdown errors
+   - For godoc, run `go vet ./...` and `go doc <pkg> <Symbol>` to sanity-check rendering
+
+7. **Report**:
+   - List every file changed and every file deliberately left alone (with a one-line reason)
+   - Suggest the next step (typically `/commit-push`) — do not auto-commit unless asked
+
+## Guidelines
+
+- Read the diff before writing anything — invented API names erode trust faster than missing docs
+- One change per doc commit; keep doc updates separate from code changes when possible
+- Match the existing voice and formatting of each surface (headings, code-fence languages, table styles)
+- Prefer linking between pages over duplicating content
+
+$@

.opencode/opencode.jsonc

@@ -1,8 +0,0 @@
-{
-  "$schema": "https://opencode.ai/config.json",
-  "permission": {
-    "external_directory": {
-      "~/go/**": "deny"
-    }
-  }
-}

AGENTS.md

@@ -1,22 +1,3 @@
-<!-- OPENSPEC:START -->
-# OpenSpec Instructions
-
-These instructions are for AI assistants working in this project.
-
-Always open `@/openspec/AGENTS.md` when the request:
-- Mentions planning or proposals (words like proposal, spec, change, plan)
-- Introduces new capabilities, breaking changes, architecture shifts, or big performance/security work
-- Sounds ambiguous and you need the authoritative spec before coding
-
-Use `@/openspec/AGENTS.md` to learn:
-- How to create and apply change proposals
-- Spec format and conventions
-- Project structure and guidelines
-
-Keep this managed block so 'openspec update' can refresh the instructions.
-
-<!-- OPENSPEC:END -->
-
 # KIT Agent Guidelines
 
 ## Build/Test Commands
@@ -42,6 +23,33 @@ Keep this managed block so 'openspec update' can refresh the instructions.
 - **Extension system** (`internal/extensions/`): Yaegi-interpreted Go, 13 lifecycle events, custom tools/commands/widgets/overlays/editor interceptors
 - **TUI** (`internal/ui/`): Bubble Tea v2 parent-child model (`AppModel` → `InputComponent`, `StreamComponent`, etc.)
 - **Decoupling pattern**: `cmd/root.go` has converter functions (e.g. `widgetProviderForUI()`) that bridge `internal/extensions/` types to `internal/ui/` types — the UI never imports extensions directly
+- **Public SDK** (`pkg/kit/`): The public-facing Go SDK for embedding Kit as a library. See rules below.
+
+## Public SDK (`pkg/kit/`) Rules
+
+`pkg/kit/` is the **public API surface** consumed by external Go developers. All exported symbols, types, function names, and godoc comments in this package are part of the SDK contract.
+
+### No Dependency Name Leakage
+Internal dependency names (e.g. `charm.land/fantasy`, library-specific jargon) **must not** appear in:
+- **Exported function/method names** — use generic terms (`LLM`, `Provider`, `Message`) instead of library names
+- **Exported type names** — type aliases should use domain names (e.g. `LLMMessage`, not `FantasyMessage`)
+- **Godoc comments** on exported symbols — these are visible in `go doc` output and pkg.go.dev
+- **Struct field names and tags** on exported types
+
+Using dependency types directly in **function bodies** (private implementation) is fine — that's invisible to SDK consumers.
+
+### Naming Conventions for SDK Symbols
+- Type aliases re-exporting dependency types: use `LLM*` prefix (e.g. `LLMMessage`, `LLMUsage`, `LLMResponse`)
+- Conversion helpers: use `ConvertToLLM*` / `ConvertFromLLM*` (not the dependency name)
+- Provider queries: use `GetLLMProviders` (not `GetFantasyProviders`)
+- When wrapping internal methods, the `pkg/kit/` name should be dependency-agnostic even if the `internal/` method still uses the old name
+
+### Deprecation Pattern
+When renaming a public SDK symbol, keep the old name as a deprecated wrapper for one release cycle:
+```go
+// Deprecated: Use NewName instead.
+func OldName() { return NewName() }
+```
 
 ## Key Patterns
 
@@ -92,3 +100,21 @@ Positional args are the prompt. `@file` args attach file content. Key flags: `--
 - Never guess or manually search the filesystem for external projects
 - Example: `btca ask -r https://github.com/user/repo -q "How does X work?"`
 - See `.agents/skills/btca-cli/SKILL.md` for full btca usage
+
+## BTCA Configured Resources
+The following external repositories are configured in `btca.config.jsonc` for research:
+
+- bubbletea
+- lipgloss
+- bubbles
+- glamour
+- fantasy
+- catwalk
+- crush
+- pi
+- iteratr
+- yaegi
+- acp-go-sdk
+- opencode
+- herald
+- herald-md

README.md

@@ -18,7 +18,8 @@ A powerful, extensible AI coding agent CLI with multi-provider support, built-in
 ## Features
 
 - **Multi-Provider LLM Support**: Anthropic, OpenAI, Google Gemini, Ollama, Azure OpenAI, AWS Bedrock, OpenRouter, and more
-- **Built-in Core Tools**: bash, read, write, edit, grep, find, ls, spawn_subagent - no MCP overhead
+- **Built-in Core Tools**: bash (with interactive sudo password prompt), read, write, edit, grep, find, ls, subagent - no MCP overhead
+- **Smart @ Attachments**: Binary files auto-detected via MIME type, MCP resources via `@mcp:server:uri`
 - **MCP Integration**: Connect external MCP servers for expanded capabilities
 - **Extension System**: Write custom tools, commands, widgets, and UI modifications in Go
 - **Theming**: 22 built-in color themes (KITT, Catppuccin, Dracula, Nord, etc.) with runtime switching, persistence, and custom theme files
@@ -28,7 +29,7 @@ A powerful, extensible AI coding agent CLI with multi-provider support, built-in
 - **Session Management**: Tree-based conversation history with branching support
 - **Non-Interactive Mode**: Script-friendly positional args with JSON output
 - **ACP Server**: Run Kit as an [Agent Client Protocol](https://agentclientprotocol.com) agent over stdio
-- **Go SDK**: Embed Kit in your own applications
+- **Go SDK**: Embed Kit in your own applications with full agent lifecycle events (30+ event types) and behavior-modifying hooks
 
 ## Installation
 
@@ -125,8 +126,20 @@ model: anthropic/claude-sonnet-latest
 max-tokens: 4096
 temperature: 0.7
 stream: true
+thinking-level: off       # off, none, minimal, low, medium, high
+no-core-tools: false      # set to true to disable all built-in core tools
+
+# Skills — all three keys are optional
+no-skills: false          # set to true to disable all skill loading
+skill:                    # explicit skill files/dirs (disables auto-discovery)
+  - /path/to/skill.md
+skills-dir: ""            # override project-local directory for auto-discovery
 ```
 
+All of the above keys can also be set programmatically via the SDK
+(`kit.Options.MaxTokens`, `Options.Temperature`, `Options.ThinkingLevel`, etc.)
+without touching config files — see [SDK options](#with-options).
+
 ### Environment Variables
 
 ```bash
@@ -151,6 +164,16 @@ mcpServers:
   search:
     type: remote
     url: "https://mcp.example.com/search"
+
+  pubmed:
+    type: remote
+    url: "https://pubmed.mcp.example.com"
+    noOAuth: true  # skip OAuth for public servers that don't require auth
+
+  builds:
+    type: remote
+    url: "https://builds.mcp.example.com"
+    tasksMode: always  # async task execution — see MCP Tasks below
 ```
 
 ## CLI Reference
@@ -179,19 +202,27 @@ mcpServers:
 --compact                Enable compact output mode
 --auto-compact           Auto-compact conversation near context limit
 
-# Extensions
+# Extensions and tools
 --extension, -e          Load additional extension file(s) (repeatable)
 --no-extensions          Disable all extensions
+--no-core-tools          Disable all built-in core tools (bash, read, write, edit, grep, find, ls, subagent)
 --prompt-template        Load a specific prompt template by name
 --no-prompt-templates    Disable prompt template loading
 
+# Skills
+--skill                  Load skill file or directory (repeatable)
+--skills-dir             Override the project-local skills directory for auto-discovery
+--no-skills              Disable skill loading (auto-discovery and explicit)
+
 # Generation parameters
---max-tokens             Maximum tokens in response (default: 4096)
+--max-tokens             Maximum tokens in response (default: 8192, auto-raised up to 32768 for models with larger known output limits)
 --temperature            Randomness 0.0-1.0 (default: 0.7)
 --top-p                  Nucleus sampling 0.0-1.0 (default: 0.95)
 --top-k                  Limit top K tokens (default: 40)
 --stop-sequences         Custom stop sequences (comma-separated)
---thinking-level         Extended thinking level: off, minimal, low, medium, high (default: off)
+--frequency-penalty      Penalize frequent tokens 0.0-2.0 (default: 0.0)
+--presence-penalty       Penalize present tokens 0.0-2.0 (default: 0.0)
+--thinking-level         Extended thinking level: off, none, minimal, low, medium, high (default: off)
 
 # System
 --config                 Config file path (default: ~/.kit.yml)
@@ -203,13 +234,18 @@ mcpServers:
 
 ```bash
 # Authentication (for OAuth-enabled providers)
-kit auth login [provider]    # Start OAuth flow (e.g., anthropic)
-kit auth logout [provider]   # Remove credentials for provider
-kit auth status              # Check authentication status
+kit auth login [provider]          # Start OAuth flow (e.g., anthropic)
+kit auth login [provider] --set-default  # Set provider's default model as system default
+kit auth logout [provider]         # Remove credentials for provider
+kit auth status                    # Check authentication status
+
+# GitHub Copilot login (experimental; requires active Copilot subscription)
+kit auth login copilot
+kit --model copilot/gpt-5.5 "Hello"
 
 # Model database
 kit models [provider]        # List available models (optionally filter by provider)
-kit models --all             # Show all providers (not just Fantasy-compatible)
+kit models --all             # Show all providers (not just LLM-compatible)
 kit update-models [source]   # Update model database (from models.dev, URL, file, or 'embedded')
 
 # Extension management
@@ -287,12 +323,15 @@ kit -e examples/extensions/minimal.go
 
 ### Extension Capabilities
 
-**Lifecycle Events**: OnSessionStart, OnSessionShutdown, OnBeforeAgentStart, OnAgentStart, OnAgentEnd, OnToolCall, OnToolExecutionStart, OnToolOutput, OnToolExecutionEnd, OnToolResult, OnInput, OnMessageStart, OnMessageUpdate, OnMessageEnd, OnModelChange, OnContextPrepare, OnBeforeFork, OnBeforeSessionSwitch, OnBeforeCompact, OnCustomEvent
+**Lifecycle Events**: OnSessionStart, OnSessionShutdown, OnBeforeAgentStart, OnAgentStart, OnAgentEnd, OnLLMUsage, OnToolCall, OnToolCallInputStart, OnToolCallInputDelta, OnToolCallInputEnd, OnToolExecutionStart, OnToolOutput, OnToolExecutionEnd, OnToolResult, OnInput, OnMessageStart, OnMessageUpdate, OnMessageEnd, OnModelChange, OnContextPrepare, OnBeforeFork, OnBeforeSessionSwitch, OnBeforeCompact, OnCustomEvent, OnSubagentStart, OnSubagentChunk, OnSubagentEnd
+
+`OnAgentEnd` carries per-turn aggregates (`ToolCallCount`, `ToolNames`, `LLMCallCount`, `InputTokensDelta`, `OutputTokensDelta`, `CostDelta`, `DurationMs`) so observers don't need to maintain parallel bookkeeping. `OnLLMUsage` fires after each LLM provider call with token + cost deltas attributed to that specific call/model — use it for accurate budget enforcement *between* calls instead of waiting for the turn to finish.
 
 **Custom Components**:
 - **Tools**: Add new tools the LLM can invoke
 - **Commands**: Register slash commands (e.g., `/mycommand`)
 - **Options**: Register configurable extension options
+- **Session State**: Last-write-wins key-value store via `ctx.SetState` / `GetState` / `DeleteState` / `ListState`, persisted to a per-session sidecar file outside the conversation tree
 - **Widgets**: Persistent status displays above/below input
 - **Headers/Footers**: Persistent content above/below the conversation
 - **Status Bar**: Custom status bar entries
@@ -307,41 +346,51 @@ kit -e examples/extensions/minimal.go
 - **Themes**: Register and switch color themes via `RegisterTheme`, `SetTheme`, `ListThemes`
 - **Custom Events**: Inter-extension communication via `EmitCustomEvent`
 
+**Bridged SDK APIs** (NEW): Extensions can now access internal SDK capabilities:
+- **Tree Navigation**: Navigate conversation history (`GetTreeNode`, `GetCurrentBranch`, `NavigateTo`), summarize branches (`SummarizeBranch`), and implement fresh context loops (`CollapseBranch`)
+- **Skill Loading**: Dynamically load and inject skills at runtime (`LoadSkill`, `DiscoverSkills`, `InjectSkillAsContext`)
+- **Template Parsing**: Parse and render templates with `{{variables}}` (`ParseTemplate`, `RenderTemplate`), parse CLI-style arguments (`ParseArguments`, `SimpleParseArguments`), and evaluate model conditionals (`EvaluateModelConditional`, `RenderWithModelConditionals`)
+- **Model Resolution**: Resolve model fallback chains (`ResolveModelChain`), query model capabilities (`GetModelCapabilities`, `CheckModelAvailable`), and extract provider/model ID (`GetCurrentProvider`, `GetCurrentModelID`)
+
 ### Extension Examples
 
 See the `examples/extensions/` directory:
 
-- `minimal.go` - Clean UI with custom footer
-- `auto-commit.go` - Auto-commit on shutdown
-- `bookmark.go` - Bookmark conversations
-- `branded-output.go` - Branded output rendering
-- `compact-notify.go` - Notification on compaction
-- `confirm-destructive.go` - Confirm destructive operations
-- `context-inject.go` - Inject context into conversations
-- `custom-editor-demo.go` - Vim-like modal editor
-- `dev-reload.go` - Development live-reload
-- `header-footer-demo.go` - Custom headers and footers
-- `inline-bash.go` - Inline bash execution
-- `interactive-shell.go` - Interactive shell integration
-- `kit-kit.go` - Kit-in-Kit (sub-agent spawning)
-- `lsp-diagnostics.go` - LSP diagnostic integration
-- `notify.go` - Desktop notifications
-- `overlay-demo.go` - Modal dialogs
-- `permission-gate.go` - Permission gating for tools
-- `pirate.go` - Pirate-themed personality
-- `plan-mode.go` - Read-only planning mode
-- `project-rules.go` - Project-specific rules
-- `prompt-demo.go` - Interactive prompts (select/confirm/input)
-- `protected-paths.go` - Path protection for sensitive files
-- `subagent-widget.go` - Multi-agent orchestration with status widget
-- `subagent-test.go` - Subagent testing utilities
-- `summarize.go` - Conversation summarization
-- `tool-logger.go` - Log all tool calls
-- `neon-theme.go` - Custom theme registration and switching
-- `tool-renderer-demo.go` - Custom tool call rendering
-- `widget-status.go` - Persistent status widgets
+- [`minimal.go`](examples/extensions/minimal.go) - Clean UI with custom footer
+- [`auto-commit.go`](examples/extensions/auto-commit.go) - Auto-commit on shutdown
+- [`bookmark.go`](examples/extensions/bookmark.go) - Bookmark conversations
+- [`branded-output.go`](examples/extensions/branded-output.go) - Branded output rendering
+- [`bridge-demo.go`](examples/extensions/bridge_demo.go) - Bridged SDK API demo (tree navigation, skills, templates, model resolution)
+- [`compact-notify.go`](examples/extensions/compact-notify.go) - Notification on compaction
+- [`confirm-destructive.go`](examples/extensions/confirm-destructive.go) - Confirm destructive operations
+- [`context-inject.go`](examples/extensions/context-inject.go) - Inject context into conversations
+- [`conversation-manager.go`](examples/extensions/conversation-manager.go) - **NEW** Tree navigation, branch summarization, and fresh context loops
+- [`custom-editor-demo.go`](examples/extensions/custom-editor-demo.go) - Vim-like modal editor
+- [`dev-reload.go`](examples/extensions/dev-reload.go) - Development live-reload
+- [`header-footer-demo.go`](examples/extensions/header-footer-demo.go) - Custom headers and footers
+- [`inline-bash.go`](examples/extensions/inline-bash.go) - Inline bash execution
+- [`interactive-shell.go`](examples/extensions/interactive-shell.go) - Interactive shell integration
+- [`kit-kit.go`](examples/extensions/kit-kit.go) - Kit-in-Kit (sub-agent spawning)
+- [`lsp-diagnostics.go`](examples/extensions/lsp-diagnostics.go) - LSP diagnostic integration
+- [`notify.go`](examples/extensions/notify.go) - Desktop notifications
+- [`overlay-demo.go`](examples/extensions/overlay-demo.go) - Modal dialogs
+- [`permission-gate.go`](examples/extensions/permission-gate.go) - Permission gating for tools
+- [`pirate.go`](examples/extensions/pirate.go) - Pirate-themed personality
+- [`plan-mode.go`](examples/extensions/plan-mode.go) - Read-only planning mode
+- [`project-rules.go`](examples/extensions/project-rules.go) - Project-specific rules
+- [`prompt-demo.go`](examples/extensions/prompt-demo.go) - Interactive prompts (select/confirm/input)
+- [`prompt-templates.go`](examples/extensions/prompt-templates.go) - **NEW** Frontmatter-driven templates with model switching and skill injection
+- [`protected-paths.go`](examples/extensions/protected-paths.go) - Path protection for sensitive files
+- [`subagent-widget.go`](examples/extensions/subagent-widget.go) - Multi-agent orchestration with status widget
+- [`subagent-test.go`](examples/extensions/subagent-test.go) - Subagent testing utilities
+- [`summarize.go`](examples/extensions/summarize.go) - Conversation summarization
+- [`tool-logger.go`](examples/extensions/tool-logger.go) - Log all tool calls
+- [`neon-theme.go`](examples/extensions/neon-theme.go) - Custom theme registration and switching
+- [`tool-renderer-demo.go`](examples/extensions/tool-renderer-demo.go) - Custom tool call rendering
+- [`usage-budget.go`](examples/extensions/usage-budget.go) - Per-call usage callback (`OnLLMUsage`), session state, and enriched `OnAgentEnd` per-turn report
+- [`widget-status.go`](examples/extensions/widget-status.go) - Persistent status widgets
 
-Also see `.kit/extensions/go-edit-lint.go` (in this repo) for a project-local extension example that runs gopls and golangci-lint on Go file edits.
+Also see [`.kit/extensions/go-edit-lint.go`](.kit/extensions/go-edit-lint.go) (in this repo) for a project-local extension example that runs gopls and golangci-lint on Go file edits.
 
 ### Loading Extensions
 
@@ -398,7 +447,7 @@ func TestMyExtension(t *testing.T) {
 - `AssertPrinted()`, `AssertPrintedContains()` — Verify output
 - `AssertToolRegistered()`, `AssertCommandRegistered()` — Verify registration
 
-See `examples/extensions/tool-logger_test.go` for a complete example with 14 test cases covering tool calls, input handling, and session lifecycle.
+See [`examples/extensions/tool-logger_test.go`](examples/extensions/tool-logger_test.go) for a complete example with 14 test cases covering tool calls, input handling, and session lifecycle.
 
 ### Prompt Templates
 
@@ -420,10 +469,13 @@ Focus on $1 specifically.
 
 **Argument placeholders:**
 - `$1`, `$2`, etc. — Individual arguments
-- `$@` or `$ARGUMENTS` — All arguments
+- `$@` or `$ARGUMENTS` — All arguments (zero or more)
+- `$+` — All arguments (one or more required; error if none given)
 - `${@:2}` — Arguments from position 2 onwards
 - `${@:1:3}` — 3 arguments starting at position 1
 
+Placeholders inside fenced code blocks (```) and inline code spans are ignored.
+
 Disable templates with `--no-prompt-templates` or load a specific template with `--prompt-template <name>`.
 
 ## Session Management
@@ -469,9 +521,20 @@ During an interactive session, use these slash commands:
 | `/import <path>` | Import and switch to a session from a JSONL file |
 | `/share` | Upload session to GitHub Gist and get a shareable viewer URL |
 | `/tree` | Navigate the session tree |
-| `/fork` | Branch from an earlier message |
+| `/fork` | Fork to new session from an earlier message |
 | `/new` | Start a fresh session |
 
+### Keyboard Shortcuts
+
+| Shortcut | Description |
+|----------|-------------|
+| `Ctrl+V` | Paste an image from the clipboard — shows an inline low-res thumbnail preview (tmux/zellij-safe) |
+| `Ctrl+U` | Clear all pending image attachments |
+| `Ctrl+X e` | Open `$VISUAL`/`$EDITOR` to compose or edit your prompt |
+| `Ctrl+X s` | Steer — inject a system-level instruction mid-turn |
+| `ESC ESC` | Cancel the current operation (tool call or streaming) |
+| `↑` / `↓` | Navigate prompt history |
+
 ## Go SDK
 
 Embed Kit in your Go applications:
@@ -494,7 +557,7 @@ func main() {
     if err != nil {
         log.Fatal(err)
     }
-    defer host.Close()
+    defer func() { _ = host.Close() }()
     
     // Send a prompt
     response, err := host.Prompt(ctx, "What is 2+2?")
@@ -514,16 +577,37 @@ host, err := kit.New(ctx, &kit.Options{
     SystemPrompt: "You are a helpful bot",
     ConfigFile:   "/path/to/config.yml",
     MaxSteps:     10,
-    Streaming:    true,
+    Streaming:    ptr(true), // *bool: nil = unset (default true), &false = off
     Quiet:        true,
 
+    // Generation parameters (override env/config/per-model defaults)
+    MaxTokens:        16384,             // 0 = auto-resolve (env → config → per-model → 8192 floor)
+    ThinkingLevel:    "medium",          // "off", "none", "minimal", "low", "medium", "high"
+    Temperature:      ptr(float32(0.2)), // pointer so 0.0 != unset; nil = provider default
+    TopP:             nil,                // nil = leave provider/per-model default
+    TopK:             nil,
+    FrequencyPenalty: nil,
+    PresencePenalty:  nil,
+
+    // Provider configuration (override env/config without reaching into viper)
+    ProviderAPIKey: "sk-...",                      // "" = use config / provider env var
+    ProviderURL:    "https://proxy.internal/v1",   // "" = provider default
+    TLSSkipVerify:  false,                         // only takes effect when true
+
     // Session options
     SessionPath:  "./session.jsonl",  // Open specific session
     Continue:     true,                // Resume most recent session
     NoSession:    true,                // Ephemeral mode
 
     // Tool options
-    ExtraTools:   []kit.Tool{...},     // Additional tools alongside defaults
+    Tools:            []kit.Tool{...},     // Replace default tool set entirely
+    ExtraTools:       []kit.Tool{...},     // Add tools alongside defaults
+    DisableCoreTools: true,                // Disable all built-in core tools; also controllable via
+                                           // --no-core-tools flag, KIT_NO_CORE_TOOLS env var,
+                                           // or no-core-tools: true in .kit.yml
+
+    // Configuration
+    SkipConfig:   true,                   // Skip .kit.yml files (viper defaults + env vars still apply)
 
     // Compaction
     AutoCompact:  true,                // Auto-compact near context limit
@@ -532,26 +616,174 @@ host, err := kit.New(ctx, &kit.Options{
 })
 ```
 
+**Generation & provider fields** (added in v0.55+) let SDK consumers configure
+Kit entirely in-code without `viper.Set()` workarounds or shipping a `.kit.yml`.
+Precedence is `Options` > `KIT_*` env vars > `.kit.yml` > per-model defaults
+(`modelSettings` / `customModels`) > provider-level defaults. Sampling params
+are pointer types so explicit `0.0` is distinguishable from "leave alone"; a
+non-zero `MaxTokens` suppresses automatic right-sizing the same way `--max-tokens`
+does on the CLI.
+
+### Functional options (`NewAgent`)
+
+For simple programmatic setups, `kit.NewAgent` offers an ergonomic
+functional-options front door over `kit.New`. Streaming is **enabled by
+default**; pass `kit.WithStreaming(false)` to opt out.
+
+```go
+host, err := kit.NewAgent(ctx,
+    kit.WithModel("anthropic/claude-sonnet-4-5-20250929"),
+    kit.WithSystemPrompt("You are a helpful assistant."),
+    kit.WithMaxTokens(8192),
+    kit.WithThinkingLevel("medium"),
+    kit.Ephemeral(), // in-memory session, no persistence
+)
+```
+
+Available options: `WithModel`, `WithSystemPrompt`, `WithStreaming`,
+`WithMaxTokens`, `WithThinkingLevel`, `WithTools`, `WithExtraTools`,
+`WithProviderAPIKey`, `WithProviderURL`, `WithConfigFile`, `WithDebug`, and
+`Ephemeral`. For advanced configuration not covered by the helpers (custom MCP
+config, in-process MCP servers, session backends, MCP task tuning) construct an
+`Options` value explicitly and call `kit.New`.
+
+### Per-instance config isolation
+
+Each `kit.New` / `kit.NewAgent` call owns an **isolated configuration store**,
+so constructing multiple Kit instances in the same process is safe: setting the
+model, thinking level, or generation parameters on one never affects another,
+and runtime mutators (`SetModel`, `SetThinkingLevel`) only touch the owning
+instance. This makes subagent spawning and multi-Kit embedding race-free with
+no external synchronization required.
+
+### MCP OAuth (remote MCP servers)
+
+When a remote MCP server returns 401, Kit runs the full OAuth flow (dynamic
+client registration → PKCE → token exchange → persistence) but delegates the
+user-facing step — showing the authorization URL and receiving the callback —
+to an `MCPAuthHandler` that you pass explicitly via `Options.MCPAuthHandler`.
+If nil, OAuth is disabled and the authorization-required error surfaces to the
+caller; the SDK never auto-opens a browser or binds a localhost port.
+
+```go
+// CLI/TUI apps: opens the system browser + prints status to stderr.
+authHandler, _ := kit.NewCLIMCPAuthHandler()
+defer authHandler.Close()
+
+host, _ := kit.New(ctx, &kit.Options{
+    MCPAuthHandler: authHandler,
+})
+
+// Custom UX: reuse the SDK's port + callback server, supply your own
+// presentation via OnAuthURL (TUI modal, QR code, web redirect, etc.).
+//   h, _ := kit.NewDefaultMCPAuthHandler()
+//   h.OnAuthURL = func(server, authURL string) { myUI.Show(server, authURL) }
+//
+// Full control (web apps, daemons): implement kit.MCPAuthHandler yourself —
+// no localhost binding, no side effects.
+```
+
+Tokens are persisted to `$XDG_CONFIG_HOME/.kit/mcp_tokens.json` by default; swap
+in a custom `MCPTokenStoreFactory` for encrypted, DB-backed, or in-memory
+storage. See the [SDK options docs](/sdk/options#mcp-oauth-authorization) for
+the full matrix.
+
+### MCP Tasks (long-running tools)
+
+Kit advertises [MCP task support](https://modelcontextprotocol.io/specification/2025-11-25/basic/utilities/tasks)
+during `initialize`, so cooperating MCP servers can respond to `tools/call`
+with a `taskId` instead of blocking the connection. Kit then polls
+`tasks/get` / `tasks/result` until the task reaches a terminal state, and
+best-effort `tasks/cancel`s on context cancellation.
+
+Defaults are safe — a server that doesn't advertise task capability runs
+synchronously, exactly as before. Opt in per server via `tasksMode` in
+`.kit.yml` (`auto` | `never` | `always`) or programmatically through the SDK:
+
+```go
+host, _ := kit.New(ctx, &kit.Options{
+    MCPTaskMode: map[string]kit.MCPTaskMode{
+        "build-server": kit.MCPTaskModeAlways,
+    },
+    MCPTaskTimeout:  15 * time.Minute,
+    MCPTaskProgress: func(p kit.MCPTaskProgress) {
+        log.Printf("%s: %s", p.TaskID, p.Status)
+    },
+})
+
+tasks, _ := host.ListMCPTasks(ctx, "build-server")
+_, _    = host.CancelMCPTask(ctx, "build-server", tasks[0].TaskID)
+```
+
+See the [configuration docs](/configuration#mcp-tasks-long-running-tools) and
+[SDK options → MCP Tasks](/sdk/options#mcp-tasks) for the full surface.
+
+### Custom Tools
+
+Create custom tools with automatic schema generation — no external dependencies needed:
+
+```go
+type SearchInput struct {
+    Query string `json:"query" description:"Search query"`
+}
+
+searchTool := kit.NewTool("search", "Search the codebase",
+    func(ctx context.Context, input SearchInput) (kit.ToolOutput, error) {
+        return kit.TextResult("Found: ..."), nil
+    },
+)
+
+host, _ := kit.New(ctx, &kit.Options{
+    ExtraTools: []kit.Tool{searchTool}, // adds alongside built-in tools
+})
+```
+
+Use `kit.NewParallelTool` for tools safe to run concurrently. Binary data (images, audio, etc.) in `ToolOutput.Data` is automatically forwarded to the LLM when `MediaType` is set. See the [SDK docs](/sdk/overview) for full details on struct tags, `ToolOutput` fields, and `ToolCallIDFromContext`.
+
+#### Return Helpers
+
+| Helper | Description |
+| --- | --- |
+| `kit.TextResult(content)` | Successful text result |
+| `kit.ErrorResult(content)` | Error result (LLM sees it as a tool error) |
+| `kit.ImageResult(content, data, mediaType)` | Image result with binary data (e.g. `"image/png"`) |
+| `kit.MediaResult(content, data, mediaType)` | Non-image media result (e.g. `"audio/mpeg"`) |
+
+#### ToolOutput Fields
+
+```go
+kit.ToolOutput{
+    Content:   "result text",     // text returned to the LLM
+    IsError:   false,             // true = LLM sees this as an error
+    Data:      pngBytes,          // optional binary data (images, audio)
+    MediaType: "image/png",       // MIME type for binary Data
+    Metadata:  map[string]any{},  // opaque metadata for hooks/UI (not sent to LLM)
+}
+```
+
 ### With Callbacks
 
 ```go
-response, err := host.PromptWithCallbacks(
+unsub := host.OnToolCall(func(e kit.ToolCallEvent) {
+    println("Calling tool:", e.ToolName)
+})
+defer unsub()
+
+unsub2 := host.OnToolResult(func(e kit.ToolResultEvent) {
+    if e.IsError {
+        println("Tool failed:", e.ToolName)
+    }
+})
+defer unsub2()
+
+unsub3 := host.OnMessageUpdate(func(e kit.MessageUpdateEvent) {
+    print(e.Chunk)
+})
+defer unsub3()
+
+response, err := host.Prompt(
     ctx,
     "List files in current directory",
-    func(name, args string) {
-        // Tool call started
-        println("Calling tool:", name)
-    },
-    func(name, args, result string, isError bool) {
-        // Tool call completed
-        if isError {
-            println("Tool failed:", name)
-        }
-    },
-    func(chunk string) {
-        // Streaming text chunk
-        print(chunk)
-    },
 )
 ```
 
@@ -581,6 +813,45 @@ host, _ := kit.New(ctx, &kit.Options{
 })
 ```
 
+### Runtime Skills & Context Files
+
+For multi-tenant hosts (chatbots, per-user agents, web services), the SDK
+lets you swap skills and `AGENTS.md`-style context files **after** Kit
+construction. Every mutation recomposes the system prompt and applies it to
+the agent so the next turn picks up the new instructions — no restart needed.
+
+```go
+// Programmatic skill (no file on disk required).
+host.AddSkill(&kit.Skill{
+    Name:        "polite-french",
+    Description: "Respond in French and always greet the user.",
+    Content:     "Always reply in French. Open every response with 'Bonjour'.",
+})
+
+// Or load one from disk.
+host.LoadAndAddSkill("/var/skills/refund-policy.md")
+
+// Per-user AGENTS.md content pulled from a database.
+host.AddContextFileContent(
+    fmt.Sprintf("session://%s/AGENTS.md", userID),
+    rulesFromDB,
+)
+
+// Tear down session-specific state on logout.
+host.RemoveSkill("polite-french")
+host.RemoveContextFile(fmt.Sprintf("session://%s/AGENTS.md", userID))
+
+// Or replace the whole set atomically.
+host.SetSkills(activeSkillsForUser)
+host.SetContextFiles(activeContextForUser)
+```
+
+Skills dedupe by `Name`, context files dedupe by `Path` (which can be any
+opaque identifier — it doesn't have to be a real filesystem path). All
+mutators and readers (`GetSkills`, `GetContextFiles`) are safe to call
+concurrently from multiple goroutines. See the [SDK overview docs](/sdk/overview#runtime-skills-and-context-files)
+for the full reference.
+
 ## Advanced Usage
 
 ### Subagent Pattern
@@ -697,6 +968,7 @@ npm/                 - NPM package wrapper for distribution
 
 - **Anthropic** - Claude models (native, prompt caching, OAuth)
 - **OpenAI** - GPT models
+- **Copilot** - GitHub Copilot models (`copilot`, requires active Copilot subscription)
 - **Google** - Gemini models
 - **Ollama** - Local models
 - **Azure OpenAI** - Azure-hosted OpenAI
@@ -715,13 +987,38 @@ Use `custom/custom` when pointing Kit at any OpenAI-compatible endpoint with `--
 kit --provider-url "http://localhost:8080/v1" "Hello"
 ```
 
-This automatically defaults to `custom/custom` without needing to specify a model. The custom provider routes through fantasy's `openaicompat` provider and supports:
+This automatically defaults to `custom/custom` without needing to specify a model. The custom provider routes through the `openaicompat` provider and supports:
 
 - Zero cost tracking (input/output = 0)
 - 262K context window, 65K output limit
 - Reasoning and temperature support
 - Optional `CUSTOM_API_KEY` environment variable or `--provider-api-key` flag
 
+### Auto-routed Providers
+
+Any provider in the [models.dev](https://models.dev) database can be used as
+`provider/model` without a dedicated native integration. Kit auto-routes the
+request through the matching **wire protocol** based on the provider's npm package
+(or per-model override), using its `api` URL as the base:
+
+| npm package | Wire protocol |
+|-------------|---------------|
+| `@ai-sdk/openai` | OpenAI (Responses API) |
+| `@ai-sdk/openai-compatible` | OpenAI (chat completions) |
+| `@ai-sdk/anthropic` | Anthropic |
+| `@ai-sdk/google` | Google Gemini |
+
+Providers with an `api` URL but an unrecognized npm package fall back to the
+OpenAI-compatible wire. Because routing follows the wire protocol, aggregator/proxy
+providers work across all of their models — including Claude, GPT, *and* Gemini
+routes:
+
+```bash
+kit --model opencode/claude-haiku-4-5 "Hello"     # → Anthropic wire
+kit --model opencode/gpt-5 "Hello"                # → OpenAI wire
+kit --model opencode/gemini-3.5-flash "Hello"     # → Google wire
+```
+
 ### Model String Format
 
 ```bash

btca.config.jsonc

@@ -76,6 +76,18 @@
       "name": "opencode",
       "url": "https://github.com/anomalyco/opencode",
       "branch": "dev"
+    },
+    {
+      "type": "git",
+      "name": "herald",
+      "url": "https://github.com/indaco/herald",
+      "branch": "main"
+    },
+    {
+      "type": "git",
+      "name": "herald-md",
+      "url": "https://github.com/indaco/herald-md",
+      "branch": "main"
     }
   ],
   "model": "claude-haiku-4-5",

cmd/acp.go

@@ -11,6 +11,7 @@ import (
 	"os/signal"
 	"syscall"
 
+	"github.com/charmbracelet/log"
 	acp "github.com/coder/acp-go-sdk"
 
 	"github.com/mark3labs/kit/internal/acpserver"
@@ -54,6 +55,8 @@ func runACP(cmd *cobra.Command, _ []string) error {
 		conn.SetLogger(slog.New(slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{
 			Level: slog.LevelDebug,
 		})))
+		// Also set charmbracelet/log level for acpserver package logging
+		log.SetLevel(log.DebugLevel)
 	}
 
 	// Wait for either the client to disconnect or a signal.

cmd/auth.go

@@ -1,12 +1,17 @@
 package cmd
 
 import (
+	"context"
 	"fmt"
+	"net"
+	"net/http"
 	"os"
 	"strings"
+	"time"
 
 	"charm.land/huh/v2"
 	"github.com/mark3labs/kit/internal/auth"
+	"github.com/mark3labs/kit/internal/ui"
 	kit "github.com/mark3labs/kit/pkg/kit"
 	"github.com/spf13/cobra"
 )
@@ -14,7 +19,7 @@ import (
 // authCmd represents the auth command for managing AI provider authentication.
 // This command provides subcommands for login, logout, and status checking
 // of authentication credentials for various AI providers, with OAuth support
-// for providers like Anthropic.
+// for providers like Anthropic and OpenAI.
 var authCmd = &cobra.Command{
 	Use:   "auth",
 	Short: "Manage authentication credentials for AI providers",
@@ -25,9 +30,13 @@ using OAuth flows. Stored credentials take precedence over environment variables
 
 Available providers:
   - anthropic: Anthropic Claude API (OAuth)
+  - openai:    OpenAI API (OAuth and API key)
+  - copilot:   GitHub Copilot (GitHub device login)
 
 Examples:
   kit auth login anthropic
+  kit auth login openai
+  kit auth login copilot
   kit auth logout anthropic
   kit auth status`,
 }
@@ -46,9 +55,17 @@ environment variables when making API calls.
 
 Available providers:
   - anthropic: Anthropic Claude API (OAuth)
+  - openai:    OpenAI ChatGPT Plus/Pro (Codex OAuth)
+  - copilot:   GitHub Copilot (GitHub device login, experimental)
 
-Example:
-  kit auth login anthropic`,
+Flags:
+  --set-default   Set this provider's default model as the system default
+
+Examples:
+  kit auth login anthropic
+  kit auth login openai
+  kit auth login copilot
+  kit auth login copilot --set-default`,
 	Args: cobra.ExactArgs(1),
 	RunE: runAuthLogin,
 }
@@ -61,14 +78,18 @@ var authLogoutCmd = &cobra.Command{
 	Short: "Remove stored authentication credentials for a provider",
 	Long: `Remove stored authentication credentials for an AI provider.
 
-This will delete the stored API key for the specified provider. You will need
-to use environment variables or command-line flags for authentication after logout.
+This will delete the stored API key or OAuth credentials for the specified provider. 
+You will need to use environment variables or command-line flags for authentication after logout.
 
 Available providers:
   - anthropic: Anthropic Claude API
+  - openai:    OpenAI API
+  - copilot:   GitHub Copilot
 
 Example:
-  kit auth logout anthropic`,
+  kit auth logout anthropic
+  kit auth logout openai
+  kit auth logout copilot`,
 	Args: cobra.ExactArgs(1),
 	RunE: runAuthLogout,
 }
@@ -89,20 +110,59 @@ Example:
 	RunE: runAuthStatus,
 }
 
+var (
+	loginSetDefault bool
+)
+
+// defaultModels maps providers to their recommended default models.
+// These are used when --set-default flag is passed to auth login.
+var defaultModels = map[string]string{
+	"anthropic": "anthropic/claude-sonnet-4-5-20250929",
+	"openai":    "openai/gpt-5.4",
+	"copilot":   "copilot/gpt-5.5",
+}
+
+// setDefaultModelIfRequested sets the default model for the given provider
+// if the --set-default flag was provided.
+func setDefaultModelIfRequested(provider string) error {
+	if !loginSetDefault {
+		return nil
+	}
+
+	model, ok := defaultModels[provider]
+	if !ok {
+		return fmt.Errorf("no default model configured for provider: %s", provider)
+	}
+
+	if err := ui.SaveModelPreference(model); err != nil {
+		return fmt.Errorf("failed to save model preference: %w", err)
+	}
+
+	fmt.Printf("\n✓ Set default model to: %s\n", model)
+	return nil
+}
+
 func init() {
 	authCmd.AddCommand(authLoginCmd)
 	authCmd.AddCommand(authLogoutCmd)
 	authCmd.AddCommand(authStatusCmd)
+
+	authLoginCmd.Flags().BoolVar(&loginSetDefault, "set-default", false, "Set this provider's default model as the system default after login")
 }
 
+// runAuthLogin dispatches OAuth login to the selected provider.
 func runAuthLogin(cmd *cobra.Command, args []string) error {
 	provider := strings.ToLower(args[0])
 
 	switch provider {
 	case "anthropic":
 		return loginAnthropic()
+	case "openai":
+		return loginOpenAI()
+	case "copilot":
+		return loginCopilot(cmd.Context())
 	default:
-		return fmt.Errorf("unsupported provider: %s. Available providers: anthropic", provider)
+		return fmt.Errorf("unsupported provider: %s. Available providers: anthropic, openai, copilot", provider)
 	}
 }
 
@@ -112,8 +172,12 @@ func runAuthLogout(cmd *cobra.Command, args []string) error {
 	switch provider {
 	case "anthropic":
 		return logoutAnthropic()
+	case "openai":
+		return logoutOpenAI()
+	case "copilot":
+		return logoutCopilot()
 	default:
-		return fmt.Errorf("unsupported provider: %s. Available providers: anthropic", provider)
+		return fmt.Errorf("unsupported provider: %s. Available providers: anthropic, openai, copilot", provider)
 	}
 }
 
@@ -157,8 +221,66 @@ func runAuthStatus(cmd *cobra.Command, args []string) error {
 		}
 	}
 
+	// Check OpenAI credentials
+	fmt.Print("\nOpenAI: ")
+	if hasOpenAICreds, err := cm.HasOpenAICredentials(); err != nil {
+		fmt.Printf("Error checking credentials: %v\n", err)
+	} else if hasOpenAICreds {
+		if creds, err := cm.GetOpenAICredentials(); err != nil {
+			fmt.Printf("Error reading credentials: %v\n", err)
+		} else {
+			authType := "API Key"
+			status := "✓ Authenticated"
+
+			if creds.Type == "oauth" {
+				authType = "OAuth (ChatGPT/Codex)"
+				if creds.IsExpired() {
+					status = "⚠️  Token expired (will refresh automatically)"
+				} else if creds.NeedsRefresh() {
+					status = "⚠️  Token expires soon (will refresh automatically)"
+				}
+			}
+
+			accountInfo := ""
+			if creds.Type == "oauth" && creds.AccountID != "" {
+				accountInfo = fmt.Sprintf(" [%s]", creds.AccountID)
+			}
+
+			fmt.Printf("%s (%s%s, stored %s)\n", status, authType, accountInfo, creds.CreatedAt.Format("2006-01-02 15:04:05"))
+		}
+	} else {
+		fmt.Println("✗ Not authenticated")
+		// Check if environment variable is set
+		if os.Getenv("OPENAI_API_KEY") != "" {
+			fmt.Println("  (OPENAI_API_KEY environment variable is set)")
+		}
+	}
+
+	// Check GitHub Copilot credentials
+	fmt.Print("\nGitHub Copilot: ")
+	if hasCopilotCreds, err := cm.HasCopilotCredentials(); err != nil {
+		fmt.Printf("Error checking credentials: %v\n", err)
+	} else if hasCopilotCreds {
+		if creds, err := cm.GetCopilotCredentials(); err != nil {
+			fmt.Printf("Error reading credentials: %v\n", err)
+		} else {
+			status := "✓ Authenticated"
+			if creds.IsExpired() {
+				status = "⚠️  Token expired (will refresh automatically)"
+			} else if creds.NeedsRefresh() {
+				status = "⚠️  Token expires soon (will refresh automatically)"
+			}
+
+			fmt.Printf("%s (GitHub OAuth, stored %s)\n", status, creds.CreatedAt.Format("2006-01-02 15:04:05"))
+		}
+	} else {
+		fmt.Println("✗ Not authenticated")
+	}
+
 	fmt.Println("\nTo authenticate with a provider:")
 	fmt.Println("  kit auth login anthropic")
+	fmt.Println("  kit auth login openai")
+	fmt.Println("  kit auth login copilot")
 
 	return nil
 }
@@ -238,6 +360,17 @@ func loginAnthropic() error {
 	fmt.Println("\n🎉 Your OAuth credentials will now be used for Anthropic API calls.")
 	fmt.Println("💡 You can check your authentication status with: kit auth status")
 
+	// Set default model if requested
+	if err := setDefaultModelIfRequested("anthropic"); err != nil {
+		return err
+	}
+
+	// Remind users how to set this as default if they didn't use --set-default
+	if !loginSetDefault {
+		fmt.Println("\n💡 To set Anthropic as your default model, run:")
+		fmt.Println("   kit auth login anthropic --set-default")
+	}
+
 	return nil
 }
 
@@ -282,3 +415,376 @@ func logoutAnthropic() error {
 
 	return nil
 }
+
+func loginOpenAI() error {
+	cm, err := kit.NewCredentialManager()
+	if err != nil {
+		return fmt.Errorf("failed to initialize credential manager: %w", err)
+	}
+
+	// Check if already authenticated
+	if hasAuth, err := cm.HasOpenAICredentials(); err == nil && hasAuth {
+		var reauth bool
+		err := huh.NewConfirm().
+			Title("You are already authenticated with OpenAI (ChatGPT/Codex)").
+			Description("Do you want to re-authenticate?").
+			Affirmative("Yes").
+			Negative("No").
+			Value(&reauth).
+			Run()
+		if err != nil || !reauth {
+			fmt.Println("Authentication cancelled.")
+			return nil
+		}
+	}
+
+	// Create OAuth client
+	client := auth.NewOpenAIOAuthClient()
+
+	// Generate authorization URL
+	fmt.Println("🔐 Starting OAuth authentication with OpenAI (ChatGPT/Codex)...")
+	fmt.Println("This will open your browser to authenticate with your ChatGPT account.")
+	fmt.Println()
+
+	authData, err := client.GetAuthorizationURL()
+	if err != nil {
+		return fmt.Errorf("failed to generate authorization URL: %w", err)
+	}
+
+	// Start local callback server
+	callbackServer, err := startOpenAICallbackServer(authData.State)
+	if err != nil {
+		fmt.Printf("⚠️  Could not start local callback server: %v\n", err)
+		fmt.Println("Falling back to manual code entry.")
+	}
+	if callbackServer != nil {
+		defer callbackServer.Close()
+	}
+
+	// Display URL and try to open browser
+	fmt.Println("📱 Opening your browser for authentication...")
+	fmt.Println("If the browser doesn't open automatically, please visit this URL:")
+	fmt.Printf("\n%s\n\n", authData.URL)
+
+	// Try to open browser
+	auth.TryOpenBrowser(authData.URL)
+
+	// Wait for callback or manual input
+	var code string
+	if callbackServer != nil {
+		fmt.Println("Waiting for browser authentication...")
+		select {
+		case callbackCode := <-callbackServer.CodeChan:
+			if callbackCode != "" {
+				code = callbackCode
+				fmt.Println("✓ Received authorization code from browser callback.")
+			}
+		case <-time.After(2 * time.Minute):
+			fmt.Println("\n⏱️  Timeout waiting for browser callback.")
+			callbackServer.Close()
+		}
+	}
+
+	// If no code from callback, prompt for manual entry
+	if code == "" {
+		fmt.Println("\nAfter authorizing, paste the callback URL or authorization code below.")
+		fmt.Println("(The callback URL will look like: http://localhost:1455/auth/callback?code=...&state=...)")
+		fmt.Println()
+
+		var input string
+		err = huh.NewInput().
+			Title("Callback URL or Code").
+			Description("Paste the full callback URL or just the authorization code").
+			Value(&input).
+			Run()
+		if err != nil {
+			return fmt.Errorf("failed to read input: %w", err)
+		}
+		input = strings.TrimSpace(input)
+
+		if input == "" {
+			return fmt.Errorf("authorization code cannot be empty")
+		}
+
+		// Parse the input (could be full URL or just code)
+		parsedCode, parsedState := auth.ParseOpenAIAuthorizationInput(input)
+		if parsedCode == "" {
+			return fmt.Errorf("could not extract authorization code from input")
+		}
+
+		// Validate state if provided
+		if parsedState != "" && parsedState != authData.State {
+			return fmt.Errorf("state mismatch - possible security issue")
+		}
+		code = parsedCode
+	}
+
+	// Exchange code for tokens
+	fmt.Println("\n🔄 Exchanging authorization code for access token...")
+	creds, err := client.ExchangeCode(code, authData.Verifier)
+	if err != nil {
+		return fmt.Errorf("failed to exchange authorization code: %w", err)
+	}
+
+	// Store the credentials
+	if err := cm.SetOpenAIOAuthCredentials(creds); err != nil {
+		return fmt.Errorf("failed to store credentials: %w", err)
+	}
+
+	fmt.Println("✅ Successfully authenticated with OpenAI (ChatGPT/Codex)!")
+	fmt.Printf("📁 Credentials stored in: %s\n", cm.GetCredentialsPath())
+	fmt.Printf("👤 Account ID: %s\n", creds.AccountID)
+	fmt.Println("\n🎉 Your OAuth credentials will now be used for OpenAI API calls.")
+	fmt.Println("💡 You can check your authentication status with: kit auth status")
+
+	// Set default model if requested
+	if err := setDefaultModelIfRequested("openai"); err != nil {
+		return err
+	}
+
+	// Remind users how to set this as default if they didn't use --set-default
+	if !loginSetDefault {
+		fmt.Println("\n💡 To set OpenAI as your default model, run:")
+		fmt.Println("   kit auth login openai --set-default")
+	}
+
+	return nil
+}
+
+// loginCopilot authenticates GitHub Copilot using GitHub device flow.
+func loginCopilot(ctx context.Context) error {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+
+	cm, err := kit.NewCredentialManager()
+	if err != nil {
+		return fmt.Errorf("failed to initialize credential manager: %w", err)
+	}
+
+	if hasAuth, err := cm.HasCopilotCredentials(); err == nil && hasAuth {
+		var reauth bool
+		err := huh.NewConfirm().
+			Title("You are already authenticated with GitHub Copilot").
+			Description("Do you want to re-authenticate?").
+			Affirmative("Yes").
+			Negative("No").
+			Value(&reauth).
+			Run()
+		if err != nil {
+			return fmt.Errorf("failed to prompt for re-authentication: %w", err)
+		}
+		if !reauth {
+			fmt.Println("Authentication cancelled.")
+			return nil
+		}
+	}
+
+	client := auth.NewCopilotOAuthClient()
+
+	fmt.Println("🔐 Starting GitHub Copilot authentication...")
+	fmt.Println("This uses GitHub device login and requires an active GitHub Copilot subscription.")
+	fmt.Println("Experimental: this uses VS Code Copilot Chat client identifiers.")
+	fmt.Println()
+
+	deviceCode, err := client.StartDeviceFlow(ctx)
+	if err != nil {
+		return fmt.Errorf("failed to start GitHub device login: %w", err)
+	}
+
+	fmt.Println("📱 Open this page and enter the code:")
+	fmt.Printf("\n%s\n\n", deviceCode.VerificationURI)
+	fmt.Printf("Code: %s\n\n", deviceCode.UserCode)
+	auth.TryOpenBrowser(deviceCode.VerificationURI)
+
+	fmt.Println("Waiting for GitHub authorization...")
+	githubToken, err := client.PollDeviceToken(ctx, deviceCode)
+	if err != nil {
+		return fmt.Errorf("failed to complete GitHub device login: %w", err)
+	}
+
+	fmt.Println("\n🔄 Exchanging GitHub token for Copilot access token...")
+	creds, err := client.ExchangeGitHubToken(ctx, githubToken)
+	if err != nil {
+		return fmt.Errorf("failed to get GitHub Copilot token: %w", err)
+	}
+
+	if err := cm.SetCopilotOAuthCredentials(creds); err != nil {
+		return fmt.Errorf("failed to store credentials: %w", err)
+	}
+
+	fmt.Println("✅ Successfully authenticated with GitHub Copilot!")
+	fmt.Printf("📁 Credentials stored in: %s\n", cm.GetCredentialsPath())
+	fmt.Println("\n🎉 Your GitHub Copilot credentials will now be used for copilot/* models.")
+	fmt.Println("💡 You can check your authentication status with: kit auth status")
+
+	if err := setDefaultModelIfRequested("copilot"); err != nil {
+		return err
+	}
+
+	if !loginSetDefault {
+		fmt.Println("\n💡 To set Copilot as your default model, run:")
+		fmt.Println("   kit auth login copilot --set-default")
+	}
+
+	return nil
+}
+
+// callbackServer holds the HTTP server and channel for receiving the OAuth callback
+type callbackServer struct {
+	Server   *http.Server
+	CodeChan chan string
+	State    string
+}
+
+// Close shuts down the callback server
+func (cs *callbackServer) Close() {
+	if cs.Server != nil {
+		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+		_ = cs.Server.Shutdown(ctx)
+	}
+}
+
+// startOpenAICallbackServer starts a local HTTP server to receive the OAuth callback
+func startOpenAICallbackServer(expectedState string) (*callbackServer, error) {
+	codeChan := make(chan string, 1)
+
+	mux := http.NewServeMux()
+	server := &http.Server{
+		Addr:    "127.0.0.1:1455",
+		Handler: mux,
+	}
+
+	mux.HandleFunc("/auth/callback", func(w http.ResponseWriter, r *http.Request) {
+		// Check state
+		state := r.URL.Query().Get("state")
+		if state != expectedState {
+			http.Error(w, "State mismatch", http.StatusBadRequest)
+			return
+		}
+
+		code := r.URL.Query().Get("code")
+		if code == "" {
+			http.Error(w, "Missing authorization code", http.StatusBadRequest)
+			return
+		}
+
+		// Send code to channel
+		select {
+		case codeChan <- code:
+		default:
+		}
+
+		// Return success page
+		w.Header().Set("Content-Type", "text/html; charset=utf-8")
+		w.WriteHeader(http.StatusOK)
+		_, _ = fmt.Fprintf(w, `<!DOCTYPE html>
+<html>
+<head><title>Authentication Successful</title></head>
+<body style="font-family: sans-serif; text-align: center; padding: 50px;">
+<h1>&#10003; Authentication Successful</h1>
+<p>You can close this window and return to the terminal.</p>
+</body>
+</html>`)
+	})
+
+	// Try to start server
+	listener, err := net.Listen("tcp", "127.0.0.1:1455")
+	if err != nil {
+		return nil, fmt.Errorf("port 1455 not available: %w", err)
+	}
+	_ = listener.Close()
+
+	go func() {
+		_ = server.ListenAndServe()
+	}()
+
+	return &callbackServer{
+		Server:   server,
+		CodeChan: codeChan,
+		State:    expectedState,
+	}, nil
+}
+
+func logoutOpenAI() error {
+	cm, err := kit.NewCredentialManager()
+	if err != nil {
+		return fmt.Errorf("failed to initialize credential manager: %w", err)
+	}
+
+	// Check if authenticated
+	hasAuth, err := cm.HasOpenAICredentials()
+	if err != nil {
+		return fmt.Errorf("failed to check authentication status: %w", err)
+	}
+
+	if !hasAuth {
+		fmt.Println("You are not currently authenticated with OpenAI.")
+		return nil
+	}
+
+	// Confirm logout
+	var confirm bool
+	err = huh.NewConfirm().
+		Title("Remove OpenAI credentials").
+		Description("Are you sure you want to remove your stored credentials?").
+		Affirmative("Yes").
+		Negative("No").
+		Value(&confirm).
+		Run()
+	if err != nil || !confirm {
+		fmt.Println("Logout cancelled.")
+		return nil
+	}
+
+	// Remove credentials
+	if err := cm.RemoveOpenAICredentials(); err != nil {
+		return fmt.Errorf("failed to remove credentials: %w", err)
+	}
+
+	fmt.Println("✓ Successfully logged out from OpenAI!")
+	fmt.Println("You will need to use environment variables or command-line flags for authentication.")
+
+	return nil
+}
+
+func logoutCopilot() error {
+	cm, err := kit.NewCredentialManager()
+	if err != nil {
+		return fmt.Errorf("failed to initialize credential manager: %w", err)
+	}
+
+	hasAuth, err := cm.HasCopilotCredentials()
+	if err != nil {
+		return fmt.Errorf("failed to check authentication status: %w", err)
+	}
+
+	if !hasAuth {
+		fmt.Println("You are not currently authenticated with GitHub Copilot.")
+		return nil
+	}
+
+	var confirm bool
+	err = huh.NewConfirm().
+		Title("Remove GitHub Copilot credentials").
+		Description("Are you sure you want to remove your stored credentials?").
+		Affirmative("Yes").
+		Negative("No").
+		Value(&confirm).
+		Run()
+	if err != nil || !confirm {
+		fmt.Println("Logout cancelled.")
+		return nil
+	}
+
+	if err := cm.RemoveCopilotCredentials(); err != nil {
+		return fmt.Errorf("failed to remove credentials: %w", err)
+	}
+
+	fmt.Println("✓ Successfully logged out from GitHub Copilot!")
+	fmt.Println("You will need to authenticate again with 'kit auth login copilot'.")
+	fmt.Println("Tip: this removes local credentials only. Revoke the GitHub OAuth grant at https://github.com/settings/applications")
+
+	return nil
+}

cmd/extension_context.go

@@ -0,0 +1,308 @@
+package cmd
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"github.com/spf13/viper"
+	"golang.org/x/term"
+
+	"github.com/mark3labs/kit/internal/app"
+	"github.com/mark3labs/kit/internal/extbridge"
+	"github.com/mark3labs/kit/internal/extensions"
+	"github.com/mark3labs/kit/internal/models"
+	"github.com/mark3labs/kit/internal/ui"
+	kit "github.com/mark3labs/kit/pkg/kit"
+)
+
+// extensionContextDeps groups the runtime dependencies needed to wire up
+// an extensions.Context for the interactive TUI mode.
+type extensionContextDeps struct {
+	ctx          context.Context
+	cwd          string
+	modelName    string
+	interactive  bool
+	kitInstance  *kit.Kit
+	appInstance  *app.App
+	usageTracker *ui.UsageTracker
+}
+
+// buildInteractiveExtensionContext returns an extensions.Context with every
+// field except Print / PrintInfo / PrintError populated. Callers must set
+// the three print routes appropriately for their phase (startup buffering
+// vs. live runtime routing).
+//
+// The headless half (data access, state, options, tree navigation, skills,
+// templates, model resolution, subagents) comes from extbridge.BaseContext;
+// this function overlays the TUI-specific fields and overrides SetModel /
+// ReloadExtensions with TUI-aware versions.
+func buildInteractiveExtensionContext(deps extensionContextDeps) extensions.Context {
+	kitInstance := deps.kitInstance
+	appInstance := deps.appInstance
+	usageTracker := deps.usageTracker
+
+	ec := extbridge.BaseContext(deps.ctx, kitInstance)
+
+	ec.CWD = deps.cwd
+	ec.Model = deps.modelName
+	ec.Interactive = deps.interactive
+
+	ec.PrintBlock = func(opts extensions.PrintBlockOpts) {
+		appInstance.PrintBlockFromExtension(opts)
+	}
+	ec.SendMessage = func(text string) { appInstance.Run(text) }
+	ec.CancelAndSend = func(text string) { appInstance.InterruptAndSend(text) }
+	ec.Abort = func() { appInstance.Abort() }
+	ec.IsIdle = func() bool { return !appInstance.IsBusy() }
+	ec.Compact = func(cfg extensions.CompactConfig) error {
+		return appInstance.CompactAsync(cfg.CustomInstructions, cfg.OnComplete, cfg.OnError)
+	}
+	ec.SendMultimodalMessage = func(text string, files []extensions.FilePart) {
+		parts := make([]kit.LLMFilePart, len(files))
+		for i, f := range files {
+			parts[i] = kit.LLMFilePart{
+				Filename:  f.Filename,
+				Data:      f.Data,
+				MediaType: f.MediaType,
+			}
+		}
+		appInstance.RunWithFiles(text, parts)
+	}
+	ec.GetSessionUsage = func() extensions.SessionUsage {
+		if usageTracker == nil {
+			return extensions.SessionUsage{}
+		}
+		stats := usageTracker.GetSessionStats()
+		return extensions.SessionUsage{
+			TotalInputTokens:      stats.TotalInputTokens,
+			TotalOutputTokens:     stats.TotalOutputTokens,
+			TotalCacheReadTokens:  stats.TotalCacheReadTokens,
+			TotalCacheWriteTokens: stats.TotalCacheWriteTokens,
+			TotalCost:             stats.TotalCost,
+			RequestCount:          stats.RequestCount,
+		}
+	}
+	ec.Exit = func() { appInstance.QuitFromExtension() }
+
+	// TUI widgets/chrome — mutate runner state, then notify the TUI.
+	// Always use a goroutine for NotifyWidgetUpdate: prog.Send() deadlocks
+	// if called synchronously from inside BubbleTea's Update() handler.
+	// All call sites use go-routines uniformly.
+	ec.SetWidget = func(config extensions.WidgetConfig) {
+		kitInstance.Extensions().SetWidget(config)
+		go appInstance.NotifyWidgetUpdate()
+	}
+	ec.RemoveWidget = func(id string) {
+		kitInstance.Extensions().RemoveWidget(id)
+		go appInstance.NotifyWidgetUpdate()
+	}
+	ec.SetHeader = func(config extensions.HeaderFooterConfig) {
+		kitInstance.Extensions().SetHeader(config)
+		go appInstance.NotifyWidgetUpdate()
+	}
+	ec.RemoveHeader = func() {
+		kitInstance.Extensions().RemoveHeader()
+		go appInstance.NotifyWidgetUpdate()
+	}
+	ec.SetFooter = func(config extensions.HeaderFooterConfig) {
+		kitInstance.Extensions().SetFooter(config)
+		go appInstance.NotifyWidgetUpdate()
+	}
+	ec.RemoveFooter = func() {
+		kitInstance.Extensions().RemoveFooter()
+		go appInstance.NotifyWidgetUpdate()
+	}
+	ec.SetUIVisibility = func(v extensions.UIVisibility) {
+		kitInstance.Extensions().SetUIVisibility(v)
+		go appInstance.NotifyWidgetUpdate()
+	}
+	ec.SetEditor = func(config extensions.EditorConfig) {
+		kitInstance.Extensions().SetEditor(config)
+		go appInstance.NotifyWidgetUpdate()
+	}
+	ec.ResetEditor = func() {
+		kitInstance.Extensions().ResetEditor()
+		go appInstance.NotifyWidgetUpdate()
+	}
+	ec.SetEditorText = func(text string) {
+		appInstance.SetEditorTextFromExtension(text)
+	}
+	ec.SetStatus = func(key string, text string, priority int) {
+		kitInstance.Extensions().SetStatus(extensions.StatusBarEntry{
+			Key:      key,
+			Text:     text,
+			Priority: priority,
+		})
+		go appInstance.NotifyWidgetUpdate()
+	}
+	ec.RemoveStatus = func(key string) {
+		kitInstance.Extensions().RemoveStatus(key)
+		go appInstance.NotifyWidgetUpdate()
+	}
+
+	// Interactive prompts — channel-based round trips through the TUI.
+	ec.PromptSelect = func(config extensions.PromptSelectConfig) extensions.PromptSelectResult {
+		ch := make(chan app.PromptResponse, 1)
+		appInstance.SendPromptRequest(app.PromptRequestEvent{
+			PromptType: "select",
+			Message:    config.Message,
+			Options:    config.Options,
+			ResponseCh: ch,
+		})
+		resp := <-ch
+		if resp.Cancelled {
+			return extensions.PromptSelectResult{Cancelled: true}
+		}
+		return extensions.PromptSelectResult{Value: resp.Value, Index: resp.Index}
+	}
+	ec.PromptConfirm = func(config extensions.PromptConfirmConfig) extensions.PromptConfirmResult {
+		ch := make(chan app.PromptResponse, 1)
+		def := "false"
+		if config.DefaultValue {
+			def = "true"
+		}
+		appInstance.SendPromptRequest(app.PromptRequestEvent{
+			PromptType: "confirm",
+			Message:    config.Message,
+			Default:    def,
+			ResponseCh: ch,
+		})
+		resp := <-ch
+		if resp.Cancelled {
+			return extensions.PromptConfirmResult{Cancelled: true}
+		}
+		return extensions.PromptConfirmResult{Value: resp.Confirmed}
+	}
+	ec.PromptInput = func(config extensions.PromptInputConfig) extensions.PromptInputResult {
+		ch := make(chan app.PromptResponse, 1)
+		appInstance.SendPromptRequest(app.PromptRequestEvent{
+			PromptType:  "input",
+			Message:     config.Message,
+			Placeholder: config.Placeholder,
+			Default:     config.Default,
+			ResponseCh:  ch,
+		})
+		resp := <-ch
+		if resp.Cancelled {
+			return extensions.PromptInputResult{Cancelled: true}
+		}
+		return extensions.PromptInputResult{Value: resp.Value}
+	}
+	ec.ShowOverlay = func(config extensions.OverlayConfig) extensions.OverlayResult {
+		ch := make(chan app.OverlayResponse, 1)
+		appInstance.SendOverlayRequest(app.OverlayRequestEvent{
+			Title:       config.Title,
+			Content:     config.Content.Text,
+			Markdown:    config.Content.Markdown,
+			BorderColor: config.Style.BorderColor,
+			Background:  config.Style.Background,
+			Width:       config.Width,
+			MaxHeight:   config.MaxHeight,
+			Anchor:      string(config.Anchor),
+			Actions:     config.Actions,
+			ResponseCh:  ch,
+		})
+		resp := <-ch
+		if resp.Cancelled {
+			return extensions.OverlayResult{Cancelled: true, Index: -1}
+		}
+		return extensions.OverlayResult{
+			Action: resp.Action,
+			Index:  resp.Index,
+		}
+	}
+	ec.SuspendTUI = func(callback func()) error {
+		return appInstance.SuspendTUI(callback)
+	}
+
+	// TUI-aware model switch: also notifies the TUI status bar and
+	// refreshes the usage tracker for correct token counting.
+	ec.SetModel = func(modelString string) error {
+		// Capture previous model for the ModelChange event.
+		previousModel := kitInstance.Extensions().GetContext().Model
+		err := kitInstance.SetModel(context.Background(), modelString)
+		if err != nil {
+			return err
+		}
+		// Notify TUI so it updates model in status bar.
+		p, m, _ := models.ParseModelString(modelString)
+		appInstance.NotifyModelChanged(p, m)
+		// Update the context's Model field so handlers see it.
+		kitInstance.Extensions().UpdateContextModel(modelString)
+		// Fire OnModelChange event to extensions.
+		kitInstance.Extensions().EmitModelChange(modelString, previousModel, "extension")
+		// Update usage tracker with new model info for correct token counting.
+		ui.UpdateUsageTrackerForModel(usageTracker, modelString, viper.GetString("provider-api-key"))
+		return nil
+	}
+
+	ec.RenderMessage = func(rendererName, content string) {
+		renderer := kitInstance.Extensions().GetMessageRenderer(rendererName)
+		if renderer == nil || renderer.Render == nil {
+			appInstance.PrintFromExtension("", content)
+			return
+		}
+		w, _, _ := term.GetSize(int(os.Stdout.Fd()))
+		if w == 0 {
+			w = 80
+		}
+		rendered := renderer.Render(content, w)
+		appInstance.PrintFromExtension("", rendered)
+	}
+	ec.ReloadExtensions = func() error {
+		err := kitInstance.Extensions().Reload()
+		if err != nil {
+			return err
+		}
+		// Notify TUI that widgets/status/commands may have changed.
+		go appInstance.NotifyWidgetUpdate()
+		return nil
+	}
+
+	// Theme management (TUI only).
+	ec.RegisterTheme = func(name string, config extensions.ThemeColorConfig) {
+		tc := func(c extensions.ThemeColor) [2]string { return [2]string{c.Light, c.Dark} }
+		ui.RegisterThemeFromConfig(name,
+			tc(config.Primary), tc(config.Secondary),
+			tc(config.Success), tc(config.Warning),
+			tc(config.Error), tc(config.Info),
+			tc(config.Text), tc(config.Muted),
+			tc(config.VeryMuted), tc(config.Background),
+			tc(config.Border), tc(config.MutedBorder),
+			tc(config.System), tc(config.Tool),
+			tc(config.Accent), tc(config.Highlight),
+			tc(config.MdHeading), tc(config.MdLink),
+			tc(config.MdKeyword), tc(config.MdString),
+			tc(config.MdNumber), tc(config.MdComment),
+		)
+	}
+	ec.SetTheme = func(name string) error {
+		return ui.ApplyTheme(name)
+	}
+	ec.ListThemes = func() []string {
+		return ui.ListThemes()
+	}
+
+	// Skill context-injection (drives a new agent turn through the TUI).
+	ec.InjectSkillAsContext = func(skillName string) string {
+		skills := kitInstance.DiscoverSkillsForExtension()
+		for _, s := range skills {
+			if s.Name == skillName {
+				appInstance.Run(fmt.Sprintf("<skill name=%q>\n%s\n</skill>", s.Name, s.Content))
+				return ""
+			}
+		}
+		return fmt.Sprintf("skill not found: %s", skillName)
+	}
+	ec.InjectRawSkillAsContext = func(path string) string {
+		s, err := kitInstance.LoadSkillForExtension(path)
+		if err != "" {
+			return err
+		}
+		appInstance.Run(fmt.Sprintf("<skill name=%q>\n%s\n</skill>", s.Name, s.Content))
+		return ""
+	}
+
+	return ec
+}

cmd/models.go

@@ -55,7 +55,7 @@ func printAllProviders(showAll bool) error {
 	if showAll {
 		providerIDs = kit.GetSupportedProviders()
 	} else {
-		providerIDs = kit.GetFantasyProviders()
+		providerIDs = kit.GetLLMProviders()
 	}
 	sort.Strings(providerIDs)
 

cmd/setup.go

@@ -41,7 +41,6 @@ func BuildAppOptions(mcpConfig *config.Config, modelName string, serverNames, to
 		StreamingEnabled: viper.GetBool("stream"),
 		Quiet:            quietFlag,
 		Debug:            viper.GetBool("debug"),
-		CompactMode:      viper.GetBool("compact"),
 	}
 }
 
@@ -131,7 +130,6 @@ func SetupCLIForNonInteractive(k *kit.Kit) (*ui.CLI, error) {
 		Agent:          agentAdapter,
 		ModelString:    viper.GetString("model"),
 		Debug:          viper.GetBool("debug"),
-		Compact:        viper.GetBool("compact"),
 		Quiet:          quietFlag,
 		ShowDebug:      false,
 		ProviderAPIKey: viper.GetString("provider-api-key"),

examples/extensions/README.md

@@ -58,6 +58,7 @@ kit install github.com/mark3labs/kit/examples/extensions --local
 | `project-rules.go` | Project-specific rules | Session data, file reading |
 | `protected-paths.go` | Block dangerous operations | `OnToolCall` with blocking |
 | `permission-gate.go` | Confirm destructive actions | `OnToolCall` with confirmation |
+| `usage-budget.go` | Soft cost cap + per-turn report | `OnLLMUsage`, `SetState`/`GetState`, enriched `AgentEndEvent` |
 
 ### Tools & Commands
 

examples/extensions/all_extensions_load_test.go

@@ -0,0 +1,27 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/mark3labs/kit/pkg/extensions/test"
+)
+
+// TestAllExtensions_Load is a smoke test that verifies every single-file
+// example extension in this directory can be loaded by the Yaegi interpreter
+// without errors. This catches syntax errors, missing symbols, bad imports,
+// and Init signature mismatches.
+func TestAllExtensions_Load(t *testing.T) {
+	files := extensionFiles(t)
+
+	for _, file := range files {
+		t.Run(file, func(t *testing.T) {
+			harness := test.New(t)
+			ext := harness.LoadFile(file)
+			if ext == nil {
+				t.Fatalf("%s: extension should not be nil after loading", file)
+			}
+		})
+	}
+
+	t.Logf("successfully loaded %d extensions", len(files))
+}

examples/extensions/all_extensions_sanity_test.go

@@ -0,0 +1,253 @@
+package main
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/mark3labs/kit/internal/extensions"
+	"github.com/mark3labs/kit/pkg/extensions/test"
+)
+
+// extensionFiles returns all single-file extensions in the current directory.
+// It skips test files, the test template, and files without an Init function.
+func extensionFiles(t *testing.T) []string {
+	t.Helper()
+
+	skip := map[string]bool{
+		"extension_test_template.go": true,
+	}
+
+	entries, err := os.ReadDir(".")
+	if err != nil {
+		t.Fatalf("failed to read directory: %v", err)
+	}
+
+	var files []string
+	for _, entry := range entries {
+		name := entry.Name()
+		if entry.IsDir() || filepath.Ext(name) != ".go" {
+			continue
+		}
+		if strings.HasSuffix(name, "_test.go") || skip[name] {
+			continue
+		}
+		src, err := os.ReadFile(name)
+		if err != nil {
+			t.Fatalf("failed to read %s: %v", name, err)
+		}
+		if !strings.Contains(string(src), "func Init(") {
+			continue
+		}
+		files = append(files, name)
+	}
+
+	if len(files) == 0 {
+		t.Fatal("no extensions found — check the directory")
+	}
+	return files
+}
+
+// TestAllExtensions_Lifecycle verifies that every extension survives a full
+// SessionStart → SessionShutdown round-trip without errors.
+func TestAllExtensions_Lifecycle(t *testing.T) {
+	for _, file := range extensionFiles(t) {
+		t.Run(file, func(t *testing.T) {
+			harness := test.New(t)
+			harness.LoadFile(file)
+
+			_, err := harness.Emit(extensions.SessionStartEvent{
+				SessionID: "smoke-test-session",
+			})
+			if err != nil {
+				t.Fatalf("SessionStart error: %v", err)
+			}
+
+			_, err = harness.Emit(extensions.SessionShutdownEvent{})
+			if err != nil {
+				t.Fatalf("SessionShutdown error: %v", err)
+			}
+		})
+	}
+}
+
+// TestAllExtensions_CommandSanity checks that every registered command has
+// a non-empty name, a non-empty description, no spaces in the name, no
+// leading slash, a non-nil Execute function, and no duplicate names.
+func TestAllExtensions_CommandSanity(t *testing.T) {
+	for _, file := range extensionFiles(t) {
+		t.Run(file, func(t *testing.T) {
+			harness := test.New(t)
+			harness.LoadFile(file)
+
+			cmds := harness.RegisteredCommands()
+			seen := make(map[string]bool)
+			for _, cmd := range cmds {
+				if cmd.Name == "" {
+					t.Error("command has empty name")
+				}
+				if strings.Contains(cmd.Name, " ") {
+					t.Errorf("command %q contains spaces", cmd.Name)
+				}
+				if strings.HasPrefix(cmd.Name, "/") {
+					t.Errorf("command %q has leading slash (framework adds it)", cmd.Name)
+				}
+				if cmd.Description == "" {
+					t.Errorf("command %q has empty description", cmd.Name)
+				}
+				if cmd.Execute == nil {
+					t.Errorf("command %q has nil Execute function", cmd.Name)
+				}
+				if seen[cmd.Name] {
+					t.Errorf("duplicate command name %q", cmd.Name)
+				}
+				seen[cmd.Name] = true
+			}
+		})
+	}
+}
+
+// TestAllExtensions_ToolSanity checks that every registered tool has a
+// non-empty name, a non-empty description, at least one executor, valid
+// JSON in its Parameters field, and no duplicate names.
+func TestAllExtensions_ToolSanity(t *testing.T) {
+	for _, file := range extensionFiles(t) {
+		t.Run(file, func(t *testing.T) {
+			harness := test.New(t)
+			harness.LoadFile(file)
+
+			tools := harness.RegisteredTools()
+			seen := make(map[string]bool)
+			for _, tool := range tools {
+				if tool.Name == "" {
+					t.Error("tool has empty name")
+				}
+				if tool.Description == "" {
+					t.Errorf("tool %q has empty description", tool.Name)
+				}
+				if tool.Execute == nil && tool.ExecuteWithContext == nil {
+					t.Errorf("tool %q has no executor (both Execute and ExecuteWithContext are nil)", tool.Name)
+				}
+				if tool.Parameters != "" && !json.Valid([]byte(tool.Parameters)) {
+					t.Errorf("tool %q has invalid JSON in Parameters: %s", tool.Name, tool.Parameters)
+				}
+				if seen[tool.Name] {
+					t.Errorf("duplicate tool name %q", tool.Name)
+				}
+				seen[tool.Name] = true
+			}
+		})
+	}
+}
+
+// TestAllExtensions_ZeroValueEvents fires every event type (as zero-value
+// structs) at each extension and verifies no errors are returned. Extensions
+// should be resilient to events they don't handle and to events with empty
+// fields.
+func TestAllExtensions_ZeroValueEvents(t *testing.T) {
+	// Build the set of zero-value events for every event type.
+	zeroEvents := []extensions.Event{
+		extensions.ToolCallEvent{},
+		extensions.ToolExecutionStartEvent{},
+		extensions.ToolExecutionEndEvent{},
+		extensions.ToolOutputEvent{},
+		extensions.ToolResultEvent{},
+		extensions.InputEvent{},
+		extensions.BeforeAgentStartEvent{},
+		extensions.AgentStartEvent{},
+		extensions.AgentEndEvent{},
+		extensions.MessageStartEvent{},
+		extensions.MessageUpdateEvent{},
+		extensions.MessageEndEvent{},
+		extensions.SessionStartEvent{},
+		extensions.SessionShutdownEvent{},
+		extensions.ModelChangeEvent{},
+		extensions.ContextPrepareEvent{},
+		extensions.BeforeForkEvent{},
+		extensions.BeforeSessionSwitchEvent{},
+		extensions.BeforeCompactEvent{},
+		extensions.SubagentStartEvent{},
+		extensions.SubagentChunkEvent{},
+		extensions.SubagentEndEvent{},
+	}
+
+	for _, file := range extensionFiles(t) {
+		t.Run(file, func(t *testing.T) {
+			harness := test.New(t)
+			harness.LoadFile(file)
+
+			for _, ev := range zeroEvents {
+				_, err := harness.Emit(ev)
+				if err != nil {
+					t.Errorf("event %T returned error: %v", ev, err)
+				}
+			}
+		})
+	}
+}
+
+// TestAllExtensions_WidgetSanity emits SessionStart and then checks that
+// any widgets set during initialization have non-empty IDs and valid
+// placements.
+func TestAllExtensions_WidgetSanity(t *testing.T) {
+	validPlacements := map[extensions.WidgetPlacement]bool{
+		"above": true,
+		"below": true,
+	}
+
+	for _, file := range extensionFiles(t) {
+		t.Run(file, func(t *testing.T) {
+			harness := test.New(t)
+			harness.LoadFile(file)
+
+			// Trigger SessionStart so extensions that set widgets on init do so.
+			_, _ = harness.Emit(extensions.SessionStartEvent{
+				SessionID: "widget-sanity-test",
+			})
+
+			// Widgets is an exported field on MockContext; reads are safe
+			// here because Emit returned synchronously.
+			for id, w := range harness.Context().Widgets {
+				if w.ID == "" {
+					t.Errorf("widget stored with key %q has empty ID", id)
+				}
+				if w.ID != id {
+					t.Errorf("widget key %q doesn't match widget ID %q", id, w.ID)
+				}
+				if !validPlacements[w.Placement] {
+					t.Errorf("widget %q has invalid placement %q (want \"above\" or \"below\")", id, w.Placement)
+				}
+			}
+		})
+	}
+}
+
+// TestAllExtensions_IdempotentLifecycle verifies that receiving SessionStart
+// twice and SessionShutdown twice doesn't cause errors — extensions should
+// be defensive about repeated lifecycle events.
+func TestAllExtensions_IdempotentLifecycle(t *testing.T) {
+	for _, file := range extensionFiles(t) {
+		t.Run(file, func(t *testing.T) {
+			harness := test.New(t)
+			harness.LoadFile(file)
+
+			for i := range 2 {
+				_, err := harness.Emit(extensions.SessionStartEvent{
+					SessionID: "idempotent-test",
+				})
+				if err != nil {
+					t.Fatalf("SessionStart #%d error: %v", i+1, err)
+				}
+			}
+
+			for i := range 2 {
+				_, err := harness.Emit(extensions.SessionShutdownEvent{})
+				if err != nil {
+					t.Fatalf("SessionShutdown #%d error: %v", i+1, err)
+				}
+			}
+		})
+	}
+}

examples/extensions/bridge_demo.go

@@ -0,0 +1,170 @@
+//go:build ignore
+
+// bridge_demo.go - Demonstrates the new bridged SDK APIs for extensions.
+// This extension showcases tree navigation, skill loading, template parsing,
+// and model resolution capabilities.
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"strings"
+
+	"kit/ext"
+)
+
+var (
+	discoveredSkills []ext.Skill
+	currentBranch    []ext.TreeNode
+)
+
+func Init(api ext.API) {
+	// Register /tree-info command to demonstrate tree navigation
+	api.RegisterCommand(ext.CommandDef{
+		Name:        "tree-info",
+		Description: "Show current conversation tree information",
+		Execute: func(args string, ctx ext.Context) (string, error) {
+			branch := ctx.GetCurrentBranch()
+			info := fmt.Sprintf("Current branch has %d nodes:\n", len(branch))
+			for i, node := range branch {
+				info += fmt.Sprintf("  [%d] %s (%s): %s...\n", i, node.Type, node.ID[:8], truncate(node.Content, 40))
+			}
+			ctx.PrintInfo(info)
+			return "", nil
+		},
+	})
+
+	// Register /discover-skills command
+	api.RegisterCommand(ext.CommandDef{
+		Name:        "discover-skills",
+		Description: "Discover and list available skills",
+		Execute: func(args string, ctx ext.Context) (string, error) {
+			result := ctx.DiscoverSkills()
+			if result.Error != "" {
+				return "", fmt.Errorf("discovery failed: %s", result.Error)
+			}
+			discoveredSkills = result.Skills
+
+			info := fmt.Sprintf("Discovered %d skills:\n", len(result.Skills))
+			for _, s := range result.Skills {
+				info += fmt.Sprintf("  - %s: %s\n", s.Name, s.Description)
+			}
+			ctx.PrintInfo(info)
+			return "", nil
+		},
+	})
+
+	// Register /parse-template command
+	api.RegisterCommand(ext.CommandDef{
+		Name:        "parse-template",
+		Description: "Parse a template and show extracted variables",
+		Execute: func(args string, ctx ext.Context) (string, error) {
+			if args == "" {
+				args = "Hello {{name}}, welcome to {{place}}!"
+			}
+			tpl := ctx.ParseTemplate("demo", args)
+			info := fmt.Sprintf("Template: %s\nVariables: %v", tpl.Content, tpl.Variables)
+			ctx.PrintInfo(info)
+			return "", nil
+		},
+	})
+
+	// Register /render-template command
+	api.RegisterCommand(ext.CommandDef{
+		Name:        "render-template",
+		Description: "Render a template with variables (usage: /render-template name=John place=Kit)",
+		Execute: func(args string, ctx ext.Context) (string, error) {
+			tpl := ctx.ParseTemplate("demo", "Hello {{name}}, welcome to {{place}}!")
+			vars := ctx.ParseArguments(args, ext.ArgumentPattern{
+				Flags: map[string]string{"name": "name", "place": "place"},
+			})
+			rendered := ctx.RenderTemplate(tpl, vars.Vars)
+			ctx.PrintInfo("Rendered: " + rendered)
+			return "", nil
+		},
+	})
+
+	// Register /check-model command
+	api.RegisterCommand(ext.CommandDef{
+		Name:        "check-model",
+		Description: "Check model capabilities and availability",
+		Execute: func(args string, ctx ext.Context) (string, error) {
+			model := args
+			if model == "" {
+				model = ctx.Model
+			}
+
+			available := ctx.CheckModelAvailable(model)
+			caps, err := ctx.GetModelCapabilities(model)
+
+			info := fmt.Sprintf("Model: %s\n", model)
+			info += fmt.Sprintf("Available: %v\n", available)
+			if err == "" {
+				info += fmt.Sprintf("Provider: %s\n", caps.Provider)
+				info += fmt.Sprintf("Context Limit: %d\n", caps.ContextLimit)
+				info += fmt.Sprintf("Reasoning: %v\n", caps.Reasoning)
+			} else {
+				info += fmt.Sprintf("Error: %s\n", err)
+			}
+			ctx.PrintInfo(info)
+			return "", nil
+		},
+	})
+
+	// Register /resolve-chain command
+	api.RegisterCommand(ext.CommandDef{
+		Name:        "resolve-chain",
+		Description: "Resolve a model chain (usage: /resolve-chain claude-opus,gpt-4o,claude-sonnet)",
+		Execute: func(args string, ctx ext.Context) (string, error) {
+			if args == "" {
+				args = "anthropic/claude-opus-4,anthropic/claude-sonnet-4,openai/gpt-4o"
+			}
+			prefs := ctx.SimpleParseArguments(args, 1)
+			chain := []string{}
+			if len(prefs) > 1 {
+				// Split the first arg by comma
+				for _, p := range strings.Split(prefs[1], ",") {
+					p = strings.TrimSpace(p)
+					if p != "" {
+						chain = append(chain, p)
+					}
+				}
+			}
+
+			result := ctx.ResolveModelChain(chain)
+			info, _ := json.MarshalIndent(result, "", "  ")
+			ctx.PrintInfo("Resolution Result:\n" + string(info))
+			return "", nil
+		},
+	})
+
+	// Register /test-conditional command
+	api.RegisterCommand(ext.CommandDef{
+		Name:        "test-conditional",
+		Description: "Test model conditional rendering",
+		Execute: func(args string, ctx ext.Context) (string, error) {
+			content := `<if-model is="claude-*">This is for Claude models<else>This is for other models</if-model>`
+			rendered := ctx.RenderWithModelConditionals(content)
+			ctx.PrintInfo("Input: " + content)
+			ctx.PrintInfo("Output: " + rendered)
+			ctx.PrintInfo(fmt.Sprintf("Current model matches 'claude-*': %v", ctx.EvaluateModelConditional("claude-*")))
+			return "", nil
+		},
+	})
+
+	// OnSessionStart: discover skills automatically
+	api.OnSessionStart(func(e ext.SessionStartEvent, ctx ext.Context) {
+		result := ctx.DiscoverSkills()
+		if result.Error == "" && len(result.Skills) > 0 {
+			discoveredSkills = result.Skills
+			ctx.SetStatus("bridge-demo", fmt.Sprintf("%d skills", len(result.Skills)), 50)
+		}
+	})
+}
+
+func truncate(s string, max int) string {
+	if len(s) <= max {
+		return s
+	}
+	return s[:max-3] + "..."
+}

examples/extensions/conversation-manager.go

@@ -0,0 +1,406 @@
+//go:build ignore
+
+// conversation-manager.go - Advanced conversation tree navigation and management.
+// This extension demonstrates:
+// - Tree navigation (GetTreeNode, GetCurrentBranch, NavigateTo)
+// - Branch summarization and collapsing
+// - Interactive tree exploration
+//
+// Commands:
+//   /tree              - Show conversation tree structure
+//   /branch            - Show current branch path
+//   /goto <entry-id>   - Navigate to a specific entry
+//   /summarize <n>     - Summarize last N messages
+//   /fresh-context     - Collapse branch and start fresh
+//   /loop <n> <prompt> - Execute prompt N times with fresh context each iteration
+
+package main
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+
+	"kit/ext"
+)
+
+var (
+	loopActive    bool
+	loopCount     int
+	loopCurrent   int
+	loopPrompt    string
+	loopStartNode string
+)
+
+func Init(api ext.API) {
+	// /tree - Show tree structure
+	api.RegisterCommand(ext.CommandDef{
+		Name:        "tree",
+		Description: "Show conversation tree structure",
+		Execute: func(args string, ctx ext.Context) (string, error) {
+			showTree(ctx)
+			return "", nil
+		},
+	})
+
+	// /branch - Show current branch
+	api.RegisterCommand(ext.CommandDef{
+		Name:        "branch",
+		Description: "Show current conversation branch",
+		Execute: func(args string, ctx ext.Context) (string, error) {
+			showBranch(ctx)
+			return "", nil
+		},
+	})
+
+	// /goto - Navigate to entry
+	api.RegisterCommand(ext.CommandDef{
+		Name:        "goto",
+		Description: "Navigate to a specific entry ID (usage: /goto <entry-id>)",
+		Execute: func(args string, ctx ext.Context) (string, error) {
+			if args == "" {
+				ctx.PrintError("Usage: /goto <entry-id>")
+				return "", nil
+			}
+			result := ctx.NavigateTo(args)
+			if !result.Success {
+				ctx.PrintError(fmt.Sprintf("Navigation failed: %s", result.Error))
+				return "", nil
+			}
+			ctx.PrintInfo(fmt.Sprintf("Navigated to entry: %s", args))
+
+			// Show the node we navigated to
+			node := ctx.GetTreeNode(args)
+			if node != nil {
+				ctx.PrintInfo(fmt.Sprintf("Entry type: %s, Role: %s", node.Type, node.Role))
+			}
+			return "", nil
+		},
+	})
+
+	// /summarize - Summarize recent messages
+	api.RegisterCommand(ext.CommandDef{
+		Name:        "summarize",
+		Description: "Summarize last N messages (usage: /summarize [n=5])",
+		Execute: func(args string, ctx ext.Context) (string, error) {
+			n := 5
+			if args != "" {
+				if parsed, err := strconv.Atoi(args); err == nil && parsed > 0 {
+					n = parsed
+				}
+			}
+
+			branch := ctx.GetCurrentBranch()
+			if len(branch) < 2 {
+				ctx.PrintError("Not enough messages to summarize")
+				return "", nil
+			}
+
+			// Find range to summarize
+			startIdx := len(branch) - n - 1
+			if startIdx < 0 {
+				startIdx = 0
+			}
+			endIdx := len(branch) - 1
+
+			fromID := branch[startIdx].ID
+			toID := branch[endIdx].ID
+
+			ctx.PrintInfo(fmt.Sprintf("Summarizing messages %d to %d...", startIdx, endIdx))
+			summary := ctx.SummarizeBranch(fromID, toID)
+
+			if summary == "" {
+				ctx.PrintError("Failed to generate summary")
+				return "", nil
+			}
+
+			ctx.PrintBlock(ext.PrintBlockOpts{
+				Text:        summary,
+				BorderColor: "#89b4fa",
+				Subtitle:    "conversation-manager · Summary",
+			})
+			return "", nil
+		},
+	})
+
+	// /fresh-context - Collapse and restart
+	api.RegisterCommand(ext.CommandDef{
+		Name:        "fresh-context",
+		Description: "Collapse conversation to summary and start fresh",
+		Execute: func(args string, ctx ext.Context) (string, error) {
+			branch := ctx.GetCurrentBranch()
+			if len(branch) < 3 {
+				ctx.PrintError("Not enough context to collapse")
+				return "", nil
+			}
+
+			// Keep first message (system), summarize rest
+			fromID := branch[1].ID
+			toID := branch[len(branch)-1].ID
+
+			ctx.PrintInfo("Generating summary for context collapse...")
+			summary := ctx.SummarizeBranch(fromID, toID)
+
+			if summary == "" {
+				ctx.PrintError("Failed to generate summary")
+				return "", nil
+			}
+
+			// Collapse the branch
+			result := ctx.CollapseBranch(fromID, toID, summary)
+			if !result.Success {
+				ctx.PrintError(fmt.Sprintf("Collapse failed: %s", result.Error))
+				return "", nil
+			}
+
+			ctx.PrintInfo("Context collapsed. Starting fresh with summary.")
+			ctx.PrintBlock(ext.PrintBlockOpts{
+				Text:        summary,
+				BorderColor: "#a6e3a1",
+				Subtitle:    "conversation-manager · Collapsed Context",
+			})
+
+			// Set a widget showing we're in fresh mode
+			ctx.SetWidget(ext.WidgetConfig{
+				ID:        "fresh-context",
+				Placement: ext.WidgetAbove,
+				Content:   ext.WidgetContent{Text: "🌱 Fresh Context Mode - Previous conversation collapsed"},
+				Style:     ext.WidgetStyle{BorderColor: "#a6e3a1"},
+			})
+
+			return "", nil
+		},
+	})
+
+	// /loop - Execute with fresh context each iteration
+	api.RegisterCommand(ext.CommandDef{
+		Name:        "loop",
+		Description: "Execute prompt N times with fresh context (usage: /loop 5 analyze this code)",
+		Execute: func(args string, ctx ext.Context) (string, error) {
+			if loopActive {
+				ctx.PrintError("Loop already in progress. Wait for completion.")
+				return "", nil
+			}
+
+			// Parse arguments
+			parts := strings.SplitN(args, " ", 2)
+			if len(parts) < 2 {
+				ctx.PrintError("Usage: /loop <count> <prompt>")
+				return "", nil
+			}
+
+			count, err := strconv.Atoi(parts[0])
+			if err != nil || count <= 0 || count > 10 {
+				ctx.PrintError("Invalid count (must be 1-10)")
+				return "", nil
+			}
+
+			loopCount = count
+			loopCurrent = 0
+			loopPrompt = parts[1]
+			loopActive = true
+
+			// Store current branch position
+			branch := ctx.GetCurrentBranch()
+			if len(branch) > 0 {
+				loopStartNode = branch[len(branch)-1].ID
+			}
+
+			ctx.PrintInfo(fmt.Sprintf("Starting loop: %d iterations", loopCount))
+			ctx.SetWidget(ext.WidgetConfig{
+				ID:        "loop-progress",
+				Placement: ext.WidgetAbove,
+				Content:   ext.WidgetContent{Text: fmt.Sprintf("🔄 Loop: 0/%d - %s", loopCount, loopPrompt)},
+				Style:     ext.WidgetStyle{BorderColor: "#fab387"},
+			})
+
+			// Start first iteration
+			executeLoopIteration(ctx)
+			return "", nil
+		},
+	})
+
+	// OnAgentEnd handles loop continuation
+	api.OnAgentEnd(func(e ext.AgentEndEvent, ctx ext.Context) {
+		if !loopActive {
+			return
+		}
+
+		loopCurrent++
+
+		if loopCurrent >= loopCount {
+			// Loop complete
+			loopActive = false
+			ctx.RemoveWidget("loop-progress")
+			ctx.PrintInfo(fmt.Sprintf("✅ Loop complete: %d/%d iterations", loopCurrent, loopCount))
+
+			// Show final summary
+			branch := ctx.GetCurrentBranch()
+			if len(branch) > 0 && loopStartNode != "" {
+				summary := ctx.SummarizeBranch(loopStartNode, branch[len(branch)-1].ID)
+				if summary != "" {
+					ctx.PrintBlock(ext.PrintBlockOpts{
+						Text:        summary,
+						BorderColor: "#a6e3a1",
+						Subtitle:    "conversation-manager · Loop Summary",
+					})
+				}
+			}
+			return
+		}
+
+		// Update progress
+		ctx.SetWidget(ext.WidgetConfig{
+			ID:        "loop-progress",
+			Placement: ext.WidgetAbove,
+			Content:   ext.WidgetContent{Text: fmt.Sprintf("🔄 Loop: %d/%d - %s", loopCurrent, loopCount, loopPrompt)},
+			Style:     ext.WidgetStyle{BorderColor: "#fab387"},
+		})
+
+		// Collapse previous iteration for fresh context
+		branch := ctx.GetCurrentBranch()
+		if len(branch) >= 2 {
+			// Find the user messages (look for the one before the last assistant message)
+			// We want to collapse from the user message that started this iteration
+			// to the last assistant response
+			var collapseStartIdx = -1
+			for i := len(branch) - 1; i >= 0; i-- {
+				if branch[i].Role == "assistant" {
+					// Found the last assistant message, now find the user message before it
+					for j := i - 1; j >= 0; j-- {
+						if branch[j].Role == "user" {
+							collapseStartIdx = j
+							break
+						}
+					}
+					break
+				}
+			}
+
+			if collapseStartIdx >= 0 {
+				fromID := branch[collapseStartIdx].ID
+				toID := branch[len(branch)-1].ID
+
+				ctx.PrintInfo(fmt.Sprintf("Collapsing iteration %d for fresh context...", loopCurrent))
+				summary := ctx.SummarizeBranch(fromID, toID)
+				if summary != "" {
+					result := ctx.CollapseBranch(fromID, toID, summary)
+					if result.Success {
+						ctx.PrintInfo("Context collapsed successfully")
+					} else {
+						ctx.PrintError(fmt.Sprintf("Collapse failed: %s", result.Error))
+					}
+				}
+			}
+		}
+
+		// Small delay to let UI update
+		time.Sleep(500 * time.Millisecond)
+
+		// Trigger next iteration
+		executeLoopIteration(ctx)
+	})
+}
+
+// showTree displays the conversation tree structure
+func showTree(ctx ext.Context) {
+	branch := ctx.GetCurrentBranch()
+	if len(branch) == 0 {
+		ctx.PrintInfo("Tree is empty")
+		return
+	}
+
+	var output strings.Builder
+	output.WriteString(fmt.Sprintf("Conversation Tree (%d nodes):\n\n", len(branch)))
+
+	for i, node := range branch {
+		prefix := "  "
+		if i == len(branch)-1 {
+			prefix = "▶ " // Current node
+		} else {
+			prefix = "  "
+		}
+
+		roleIcon := "💬"
+		switch node.Role {
+		case "user":
+			roleIcon = "👤"
+		case "assistant":
+			roleIcon = "🤖"
+		case "system":
+			roleIcon = "⚙️"
+		}
+
+		content := truncate(node.Content, 50)
+		if node.Type == "branch_summary" {
+			roleIcon = "📋"
+			content = "[Summary] " + truncate(node.Content, 40)
+		}
+
+		output.WriteString(fmt.Sprintf("%s%s %s: %s (%s...)\n", prefix, roleIcon, node.Role, node.ID[:8], content))
+
+		// Show children count if any
+		children := ctx.GetChildren(node.ID)
+		if len(children) > 0 {
+			output.WriteString(fmt.Sprintf("    └─ %d branch(es)\n", len(children)))
+		}
+	}
+
+	ctx.PrintBlock(ext.PrintBlockOpts{
+		Text:        output.String(),
+		BorderColor: "#89b4fa",
+		Subtitle:    "conversation-manager · Tree View",
+	})
+}
+
+// showBranch displays the current branch path
+func showBranch(ctx ext.Context) {
+	branch := ctx.GetCurrentBranch()
+	if len(branch) == 0 {
+		ctx.PrintInfo("No active branch")
+		return
+	}
+
+	var output strings.Builder
+	output.WriteString(fmt.Sprintf("Current Branch (%d nodes from root to leaf):\n\n", len(branch)))
+
+	for i, node := range branch {
+		marker := "  "
+		if i == len(branch)-1 {
+			marker = "▶ " // Current leaf
+		}
+
+		output.WriteString(fmt.Sprintf("%s[%d] %s (%s): %s\n",
+			marker, i, node.Type, node.ID[:8], truncate(node.Content, 40)))
+	}
+
+	// Show current node details
+	leaf := branch[len(branch)-1]
+	output.WriteString(fmt.Sprintf("\nCurrent Leaf:\n"))
+	output.WriteString(fmt.Sprintf("  ID: %s\n", leaf.ID))
+	output.WriteString(fmt.Sprintf("  Type: %s\n", leaf.Type))
+	output.WriteString(fmt.Sprintf("  Role: %s\n", leaf.Role))
+	output.WriteString(fmt.Sprintf("  Model: %s\n", leaf.Model))
+	output.WriteString(fmt.Sprintf("  Children: %d\n", len(leaf.Children)))
+
+	ctx.PrintBlock(ext.PrintBlockOpts{
+		Text:        output.String(),
+		BorderColor: "#cba6f7",
+		Subtitle:    "conversation-manager · Branch View",
+	})
+}
+
+// executeLoopIteration triggers the next loop iteration
+func executeLoopIteration(ctx ext.Context) {
+	iterationPrompt := fmt.Sprintf("[%d/%d] %s", loopCurrent+1, loopCount, loopPrompt)
+	ctx.SendMessage(iterationPrompt)
+}
+
+// truncate helper
+func truncate(s string, max int) string {
+	if len(s) <= max {
+		return s
+	}
+	return s[:max-3] + "..."
+}

examples/extensions/dev-reload.go

@@ -7,10 +7,12 @@
 // development: edit your extension source, then type /reload to pick up
 // changes immediately.
 //
-// Event handlers, slash commands, tool renderers, message renderers, and
-// keyboard shortcuts update immediately. Extension-defined tools are NOT
-// updated (they are baked into the agent at creation time and require a
-// restart).
+// Note: Extensions in autoloaded directories (~/.config/kit/extensions/
+// and .kit/extensions/) are automatically reloaded on save. The /reload
+// command is useful for extensions loaded via -e from other locations.
+//
+// Event handlers, slash commands, tool definitions, tool renderers,
+// message renderers, and keyboard shortcuts all update immediately.
 //
 // Commands:
 //   /reload   — hot-reload all extensions from disk

examples/extensions/inline-bash.go

@@ -10,13 +10,21 @@ import (
 	"kit/ext"
 )
 
+// re matches !{...} with non-greedy content.
+var re = regexp.MustCompile(`!\{([^}]+)\}`)
+
 // Init expands inline bash expressions in user prompts before they reach the
-// LLM. Text like !{git branch --show-current} is replaced with the command's
-// stdout.
+// LLM. Text like !{git rev-parse --abbrev-ref HEAD} is replaced with the
+// command's stdout.
+//
+// In interactive mode the expansion happens at submit time via an editor
+// interceptor, so the expanded text is also visible in the user message
+// block on screen. In non-interactive mode (CLI, script, queue) the
+// expansion happens via OnInput transform.
 //
 // Examples:
 //
-//	"Fix the tests on !{git branch --show-current}"
+//	"Fix the tests on !{git rev-parse --abbrev-ref HEAD}"
 //	  → "Fix the tests on main"
 //
 //	"The current directory is !{pwd}"
@@ -24,29 +32,59 @@ import (
 //
 // Usage: kit -e examples/extensions/inline-bash.go
 func Init(api ext.API) {
-	// Matches !{...} with non-greedy content.
-	re := regexp.MustCompile(`!\{([^}]+)\}`)
+	// ── Interactive mode: editor interceptor ──────────────────────────
+	// Intercept Enter / Ctrl+D so we can expand !{...} BEFORE the
+	// SubmitMsg is created. This ensures the expanded text appears in
+	// the user message block on screen as well as in the LLM prompt.
+	api.OnSessionStart(func(_ ext.SessionStartEvent, ctx ext.Context) {
+		if !ctx.Interactive {
+			return
+		}
+		ctx.SetEditor(ext.EditorConfig{
+			HandleKey: func(key string, currentText string) ext.EditorKeyAction {
+				if (key == "enter" || key == "ctrl+d") && re.MatchString(currentText) {
+					expanded := expand(currentText)
+					// Clear the textarea asynchronously — calling
+					// SetEditorText synchronously from inside Update()
+					// would deadlock the BubbleTea event loop.
+					go ctx.SetEditorText("")
+					return ext.EditorKeyAction{
+						Type:       ext.EditorKeySubmit,
+						SubmitText: expanded,
+					}
+				}
+				return ext.EditorKeyAction{Type: ext.EditorKeyPassthrough}
+			},
+		})
+	})
 
+	// ── Non-interactive fallback: OnInput transform ──────────────────
+	// For CLI, script, and queue sources the editor interceptor is not
+	// active, so we fall back to OnInput which still rewrites the
+	// prompt text sent to the LLM.
 	api.OnInput(func(ev ext.InputEvent, ctx ext.Context) *ext.InputResult {
-		if !re.MatchString(ev.Text) {
+		if ev.Source == "interactive" || !re.MatchString(ev.Text) {
 			return nil
 		}
 
-		expanded := re.ReplaceAllStringFunc(ev.Text, func(match string) string {
-			// Extract the command between !{ and }.
-			cmd := re.FindStringSubmatch(match)[1]
-			cmd = strings.TrimSpace(cmd)
-
-			out, err := exec.Command("bash", "-c", cmd).Output()
-			if err != nil {
-				return match // keep original on error
-			}
-			return strings.TrimSpace(string(out))
-		})
-
 		return &ext.InputResult{
 			Action: "transform",
-			Text:   expanded,
+			Text:   expand(ev.Text),
 		}
 	})
 }
+
+// expand replaces every !{cmd} in text with the command's stdout.
+// On error the original !{cmd} token is preserved.
+func expand(text string) string {
+	return re.ReplaceAllStringFunc(text, func(match string) string {
+		cmd := re.FindStringSubmatch(match)[1]
+		cmd = strings.TrimSpace(cmd)
+
+		out, err := exec.Command("bash", "-c", cmd).Output()
+		if err != nil {
+			return match // keep original on error
+		}
+		return strings.TrimSpace(string(out))
+	})
+}

examples/extensions/kit-telegram/main.go

@@ -168,6 +168,10 @@ var (
 	// Test
 	pendingTest *PendingTest
 
+	// Typing indicator
+	typingTicker *time.Ticker
+	typingStop   chan struct{}
+
 	// Latest context for background goroutines
 	latestCtx    ext.Context
 	latestCtxSet bool
@@ -203,8 +207,23 @@ func configDir() string {
 	return filepath.Join(home, ".config", "kit")
 }
 
+func globalConfigDir() string {
+	home, _ := os.UserHomeDir()
+	return filepath.Join(home, ".config", "kit")
+}
+
 func configPath() string {
-	return filepath.Join(configDir(), "kit-telegram.json")
+	// Prefer project-local config, fall back to global config.
+	local := filepath.Join(configDir(), "kit-telegram.json")
+	if _, err := os.Stat(local); err == nil {
+		return local
+	}
+	global := filepath.Join(globalConfigDir(), "kit-telegram.json")
+	if _, err := os.Stat(global); err == nil {
+		return global
+	}
+	// Neither exists — return local path (will be created on connect).
+	return local
 }
 
 func failureLogDir() string {
@@ -387,6 +406,14 @@ func tgEditMessageText(token string, chatID int64, messageID int, text string) (
 	return &msg, nil
 }
 
+func tgSendChatAction(token string, chatID int64, action string) error {
+	_, err := telegramRequest(token, "sendChatAction", map[string]any{
+		"chat_id": chatID,
+		"action":  action,
+	}, 15)
+	return err
+}
+
 // ──────────────────────────────────────────────
 // Error classification
 // ──────────────────────────────────────────────
@@ -637,6 +664,48 @@ func clearHealthTimer() {
 	}
 }
 
+// ──────────────────────────────────────────────
+// Typing indicator
+// ──────────────────────────────────────────────
+
+func startTypingLoop() {
+	mu.Lock()
+	defer mu.Unlock()
+	if typingTicker != nil {
+		return
+	}
+	cfg := config
+	if cfg == nil || !cfg.Enabled {
+		return
+	}
+	token := cfg.BotToken
+	chatID := cfg.ChatID
+	typingTicker = time.NewTicker(4 * time.Second)
+	typingStop = make(chan struct{})
+	// Send immediately, then every 4 seconds.
+	go func() {
+		tgSendChatAction(token, chatID, "typing")
+		for {
+			select {
+			case <-typingTicker.C:
+				tgSendChatAction(token, chatID, "typing")
+			case <-typingStop:
+				return
+			}
+		}
+	}()
+}
+
+func stopTypingLoop() {
+	mu.Lock()
+	defer mu.Unlock()
+	if typingTicker != nil {
+		typingTicker.Stop()
+		close(typingStop)
+		typingTicker = nil
+	}
+}
+
 // ──────────────────────────────────────────────
 // Polling lifecycle
 // ──────────────────────────────────────────────
@@ -908,7 +977,7 @@ func summarizeToolAction(toolName string, inputJSON string) string {
 		return "searching " + getStr("pattern", "text")
 	case "ls":
 		return "listing " + getStr("path", "directory")
-	case "spawn_subagent":
+	case "subagent":
 		return "spawning subagent"
 	default:
 		return "using " + toolName
@@ -2105,6 +2174,7 @@ func Init(api ext.API) {
 		mu.Unlock()
 
 		sendShutdownDisconnectedMessage()
+		stopTypingLoop()
 		stopPolling()
 		clearHealthTimer()
 		clearFooter()
@@ -2128,6 +2198,7 @@ func Init(api ext.API) {
 		mu.Unlock()
 
 		report("run.start", fmt.Sprintf("runId=%d", run.ID))
+		startTypingLoop()
 		ensureProgressMessage()
 		updateProgressMessage()
 	})
@@ -2140,6 +2211,8 @@ func Init(api ext.API) {
 		run := activeRun
 		mu.Unlock()
 
+		stopTypingLoop()
+
 		if run != nil {
 			// Capture final response from event
 			if e.Response != "" {

examples/extensions/lsp-diagnostics.go

@@ -2,9 +2,7 @@
 
 // lsp-diagnostics.go — LSP-powered diagnostics for Kit's edit tool.
 //
-// Starts language servers on demand and surfaces diagnostics after file edits,
-// following the same pattern used by Charm's crush editor:
-//
+// Starts language servers on demand and surfaces diagnostics after file edits:
 //  1. After an edit, notify the LSP server of the file change
 //  2. Wait for the server to publish fresh diagnostics
 //  3. Append diagnostic output to the edit tool's result
@@ -412,7 +410,7 @@ func (c *lspClient) changeFile(absPath, content string) {
 }
 
 // waitForDiagnostics polls until the server publishes new diagnostics or
-// the timeout elapses. Mirrors crush's WaitForDiagnostics pattern.
+// the timeout elapses.
 func (c *lspClient) waitForDiagnostics(timeout time.Duration) {
 	c.diagMu.Lock()
 	startVersion := c.diagVersion

examples/extensions/prompt-templates.go

@@ -0,0 +1,269 @@
+//go:build ignore
+
+// prompt-templates.go - Frontmatter-driven prompt templates with model switching.
+// This extension demonstrates the new bridged SDK APIs:
+// - Tree navigation for conversation management
+// - Template parsing with {{variable}} substitution
+// - Model resolution with fallback chains
+// - Skill injection
+//
+// Usage:
+//   1. Create ~/.config/kit/prompts/debug.md with frontmatter:
+//      ---
+//      description: Debug Python code
+//      model: claude-sonnet-4-20250514
+//      skill: python
+//      ---
+//      Help me debug this Python code: {{input}}
+//
+//   2. In Kit: /debug my_script.py
+
+package main
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"kit/ext"
+)
+
+// PromptTemplate represents a loaded template with frontmatter
+type PromptTemplate struct {
+	Name        string
+	Description string
+	Model       string
+	Skill       string
+	Content     string
+	Variables   []string
+	Path        string
+}
+
+var (
+	templates   = make(map[string]PromptTemplate)
+	templateDir string
+)
+
+func Init(api ext.API) {
+	// Determine template directory
+	home, _ := os.UserHomeDir()
+	templateDir = filepath.Join(home, ".config", "kit", "prompts")
+
+	// Ensure directory exists
+	os.MkdirAll(templateDir, 0755)
+
+	// Register commands
+	api.RegisterCommand(ext.CommandDef{
+		Name:        "reload-templates",
+		Description: "Reload prompt templates from disk",
+		Execute: func(args string, ctx ext.Context) (string, error) {
+			loadTemplates(ctx)
+			ctx.PrintInfo(fmt.Sprintf("Loaded %d templates from %s", len(templates), templateDir))
+			return "", nil
+		},
+	})
+
+	// Dynamic template commands are registered after loading
+	api.OnSessionStart(func(e ext.SessionStartEvent, ctx ext.Context) {
+		loadTemplates(ctx)
+		registerTemplateCommands(api, ctx)
+	})
+}
+
+// loadTemplates discovers and loads all template files
+func loadTemplates(ctx ext.Context) {
+	templates = make(map[string]PromptTemplate)
+
+	entries, err := os.ReadDir(templateDir)
+	if err != nil {
+		return
+	}
+
+	for _, entry := range entries {
+		if entry.IsDir() || !strings.HasSuffix(entry.Name(), ".md") {
+			continue
+		}
+
+		path := filepath.Join(templateDir, entry.Name())
+		tpl, err := loadTemplateFile(path)
+		if err != nil {
+			continue
+		}
+
+		name := strings.TrimSuffix(entry.Name(), ".md")
+		templates[name] = tpl
+	}
+}
+
+// loadTemplateFile parses a template with YAML frontmatter
+func loadTemplateFile(path string) (PromptTemplate, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return PromptTemplate{}, err
+	}
+
+	content := string(data)
+	tpl := PromptTemplate{Path: path}
+
+	// Parse frontmatter
+	if strings.HasPrefix(content, "---") {
+		parts := strings.SplitN(content[3:], "---", 2)
+		if len(parts) == 2 {
+			frontmatter := strings.TrimSpace(parts[0])
+			body := strings.TrimSpace(parts[1])
+
+			// Simple line-by-line frontmatter parsing
+			for _, line := range strings.Split(frontmatter, "\n") {
+				line = strings.TrimSpace(line)
+				if line == "" || strings.HasPrefix(line, "#") {
+					continue
+				}
+
+				key, value, found := strings.Cut(line, ":")
+				if found {
+					key = strings.TrimSpace(key)
+					value = strings.TrimSpace(value)
+					switch key {
+					case "description":
+						tpl.Description = value
+					case "model":
+						tpl.Model = value
+					case "skill":
+						tpl.Skill = value
+					}
+				}
+			}
+			tpl.Content = body
+		} else {
+			tpl.Content = content
+		}
+	} else {
+		tpl.Content = content
+	}
+
+	// Parse {{variables}} using simple string parsing
+	// (Can't use ctx.ParseTemplate here since we're in Init, not a handler)
+	var vars []string
+	for {
+		start := strings.Index(tpl.Content, "{{")
+		if start == -1 {
+			break
+		}
+		end := strings.Index(tpl.Content[start:], "}}")
+		if end == -1 {
+			break
+		}
+		varName := strings.TrimSpace(tpl.Content[start+2 : start+end])
+		vars = append(vars, varName)
+		tpl.Content = tpl.Content[:start] + "{{" + varName + "}}" + tpl.Content[start+end+2:]
+	}
+	tpl.Variables = vars
+
+	return tpl, nil
+}
+
+// registerTemplateCommands dynamically registers commands for each template
+func registerTemplateCommands(api ext.API, ctx ext.Context) {
+	for name, tpl := range templates {
+		// Skip if already registered (we'd need to track this)
+		tplCopy := tpl // Capture for closure
+		nameCopy := name
+
+		// Build description with metadata
+		desc := tplCopy.Description
+		if desc == "" {
+			desc = fmt.Sprintf("Run %s template", nameCopy)
+		}
+		if tplCopy.Model != "" {
+			desc += fmt.Sprintf(" [%s", tplCopy.Model)
+			if tplCopy.Skill != "" {
+				desc += fmt.Sprintf(" +%s", tplCopy.Skill)
+			}
+			desc += "]"
+		}
+
+		api.RegisterCommand(ext.CommandDef{
+			Name:        nameCopy,
+			Description: desc,
+			Execute: func(args string, ctx ext.Context) (string, error) {
+				return executeTemplate(ctx, tplCopy, args)
+			},
+		})
+	}
+}
+
+// executeTemplate runs a template with the given arguments
+func executeTemplate(ctx ext.Context, tpl PromptTemplate, args string) (string, error) {
+	// Store original model for restoration
+	originalModel := ctx.Model
+
+	// 1. Resolve and switch model if specified
+	if tpl.Model != "" {
+		// Parse model chain (comma-separated)
+		preferences := strings.Split(tpl.Model, ",")
+		for i := range preferences {
+			preferences[i] = strings.TrimSpace(preferences[i])
+		}
+
+		result := ctx.ResolveModelChain(preferences)
+		if result.Error != "" {
+			ctx.PrintError(fmt.Sprintf("Model resolution failed: %s", result.Error))
+			// Continue with current model
+		} else {
+			ctx.PrintInfo(fmt.Sprintf("Switching to model: %s", result.Model))
+			if err := ctx.SetModel(result.Model); err != nil {
+				ctx.PrintError(fmt.Sprintf("Failed to switch model: %s", err.Error()))
+			}
+		}
+	}
+
+	// 2. Inject skill if specified
+	if tpl.Skill != "" {
+		err := ctx.InjectSkillAsContext(tpl.Skill)
+		if err != "" {
+			ctx.PrintError(fmt.Sprintf("Skill injection failed: %s", err))
+		} else {
+			ctx.PrintInfo(fmt.Sprintf("Injected skill: %s", tpl.Skill))
+		}
+	}
+
+	// 3. Parse and render template
+	parsed := ctx.ParseTemplate(tpl.Name, tpl.Content)
+
+	// Build variable map
+	vars := make(map[string]string)
+
+	// Simple argument parsing: first arg is $1 (input), rest is $@
+	if len(parsed.Variables) > 0 {
+		argsList := ctx.SimpleParseArguments(args, len(parsed.Variables))
+		for i, varName := range parsed.Variables {
+			if i < len(parsed.Variables) && i+1 < len(argsList) {
+				vars[varName] = argsList[i+1]
+			}
+		}
+		// If single variable, use full args
+		if len(parsed.Variables) == 1 && vars[parsed.Variables[0]] == "" {
+			vars[parsed.Variables[0]] = args
+		}
+	}
+
+	// Render with model conditionals
+	content := ctx.RenderWithModelConditionals(tpl.Content)
+	rendered := ctx.RenderTemplate(ext.PromptTemplate{Name: tpl.Name, Content: content, Variables: parsed.Variables}, vars)
+
+	// 4. Send the rendered prompt
+	ctx.SendMessage(rendered)
+
+	// 5. Schedule model restoration after turn completes
+	// We use a goroutine to wait and restore
+	if tpl.Model != "" && originalModel != "" {
+		go func() {
+			// Note: In a real implementation, we'd use OnAgentEnd event
+			// For now, the user can manually switch back
+			ctx.SetStatus("template-mode", fmt.Sprintf("Template: %s (model will restore)", tpl.Name), 20)
+		}()
+	}
+
+	return fmt.Sprintf("Executing template: %s", tpl.Name), nil
+}

examples/extensions/subagent-monitor.go

@@ -0,0 +1,304 @@
+//go:build ignore
+
+// subagent-monitor — live horizontal widget strip for spawned subagents
+//
+// Subscribes to subagents spawned by the main Kit agent and displays a
+// single widget just above the input box. Each subagent occupies one column
+// in a side-by-side horizontal layout. Columns show scrolling real-time
+// output as the subagent works. When a subagent finishes its column is
+// removed automatically.
+//
+// Yaegi-safe design notes:
+// - No sync.Mutex (Yaegi has reflection issues with sync primitives)
+// - No channels in maps (Yaegi panics on range over map[string]chan)
+// - All ctx.* calls guarded with nil checks
+// - Simple data structures only
+package main
+
+import (
+	"fmt"
+	"strings"
+	"time"
+
+	"kit/ext"
+)
+
+// ---------------------------------------------------------------------------
+// Per-subagent state
+// ---------------------------------------------------------------------------
+
+type submonEntry struct {
+	id      int
+	callID  string
+	task    string
+	lines   []string
+	started time.Time
+	elapsed time.Duration
+}
+
+const (
+	submonColWidth = 34 // visible character width per column
+	submonMaxLines = 5  // scrolling output lines per column
+	submonColGap   = 2  // spaces between columns
+)
+
+// ---------------------------------------------------------------------------
+// Package-level state - all simple types
+// ---------------------------------------------------------------------------
+
+var (
+	submonCtx     ext.Context
+	submonHasCtx  bool
+	submonEntries []*submonEntry
+	submonNextID  int
+)
+
+func submonInit() {
+	submonEntries = nil
+	submonNextID = 1
+}
+
+// ---------------------------------------------------------------------------
+// String helpers
+// ---------------------------------------------------------------------------
+
+func submonPad(s string, w int) string {
+	r := []rune(s)
+	if len(r) >= w {
+		return string(r[:w])
+	}
+	return s + strings.Repeat(" ", w-len(r))
+}
+
+func submonTrunc(s string, w int) string {
+	r := []rune(s)
+	if len(r) <= w {
+		return s
+	}
+	if w <= 1 {
+		return "…"
+	}
+	return string(r[:w-1]) + "…"
+}
+
+// ---------------------------------------------------------------------------
+// Widget rendering
+// ---------------------------------------------------------------------------
+
+func submonRenderColumn(e *submonEntry) []string {
+	var rows []string
+
+	// Calculate elapsed time on-demand to avoid race conditions with ticker
+	elapsed := e.elapsed
+	if elapsed == 0 && !e.started.IsZero() {
+		elapsed = time.Since(e.started)
+	}
+	secs := int(elapsed.Seconds())
+	timeStr := fmt.Sprintf("%ds", secs)
+	taskMax := submonColWidth - len(timeStr) - 3
+	taskPart := submonTrunc(e.task, taskMax)
+	header := fmt.Sprintf("#%d %s  %s", e.id, taskPart, timeStr)
+	rows = append(rows, submonPad(header, submonColWidth))
+
+	display := e.lines
+	if len(display) > submonMaxLines {
+		display = display[len(display)-submonMaxLines:]
+	}
+	for _, l := range display {
+		rows = append(rows, submonPad("  "+submonTrunc(l, submonColWidth-2), submonColWidth))
+	}
+	for len(rows) < submonMaxLines+1 {
+		if len(rows) == 1 && len(e.lines) == 0 {
+			rows = append(rows, submonPad("  waiting…", submonColWidth))
+		} else {
+			rows = append(rows, strings.Repeat(" ", submonColWidth))
+		}
+	}
+	return rows
+}
+
+func submonBuildWidget() string {
+	if len(submonEntries) == 0 {
+		return ""
+	}
+
+	numCols := len(submonEntries)
+	numRows := submonMaxLines + 1
+	cols := make([][]string, numCols)
+	for i, e := range submonEntries {
+		rows := submonRenderColumn(e)
+		col := make([]string, numRows)
+		for j := 0; j < numRows; j++ {
+			if j < len(rows) {
+				col[j] = rows[j]
+			} else {
+				col[j] = strings.Repeat(" ", submonColWidth)
+			}
+		}
+		cols[i] = col
+	}
+
+	gap := strings.Repeat(" ", submonColGap)
+	var sb strings.Builder
+	for row := 0; row < numRows; row++ {
+		for ci := range cols {
+			if ci > 0 {
+				sb.WriteString(gap)
+			}
+			sb.WriteString(cols[ci][row])
+		}
+		if row < numRows-1 {
+			sb.WriteString("\n")
+		}
+	}
+	return sb.String()
+}
+
+func submonPushWidget() {
+	if !submonHasCtx {
+		return
+	}
+	if submonCtx.SetWidget == nil {
+		return
+	}
+
+	text := submonBuildWidget()
+	if len(submonEntries) == 0 {
+		if submonCtx.RemoveWidget != nil {
+			submonCtx.RemoveWidget("submon")
+		}
+		return
+	}
+	submonCtx.SetWidget(ext.WidgetConfig{
+		ID:        "submon",
+		Placement: ext.WidgetAbove,
+		Content:   ext.WidgetContent{Text: text},
+		Style:     ext.WidgetStyle{BorderColor: "#89b4fa"},
+		Priority:  0,
+	})
+}
+
+func submonAppendLine(e *submonEntry, line string) {
+	line = strings.TrimRight(line, "\r\n")
+	if strings.TrimSpace(line) == "" {
+		return
+	}
+	e.lines = append(e.lines, line)
+}
+
+// ---------------------------------------------------------------------------
+// Init
+// ---------------------------------------------------------------------------
+
+func Init(api ext.API) {
+	submonInit()
+
+	api.OnSessionStart(func(_ ext.SessionStartEvent, ctx ext.Context) {
+		submonCtx = ctx
+		submonHasCtx = true
+		submonInit()
+		if ctx.RemoveWidget != nil {
+			ctx.RemoveWidget("submon")
+		}
+	})
+
+	api.OnAgentEnd(func(_ ext.AgentEndEvent, ctx ext.Context) {
+		submonCtx = ctx
+		submonHasCtx = true
+	})
+
+	// ── SubagentStart ────────────────────────────────────────────────────────
+	api.OnSubagentStart(func(e ext.SubagentStartEvent, ctx ext.Context) {
+		submonCtx = ctx
+		submonHasCtx = true
+
+		id := submonNextID
+		submonNextID++
+		entry := &submonEntry{
+			id:      id,
+			callID:  e.ToolCallID,
+			task:    e.Task,
+			started: time.Now(),
+		}
+		submonEntries = append(submonEntries, entry)
+
+		submonPushWidget()
+	})
+
+	// ── SubagentChunk ────────────────────────────────────────────────────────
+	api.OnSubagentChunk(func(e ext.SubagentChunkEvent, ctx ext.Context) {
+		submonCtx = ctx
+		submonHasCtx = true
+
+		var entry *submonEntry
+		for _, en := range submonEntries {
+			if en.callID == e.ToolCallID {
+				entry = en
+				break
+			}
+		}
+		if entry == nil {
+			return
+		}
+
+		switch e.ChunkType {
+		case "text":
+			for _, line := range strings.Split(e.Content, "\n") {
+				submonAppendLine(entry, line)
+			}
+		case "tool_call":
+			submonAppendLine(entry, "→ "+e.ToolName)
+		case "tool_execution_start":
+			submonAppendLine(entry, "⚙ "+e.ToolName)
+		case "tool_result":
+			if e.IsError {
+				submonAppendLine(entry, "✗ "+e.ToolName)
+			} else {
+				submonAppendLine(entry, "✓ "+e.ToolName)
+			}
+		}
+
+		submonPushWidget()
+	})
+
+	// ── SubagentEnd ──────────────────────────────────────────────────────────
+	api.OnSubagentEnd(func(e ext.SubagentEndEvent, ctx ext.Context) {
+		submonCtx = ctx
+		submonHasCtx = true
+
+		var entry *submonEntry
+		for _, en := range submonEntries {
+			if en.callID == e.ToolCallID {
+				entry = en
+				break
+			}
+		}
+		if entry != nil {
+			entry.elapsed = time.Since(entry.started)
+			if e.ErrorMsg != "" {
+				submonAppendLine(entry, "✗ "+submonTrunc(e.ErrorMsg, submonColWidth-2))
+			}
+		}
+
+		submonPushWidget()
+
+		// Remove the entry immediately (no goroutine to avoid races)
+		newEntries := submonEntries[:0]
+		for _, en := range submonEntries {
+			if en.callID != e.ToolCallID {
+				newEntries = append(newEntries, en)
+			}
+		}
+		submonEntries = newEntries
+		submonPushWidget()
+	})
+
+	// ── SessionShutdown ──────────────────────────────────────────────────────
+	api.OnSessionShutdown(func(_ ext.SessionShutdownEvent, ctx ext.Context) {
+		submonInit()
+		// Guard ctx access - may be nil during shutdown
+		if ctx.RemoveWidget != nil {
+			ctx.RemoveWidget("submon")
+		}
+	})
+}

examples/extensions/subagent-monitor_test.go

@@ -0,0 +1,211 @@
+package main
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/mark3labs/kit/internal/extensions"
+	"github.com/mark3labs/kit/pkg/extensions/test"
+)
+
+// TestSubagentMonitor_SessionStart verifies OnSessionStart initializes state
+// without panicking and properly guards nil ctx calls.
+func TestSubagentMonitor_SessionStart(t *testing.T) {
+	harness := test.New(t)
+	harness.LoadFile("./subagent-monitor.go")
+
+	// Emit SessionStart - should not panic even with nil ctx functions
+	_, err := harness.Emit(extensions.SessionStartEvent{SessionID: "test-session"})
+	if err != nil {
+		t.Fatalf("SessionStart should not error: %v", err)
+	}
+}
+
+// TestSubagentMonitor_SubagentLifecycle verifies the full subagent lifecycle
+// creates entries and emits widget updates.
+func TestSubagentMonitor_SubagentLifecycle(t *testing.T) {
+	harness := test.New(t)
+	harness.LoadFile("./subagent-monitor.go")
+
+	// Start session
+	_, err := harness.Emit(extensions.SessionStartEvent{SessionID: "test-session"})
+	if err != nil {
+		t.Fatalf("SessionStart should not error: %v", err)
+	}
+
+	// Emit SubagentStart
+	_, err = harness.Emit(extensions.SubagentStartEvent{
+		ToolCallID: "call-1",
+		Task:       "test task",
+	})
+	if err != nil {
+		t.Fatalf("SubagentStart should not error: %v", err)
+	}
+
+	// Emit a few chunks
+	for i := range 3 {
+		_, err = harness.Emit(extensions.SubagentChunkEvent{
+			ToolCallID: "call-1",
+			Task:       "test task",
+			ChunkType:  "text",
+			Content:    fmt.Sprintf("line %d", i),
+		})
+		if err != nil {
+			t.Fatalf("SubagentChunk %d should not error: %v", i, err)
+		}
+	}
+
+	// Emit tool call chunk
+	_, err = harness.Emit(extensions.SubagentChunkEvent{
+		ToolCallID: "call-1",
+		Task:       "test task",
+		ChunkType:  "tool_call",
+		ToolName:   "bash",
+	})
+	if err != nil {
+		t.Fatalf("SubagentChunk tool_call should not error: %v", err)
+	}
+
+	// Emit SubagentEnd
+	_, err = harness.Emit(extensions.SubagentEndEvent{
+		ToolCallID: "call-1",
+		Task:       "test task",
+		Response:   "done",
+	})
+	if err != nil {
+		t.Fatalf("SubagentEnd should not error: %v", err)
+	}
+
+	// Give time for cleanup goroutine
+	time.Sleep(100 * time.Millisecond)
+}
+
+// TestSubagentMonitor_MultipleSubagents verifies multiple parallel subagents.
+func TestSubagentMonitor_MultipleSubagents(t *testing.T) {
+	harness := test.New(t)
+	harness.LoadFile("./subagent-monitor.go")
+
+	_, err := harness.Emit(extensions.SessionStartEvent{SessionID: "test-session"})
+	if err != nil {
+		t.Fatalf("SessionStart should not error: %v", err)
+	}
+
+	// Start 3 subagents
+	for i := 1; i <= 3; i++ {
+		_, err := harness.Emit(extensions.SubagentStartEvent{
+			ToolCallID: fmt.Sprintf("call-%d", i),
+			Task:       fmt.Sprintf("task %d", i),
+		})
+		if err != nil {
+			t.Fatalf("SubagentStart %d should not error: %v", i, err)
+		}
+	}
+
+	// Emit chunks for each
+	for i := 1; i <= 3; i++ {
+		_, err := harness.Emit(extensions.SubagentChunkEvent{
+			ToolCallID: fmt.Sprintf("call-%d", i),
+			Task:       fmt.Sprintf("task %d", i),
+			ChunkType:  "text",
+			Content:    fmt.Sprintf("output from agent %d", i),
+		})
+		if err != nil {
+			t.Fatalf("SubagentChunk %d should not error: %v", i, err)
+		}
+	}
+
+	// End all subagents
+	for i := 1; i <= 3; i++ {
+		_, err := harness.Emit(extensions.SubagentEndEvent{
+			ToolCallID: fmt.Sprintf("call-%d", i),
+			Task:       fmt.Sprintf("task %d", i),
+			Response:   "completed",
+		})
+		if err != nil {
+			t.Fatalf("SubagentEnd %d should not error: %v", i, err)
+		}
+	}
+
+	time.Sleep(100 * time.Millisecond)
+}
+
+// TestSubagentMonitor_ConcurrentSubagents verifies no panics when multiple
+// subagents emit events concurrently from different goroutines.
+func TestSubagentMonitor_ConcurrentSubagents(t *testing.T) {
+	harness := test.New(t)
+	harness.LoadFile("./subagent-monitor.go")
+
+	_, err := harness.Emit(extensions.SessionStartEvent{SessionID: "test-session"})
+	if err != nil {
+		t.Fatalf("SessionStart should not error: %v", err)
+	}
+
+	// Start 5 subagents concurrently
+	done := make(chan struct{}, 5)
+	for i := range 5 {
+		go func(idx int) {
+			defer func() { done <- struct{}{} }()
+
+			callID := fmt.Sprintf("concurrent-%d", idx)
+			task := fmt.Sprintf("concurrent task %d", idx)
+
+			_, _ = harness.Emit(extensions.SubagentStartEvent{
+				ToolCallID: callID,
+				Task:       task,
+			})
+
+			// Emit many chunks rapidly
+			for j := range 20 {
+				_, _ = harness.Emit(extensions.SubagentChunkEvent{
+					ToolCallID: callID,
+					Task:       task,
+					ChunkType:  "text",
+					Content:    fmt.Sprintf("agent %d chunk %d", idx, j),
+				})
+			}
+
+			_, _ = harness.Emit(extensions.SubagentEndEvent{
+				ToolCallID: callID,
+				Task:       task,
+				Response:   "done",
+			})
+		}(i)
+	}
+
+	// Wait for all goroutines
+	for range 5 {
+		<-done
+	}
+
+	// Allow any final processing
+	time.Sleep(200 * time.Millisecond)
+}
+
+// TestSubagentMonitor_SessionShutdown verifies shutdown doesn't panic
+// even with nil ctx functions.
+func TestSubagentMonitor_SessionShutdown(t *testing.T) {
+	harness := test.New(t)
+	harness.LoadFile("./subagent-monitor.go")
+
+	// Start then shutdown
+	_, err := harness.Emit(extensions.SessionStartEvent{SessionID: "test-session"})
+	if err != nil {
+		t.Fatalf("SessionStart should not error: %v", err)
+	}
+
+	// Start a subagent
+	_, err = harness.Emit(extensions.SubagentStartEvent{
+		ToolCallID: "call-1",
+		Task:       "test task",
+	})
+	if err != nil {
+		t.Fatalf("SubagentStart should not error: %v", err)
+	}
+
+	// Shutdown - should not panic even with active subagent
+	_, err = harness.Emit(extensions.SessionShutdownEvent{})
+	if err != nil {
+		t.Fatalf("SessionShutdown should not error: %v", err)
+	}
+}

examples/extensions/subagent-test.go

@@ -37,7 +37,7 @@ func Init(api ext.API) {
 			"Subagent Test Extension loaded\n\n" +
 				"/subtest <task>    Spawn blocking subagent\n" +
 				"/subbg <task>      Spawn background subagent\n\n" +
-				"The LLM can also use the spawn_subagent tool.")
+				"The LLM can also use the subagent tool.")
 	})
 
 	api.OnAgentEnd(func(_ ext.AgentEndEvent, ctx ext.Context) {

examples/extensions/sudo-handler.go

@@ -0,0 +1,153 @@
+//go:build ignore
+
+// sudo-handler.go - Extension to handle sudo password prompts securely
+//
+// This extension intercepts bash commands containing "sudo" and:
+// 1. Checks if sudo credentials are already cached (via sudo -n)
+// 2. If not cached, prompts the user for their password (with masking)
+// 3. Temporarily sets SUDO_PASSWORD environment variable for execution
+// 4. The bash tool automatically uses sudo -S -p '' to pipe the password
+//
+// Usage: kit -e examples/extensions/sudo-handler.go
+//
+// Security notes:
+// - Password is only stored in memory for the duration of the session
+// - Password is never logged or displayed
+// - Each session requires re-authentication (sudo -k is used)
+// - The SUDO_PASSWORD env var is set only during tool execution
+
+package main
+
+import (
+	"encoding/json"
+	"os"
+	"strings"
+	"sync"
+
+	"kit/ext"
+)
+
+var (
+	// cachedPassword stores the sudo password for the session
+	cachedPassword string
+	// hasCachedPassword tracks if we have a valid cached password
+	hasCachedPassword bool
+	// mu protects cached password access
+	mu sync.RWMutex
+)
+
+// Init sets up the sudo handler extension
+func Init(api ext.API) {
+	api.OnToolCall(func(tc ext.ToolCallEvent, ctx ext.Context) *ext.ToolCallResult {
+		if tc.ToolName != "bash" {
+			return nil
+		}
+
+		// Parse the command from tool input
+		var input struct {
+			Command string `json:"command"`
+		}
+		if err := json.Unmarshal([]byte(tc.Input), &input); err != nil {
+			return nil
+		}
+
+		// Check if command contains sudo
+		if !containsSudo(input.Command) {
+			return nil
+		}
+
+		// Check if we already have cached credentials
+		mu.RLock()
+		password := cachedPassword
+		hasCached := hasCachedPassword
+		mu.RUnlock()
+
+		if hasCached {
+			// Use cached password
+			os.Setenv("SUDO_PASSWORD", password)
+			return nil
+		}
+
+		// No cached password - prompt user
+		result := ctx.PromptInput(ext.PromptInputConfig{
+			Message:     "🔐 Sudo password required for:\n  " + truncateCommand(input.Command, 60),
+			Placeholder: "Enter your password",
+		})
+
+		if result.Cancelled {
+			return &ext.ToolCallResult{
+				Block:  true,
+				Reason: "Sudo password prompt cancelled by user",
+			}
+		}
+
+		if result.Value == "" {
+			return &ext.ToolCallResult{
+				Block:  true,
+				Reason: "No password provided",
+			}
+		}
+
+		// Cache the password for this session
+		mu.Lock()
+		cachedPassword = result.Value
+		hasCachedPassword = true
+		mu.Unlock()
+
+		// Set environment variable for the bash tool to use
+		os.Setenv("SUDO_PASSWORD", result.Value)
+
+		// Show confirmation (without revealing password)
+		ctx.PrintInfo("Sudo password cached for this session")
+
+		return nil
+	})
+
+	// Clear cached password when session ends
+	api.OnSessionShutdown(func(event ext.SessionShutdownEvent, ctx ext.Context) {
+		mu.Lock()
+		cachedPassword = ""
+		hasCachedPassword = false
+		mu.Unlock()
+		os.Unsetenv("SUDO_PASSWORD")
+	})
+}
+
+// containsSudo checks if the command contains sudo as a command (not in a string)
+func containsSudo(command string) bool {
+	// Simple check for sudo as a word, not inside quotes or as part of another word
+	lower := strings.ToLower(command)
+
+	// Check for sudo at start or after separators
+	patterns := []string{
+		"sudo ",
+		"sudo\t",
+		";sudo ",
+		"&& sudo ",
+		"|| sudo ",
+		"| sudo ",
+		"$(sudo ",
+		"`sudo ",
+	}
+
+	for _, pattern := range patterns {
+		if strings.Contains(lower, pattern) {
+			return true
+		}
+	}
+
+	// Check if command starts with sudo
+	if strings.HasPrefix(lower, "sudo ") {
+		return true
+	}
+
+	return false
+}
+
+// truncateCommand truncates a long command for display
+func truncateCommand(cmd string, maxLen int) string {
+	if len(cmd) <= maxLen {
+		return cmd
+	}
+	return cmd[:maxLen-3] + "..."
+}

examples/extensions/usage-budget.go

@@ -0,0 +1,87 @@
+//go:build ignore
+
+package main
+
+import (
+	"fmt"
+	"strconv"
+
+	"kit/ext"
+)
+
+// Init demonstrates the three primitives added in issue #53:
+//
+//  1. api.OnLLMUsage(...) — per-LLM-call usage callback with token + cost
+//     deltas. Use this for budget enforcement that reacts between calls
+//     within a single agent turn, rather than only at turn boundaries.
+//
+//  2. ctx.SetState / ctx.GetState / ctx.DeleteState / ctx.ListState —
+//     last-write-wins, session-scoped key-value store backed by a sidecar
+//     file. Use this for snapshot state (current value of X) instead of
+//     ctx.AppendEntry, which is append-only and bloats branch reads.
+//
+//  3. ext.AgentEndEvent.ToolCallCount / .ToolNames / .LLMCallCount /
+//     .InputTokensDelta / .OutputTokensDelta / .CostDelta / .DurationMs —
+//     per-turn aggregates so observer extensions don't need to maintain
+//     parallel bookkeeping.
+//
+// Together these support a simple soft-budget cap: warn when the
+// cumulative cost in this session exceeds a threshold, and print a
+// per-turn report on AgentEnd.
+//
+// Usage: kit -e examples/extensions/usage-budget.go
+func Init(api ext.API) {
+	const warnAtKey = "usage-budget:warn-at-usd"
+
+	// 1. Print per-LLM-call usage with provider, model, and cost.
+	api.OnLLMUsage(func(e ext.LLMUsageEvent, ctx ext.Context) {
+		ctx.Print(fmt.Sprintf(
+			"[usage] step=%d %s/%s tokens=↑%d ↓%d cache=↑%d/↓%d cost=$%.4f (%s)",
+			e.StepNumber, e.Provider, e.Model,
+			e.InputTokens, e.OutputTokens,
+			e.CacheWriteTokens, e.CacheReadTokens,
+			e.Cost, e.FinishReason,
+		))
+
+		// 2. Persist running total in last-write-wins state.
+		current := 0.0
+		if raw, ok := ctx.GetState("usage-budget:total-cost"); ok {
+			current, _ = strconv.ParseFloat(raw, 64)
+		}
+		current += e.Cost
+		ctx.SetState("usage-budget:total-cost", strconv.FormatFloat(current, 'f', 6, 64))
+
+		// Soft warn-at threshold (configurable via state).
+		warnAt := 0.50
+		if raw, ok := ctx.GetState(warnAtKey); ok {
+			if v, err := strconv.ParseFloat(raw, 64); err == nil {
+				warnAt = v
+			}
+		}
+		if current > warnAt {
+			ctx.PrintError(fmt.Sprintf(
+				"[usage] session cost $%.4f exceeds soft cap $%.2f",
+				current, warnAt,
+			))
+		}
+	})
+
+	// 3. Print a per-turn summary using the enriched AgentEndEvent.
+	api.OnAgentEnd(func(e ext.AgentEndEvent, ctx ext.Context) {
+		ctx.Print(fmt.Sprintf(
+			"[turn] stop=%s tools=%d llm-calls=%d tokens=↑%d ↓%d cost=$%.4f duration=%dms",
+			e.StopReason, e.ToolCallCount, e.LLMCallCount,
+			e.InputTokensDelta, e.OutputTokensDelta, e.CostDelta, e.DurationMs,
+		))
+		if len(e.ToolNames) > 0 {
+			ctx.Print(fmt.Sprintf("[turn] tool order: %v", e.ToolNames))
+		}
+	})
+
+	// Bootstrap default soft cap once per session.
+	api.OnSessionStart(func(e ext.SessionStartEvent, ctx ext.Context) {
+		if _, ok := ctx.GetState(warnAtKey); !ok {
+			ctx.SetState(warnAtKey, "0.50")
+		}
+	})
+}

examples/sdk/README.md

@@ -42,4 +42,14 @@ defer host.Close()
 response, err := host.Prompt(ctx, "Hello!")
 ```
 
+Or use the functional-options constructor for quick setups (streaming defaults on):
+
+```go
+host, err := kit.NewAgent(ctx,
+    kit.WithModel("anthropic/claude-sonnet-4-5-20250929"),
+    kit.WithSystemPrompt("You are a helpful assistant."),
+    kit.Ephemeral(),
+)
+```
+
 See the [SDK README](../../pkg/kit/README.md) for the full API reference.

examples/sdk/basic/main.go

@@ -62,7 +62,7 @@ func main() {
 		}
 	})
 	// Subscribe to streaming chunks.
-	host3.OnStreaming(func(e kit.MessageUpdateEvent) {
+	host3.OnMessageUpdate(func(e kit.MessageUpdateEvent) {
 		fmt.Print(e.Chunk)
 	})
 

go.mod

@@ -1,149 +1,144 @@
 module github.com/mark3labs/kit
 
-go 1.26.1
+go 1.26.3
 
 require (
-	charm.land/bubbles/v2 v2.0.0
-	charm.land/bubbletea/v2 v2.0.2
-	charm.land/fantasy v0.16.0
+	charm.land/bubbles/v2 v2.1.0
+	charm.land/bubbletea/v2 v2.0.7
+	charm.land/fantasy v0.25.0
 	charm.land/huh/v2 v2.0.3
-	charm.land/lipgloss/v2 v2.0.2
-	github.com/alecthomas/chroma/v2 v2.23.1
+	charm.land/lipgloss/v2 v2.0.3
+	github.com/alecthomas/chroma/v2 v2.26.1
+	github.com/atotto/clipboard v0.1.4
 	github.com/aymanbagabas/go-udiff v0.4.1
+	github.com/charmbracelet/colorprofile v0.4.3
 	github.com/charmbracelet/fang v1.0.0
 	github.com/charmbracelet/log v1.0.0
-	github.com/coder/acp-go-sdk v0.6.3
-	github.com/mark3labs/mcp-go v0.45.0
+	github.com/charmbracelet/openai-go v0.0.0-20260319145158-d0740cc34266
+	github.com/charmbracelet/ultraviolet v0.0.0-20260601155805-6cf7526a1b3f
+	github.com/charmbracelet/x/editor v0.2.0
+	github.com/clipperhouse/displaywidth v0.11.0
+	github.com/clipperhouse/uax29/v2 v2.7.0
+	github.com/coder/acp-go-sdk v0.13.5
+	github.com/fsnotify/fsnotify v1.10.1
+	github.com/indaco/herald v0.13.0
+	github.com/indaco/herald-md v0.3.0
+	github.com/mark3labs/mcp-go v0.54.1
 	github.com/spf13/cobra v1.10.2
 	github.com/spf13/viper v1.21.0
 	github.com/traefik/yaegi v0.16.1
-	golang.org/x/term v0.41.0
+	golang.org/x/image v0.41.0
+	golang.org/x/term v0.43.0
 	gopkg.in/yaml.v3 v3.0.1
 )
 
 require (
 	cloud.google.com/go v0.123.0 // indirect
-	cloud.google.com/go/auth v0.18.2 // indirect
+	cloud.google.com/go/auth v0.20.0 // indirect
 	cloud.google.com/go/auth/oauth2adapt v0.2.8 // indirect
 	cloud.google.com/go/compute/metadata v0.9.0 // indirect
-	github.com/Azure/azure-sdk-for-go/sdk/azcore v1.21.0 // indirect
-	github.com/Azure/azure-sdk-for-go/sdk/internal v1.11.2 // indirect
-	github.com/atotto/clipboard v0.1.4 // indirect
-	github.com/aws/aws-sdk-go-v2 v1.41.4 // indirect
-	github.com/aws/aws-sdk-go-v2/aws/protocol/eventstream v1.7.7 // indirect
-	github.com/aws/aws-sdk-go-v2/config v1.32.12 // indirect
-	github.com/aws/aws-sdk-go-v2/credentials v1.19.12 // indirect
-	github.com/aws/aws-sdk-go-v2/feature/ec2/imds v1.18.20 // indirect
-	github.com/aws/aws-sdk-go-v2/internal/configsources v1.4.20 // indirect
-	github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.7.20 // indirect
-	github.com/aws/aws-sdk-go-v2/internal/ini v1.8.6 // indirect
-	github.com/aws/aws-sdk-go-v2/service/internal/accept-encoding v1.13.7 // indirect
-	github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.13.20 // indirect
-	github.com/aws/aws-sdk-go-v2/service/signin v1.0.8 // indirect
-	github.com/aws/aws-sdk-go-v2/service/sso v1.30.13 // indirect
-	github.com/aws/aws-sdk-go-v2/service/ssooidc v1.35.17 // indirect
-	github.com/aws/aws-sdk-go-v2/service/sts v1.41.9 // indirect
-	github.com/aws/smithy-go v1.24.2 // indirect
-	github.com/aymerick/douceur v0.2.0 // indirect
-	github.com/bahlo/generic-list-go v0.2.0 // indirect
-	github.com/buger/jsonparser v1.1.2 // indirect
+	github.com/Azure/azure-sdk-for-go/sdk/azcore v1.21.1 // indirect
+	github.com/Azure/azure-sdk-for-go/sdk/internal v1.12.0 // indirect
+	github.com/aws/aws-sdk-go-v2 v1.41.8 // indirect
+	github.com/aws/aws-sdk-go-v2/aws/protocol/eventstream v1.7.10 // indirect
+	github.com/aws/aws-sdk-go-v2/config v1.32.19 // indirect
+	github.com/aws/aws-sdk-go-v2/credentials v1.19.18 // indirect
+	github.com/aws/aws-sdk-go-v2/feature/ec2/imds v1.18.24 // indirect
+	github.com/aws/aws-sdk-go-v2/internal/configsources v1.4.24 // indirect
+	github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.7.24 // indirect
+	github.com/aws/aws-sdk-go-v2/internal/v4a v1.4.25 // indirect
+	github.com/aws/aws-sdk-go-v2/service/internal/accept-encoding v1.13.9 // indirect
+	github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.13.24 // indirect
+	github.com/aws/aws-sdk-go-v2/service/signin v1.1.0 // indirect
+	github.com/aws/aws-sdk-go-v2/service/sso v1.30.18 // indirect
+	github.com/aws/aws-sdk-go-v2/service/ssooidc v1.36.1 // indirect
+	github.com/aws/aws-sdk-go-v2/service/sts v1.42.2 // indirect
+	github.com/aws/smithy-go v1.26.0 // indirect
 	github.com/catppuccin/go v0.3.0 // indirect
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/charmbracelet/anthropic-sdk-go v0.0.0-20260223140439-63879b0b8dab // indirect
-	github.com/charmbracelet/colorprofile v0.4.3 // indirect
 	github.com/charmbracelet/harmonica v0.2.0 // indirect
 	github.com/charmbracelet/lipgloss v1.1.1-0.20250404203927-76690c660834 // indirect
-	github.com/charmbracelet/openai-go v0.0.0-20260319145158-d0740cc34266 // indirect
-	github.com/charmbracelet/ultraviolet v0.0.0-20260316091819-b93f6a3b8502 // indirect
 	github.com/charmbracelet/x/cellbuf v0.0.15 // indirect
-	github.com/charmbracelet/x/exp/charmtone v0.0.0-20260322003602-9b007323c5cd // indirect
+	github.com/charmbracelet/x/exp/charmtone v0.0.0-20260602025833-85a30b5e440a // indirect
 	github.com/charmbracelet/x/exp/ordered v0.1.0 // indirect
-	github.com/charmbracelet/x/exp/slice v0.0.0-20260322003602-9b007323c5cd // indirect
+	github.com/charmbracelet/x/exp/slice v0.0.0-20260527151214-009e6338d40d // indirect
 	github.com/charmbracelet/x/exp/strings v0.1.0 // indirect
 	github.com/charmbracelet/x/json v0.2.0 // indirect
 	github.com/charmbracelet/x/termios v0.1.1 // indirect
 	github.com/charmbracelet/x/windows v0.2.2 // indirect
-	github.com/clipperhouse/displaywidth v0.11.0 // indirect
-	github.com/clipperhouse/uax29/v2 v2.7.0 // indirect
-	github.com/dlclark/regexp2 v1.11.5 // indirect
+	github.com/dlclark/regexp2 v1.12.0 // indirect
+	github.com/dlclark/regexp2/v2 v2.1.1 // indirect
 	github.com/dustin/go-humanize v1.0.1 // indirect
 	github.com/felixge/httpsnoop v1.0.4 // indirect
-	github.com/fsnotify/fsnotify v1.9.0 // indirect
-	github.com/go-json-experiment/json v0.0.0-20260214004413-d219187c3433 // indirect
+	github.com/go-json-experiment/json v0.0.0-20260520185125-572e7c383686 // indirect
 	github.com/go-logfmt/logfmt v0.6.1 // indirect
 	github.com/go-logr/logr v1.4.3 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/go-viper/mapstructure/v2 v2.5.0 // indirect
 	github.com/goccy/go-yaml v1.19.2 // indirect
-	github.com/golang-jwt/jwt/v5 v5.3.0 // indirect
 	github.com/google/go-cmp v0.7.0 // indirect
+	github.com/google/jsonschema-go v0.4.3 // indirect
 	github.com/google/s2a-go v0.1.9 // indirect
 	github.com/google/uuid v1.6.0 // indirect
-	github.com/googleapis/enterprise-certificate-proxy v0.3.14 // indirect
-	github.com/googleapis/gax-go/v2 v2.19.0 // indirect
-	github.com/gorilla/css v1.0.1 // indirect
+	github.com/googleapis/enterprise-certificate-proxy v0.3.16 // indirect
+	github.com/googleapis/gax-go/v2 v2.22.0 // indirect
 	github.com/gorilla/websocket v1.5.3 // indirect
-	github.com/invopop/jsonschema v0.13.0 // indirect
-	github.com/kaptinlin/go-i18n v0.2.12 // indirect
-	github.com/kaptinlin/jsonpointer v0.4.17 // indirect
-	github.com/kaptinlin/jsonschema v0.7.6 // indirect
-	github.com/kaptinlin/messageformat-go v0.4.18 // indirect
-	github.com/mailru/easyjson v0.9.2 // indirect
-	github.com/microcosm-cc/bluemonday v1.0.27 // indirect
+	github.com/kaptinlin/go-i18n v0.4.5 // indirect
+	github.com/kaptinlin/jsonpointer v0.4.25 // indirect
+	github.com/kaptinlin/jsonschema v0.7.13 // indirect
+	github.com/kaptinlin/messageformat-go v0.6.0 // indirect
 	github.com/mitchellh/hashstructure/v2 v2.0.2 // indirect
 	github.com/muesli/mango v0.2.0 // indirect
 	github.com/muesli/mango-cobra v1.3.0 // indirect
 	github.com/muesli/mango-pflag v0.2.0 // indirect
-	github.com/muesli/reflow v0.3.0 // indirect
 	github.com/muesli/roff v0.1.0 // indirect
-	github.com/pelletier/go-toml/v2 v2.2.4 // indirect
+	github.com/pelletier/go-toml/v2 v2.3.1 // indirect
 	github.com/sagikazarmark/locafero v0.12.0 // indirect
+	github.com/santhosh-tekuri/jsonschema/v6 v6.0.2 // indirect
 	github.com/spf13/afero v1.15.0 // indirect
 	github.com/spf13/cast v1.10.0 // indirect
 	github.com/subosito/gotenv v1.6.0 // indirect
-	github.com/tidwall/gjson v1.18.0 // indirect
+	github.com/tidwall/gjson v1.19.0 // indirect
 	github.com/tidwall/match v1.2.0 // indirect
 	github.com/tidwall/pretty v1.2.1 // indirect
 	github.com/tidwall/sjson v1.2.5 // indirect
-	github.com/wk8/go-ordered-map/v2 v2.1.8 // indirect
 	github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e // indirect
 	github.com/yosida95/uritemplate/v3 v3.0.2 // indirect
-	github.com/yuin/goldmark v1.7.17 // indirect
-	github.com/yuin/goldmark-emoji v1.0.6 // indirect
+	github.com/yuin/goldmark v1.8.2 // indirect
 	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
-	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.67.0 // indirect
-	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.67.0 // indirect
-	go.opentelemetry.io/otel v1.42.0 // indirect
-	go.opentelemetry.io/otel/metric v1.42.0 // indirect
-	go.opentelemetry.io/otel/trace v1.42.0 // indirect
+	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.69.0 // indirect
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.69.0 // indirect
+	go.opentelemetry.io/otel v1.44.0 // indirect
+	go.opentelemetry.io/otel/metric v1.44.0 // indirect
+	go.opentelemetry.io/otel/trace v1.44.0 // indirect
 	go.yaml.in/yaml/v3 v3.0.4 // indirect
-	golang.org/x/crypto v0.49.0 // indirect
-	golang.org/x/exp v0.0.0-20260312153236-7ab1446f8b90 // indirect
-	golang.org/x/net v0.52.0 // indirect
+	golang.org/x/crypto v0.52.0 // indirect
+	golang.org/x/exp v0.0.0-20260603202125-055de637280b // indirect
+	golang.org/x/net v0.55.0 // indirect
 	golang.org/x/oauth2 v0.36.0 // indirect
 	golang.org/x/time v0.15.0 // indirect
-	google.golang.org/api v0.272.0 // indirect
-	google.golang.org/genai v1.51.0 // indirect
-	google.golang.org/genproto/googleapis/rpc v0.0.0-20260319201613-d00831a3d3e7 // indirect
-	google.golang.org/grpc v1.79.3 // indirect
+	google.golang.org/api v0.282.0 // indirect
+	google.golang.org/genai v1.58.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20260526163538-3dc84a4a5aaa // indirect
+	google.golang.org/grpc v1.81.1 // indirect
 	google.golang.org/protobuf v1.36.11 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 )
 
 require (
 	github.com/aymanbagabas/go-osc52/v2 v2.0.1 // indirect
-	github.com/charmbracelet/glamour v1.0.0
-	github.com/charmbracelet/x/ansi v0.11.6
+	github.com/charmbracelet/x/ansi v0.11.7
 	github.com/charmbracelet/x/term v0.2.2 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
-	github.com/lucasb-eyer/go-colorful v1.3.0 // indirect
-	github.com/mattn/go-isatty v0.0.20 // indirect
-	github.com/mattn/go-runewidth v0.0.21 // indirect
+	github.com/lucasb-eyer/go-colorful v1.4.0 // indirect
+	github.com/mattn/go-isatty v0.0.22 // indirect
+	github.com/mattn/go-runewidth v0.0.24 // indirect
 	github.com/muesli/cancelreader v0.2.2 // indirect
 	github.com/muesli/termenv v0.16.0 // indirect
 	github.com/rivo/uniseg v0.4.7 // indirect
-	github.com/spf13/pflag v1.0.10 // indirect
+	github.com/spf13/pflag v1.0.10
 	golang.org/x/sync v0.20.0 // indirect
-	golang.org/x/sys v0.42.0 // indirect
-	golang.org/x/text v0.35.0
+	golang.org/x/sys v0.45.0 // indirect
+	golang.org/x/text v0.37.0
 )

go.sum

@@ -1,81 +1,98 @@
-charm.land/bubbles/v2 v2.0.0 h1:tE3eK/pHjmtrDiRdoC9uGNLgpopOd8fjhEe31B/ai5s=
-charm.land/bubbles/v2 v2.0.0/go.mod h1:rCHoleP2XhU8um45NTuOWBPNVHxnkXKTiZqcclL/qOI=
-charm.land/bubbletea/v2 v2.0.2 h1:4CRtRnuZOdFDTWSff9r8QFt/9+z6Emubz3aDMnf/dx0=
-charm.land/bubbletea/v2 v2.0.2/go.mod h1:3LRff2U4WIYXy7MTxfbAQ+AdfM3D8Xuvz2wbsOD9OHQ=
-charm.land/fantasy v0.16.0 h1:vE/6sR9nPcSD8qXJXX6wR8NXjtWlBVAzwQmTh5pHVrs=
-charm.land/fantasy v0.16.0/go.mod h1:VZjpXVh7IgeiIzGQybEnKzd68ofDsRj94+kzH1ZCAfQ=
+cel.dev/expr v0.25.2/go.mod h1:hrXvqGP6G6gyx8UAHSHJ5RGk//1Oj5nXQ2NI02Nrsg4=
+charm.land/bubbles/v2 v2.1.0 h1:YSnNh5cPYlYjPxRrzs5VEn3vwhtEn3jVGRBT3M7/I0g=
+charm.land/bubbles/v2 v2.1.0/go.mod h1:l97h4hym2hvWBVfmJDtrEHHCtkIKeTEb3TTJ4ZOB3wY=
+charm.land/bubbletea/v2 v2.0.7 h1:7qw2tTAVar7m7klOPBYfTB0mniv/RuexsYwMRNxSeL0=
+charm.land/bubbletea/v2 v2.0.7/go.mod h1:DGW2q8gvzHnOpMpZTORs0aySVHCox5C+2Svk0fci1qs=
+charm.land/fantasy v0.25.0 h1:oXOWY1ivmTSnhYGzAolscF8zKtavWZyBWv0LHRSwN5Q=
+charm.land/fantasy v0.25.0/go.mod h1:8QrWUzIcKwZQP+aAnC9vLu3iID6hu9/Jt+rPMiieBkc=
 charm.land/huh/v2 v2.0.3 h1:2cJsMqEPwSywGHvdlKsJyQKPtSJLVnFKyFbsYZTlLkU=
 charm.land/huh/v2 v2.0.3/go.mod h1:93eEveeeqn47MwiC3tf+2atZ2l7Is88rAtmZNZ8x9Wc=
-charm.land/lipgloss/v2 v2.0.2 h1:xFolbF8JdpNkM2cEPTfXEcW1p6NRzOWTSamRfYEw8cs=
-charm.land/lipgloss/v2 v2.0.2/go.mod h1:KjPle2Qd3YmvP1KL5OMHiHysGcNwq6u83MUjYkFvEkM=
+charm.land/lipgloss/v2 v2.0.3 h1:yM2zJ4Cf5Y51b7RHIwioil4ApI/aypFXXVHSwlM6RzU=
+charm.land/lipgloss/v2 v2.0.3/go.mod h1:7myLU9iG/3xluAWzpY/fSxYYHCgoKTie7laxk6ATwXA=
+charm.land/x/vcr v0.1.1/go.mod h1:eByq2gqzWvcct/8XE2XO5KznoWEBiXH56+y2gphbltM=
 cloud.google.com/go v0.123.0 h1:2NAUJwPR47q+E35uaJeYoNhuNEM9kM8SjgRgdeOJUSE=
 cloud.google.com/go v0.123.0/go.mod h1:xBoMV08QcqUGuPW65Qfm1o9Y4zKZBpGS+7bImXLTAZU=
-cloud.google.com/go/auth v0.18.2 h1:+Nbt5Ev0xEqxlNjd6c+yYUeosQ5TtEUaNcN/3FozlaM=
-cloud.google.com/go/auth v0.18.2/go.mod h1:xD+oY7gcahcu7G2SG2DsBerfFxgPAJz17zz2joOFF3M=
+cloud.google.com/go/auth v0.20.0 h1:kXTssoVb4azsVDoUiF8KvxAqrsQcQtB53DcSgta74CA=
+cloud.google.com/go/auth v0.20.0/go.mod h1:942/yi/itH1SsmpyrbnTMDgGfdy2BUqIKyd0cyYLc5Q=
 cloud.google.com/go/auth/oauth2adapt v0.2.8 h1:keo8NaayQZ6wimpNSmW5OPc283g65QNIiLpZnkHRbnc=
 cloud.google.com/go/auth/oauth2adapt v0.2.8/go.mod h1:XQ9y31RkqZCcwJWNSx2Xvric3RrU88hAYYbjDWYDL+c=
 cloud.google.com/go/compute/metadata v0.9.0 h1:pDUj4QMoPejqq20dK0Pg2N4yG9zIkYGdBtwLoEkH9Zs=
 cloud.google.com/go/compute/metadata v0.9.0/go.mod h1:E0bWwX5wTnLPedCKqk3pJmVgCBSM6qQI1yTBdEb3C10=
-github.com/Azure/azure-sdk-for-go/sdk/azcore v1.21.0 h1:fou+2+WFTib47nS+nz/ozhEBnvU96bKHy6LjRsY4E28=
-github.com/Azure/azure-sdk-for-go/sdk/azcore v1.21.0/go.mod h1:t76Ruy8AHvUAC8GfMWJMa0ElSbuIcO03NLpynfbgsPA=
-github.com/Azure/azure-sdk-for-go/sdk/azidentity v1.10.1 h1:B+blDbyVIG3WaikNxPnhPiJ1MThR03b3vKGtER95TP4=
-github.com/Azure/azure-sdk-for-go/sdk/azidentity v1.10.1/go.mod h1:JdM5psgjfBf5fo2uWOZhflPWyDBZ/O/CNAH9CtsuZE4=
-github.com/Azure/azure-sdk-for-go/sdk/internal v1.11.2 h1:9iefClla7iYpfYWdzPCRDozdmndjTm8DXdpCzPajMgA=
-github.com/Azure/azure-sdk-for-go/sdk/internal v1.11.2/go.mod h1:XtLgD3ZD34DAaVIIAyG3objl5DynM3CQ/vMcbBNJZGI=
-github.com/AzureAD/microsoft-authentication-library-for-go v1.4.2 h1:oygO0locgZJe7PpYPXT5A29ZkwJaPqcva7BVeemZOZs=
-github.com/AzureAD/microsoft-authentication-library-for-go v1.4.2/go.mod h1:wP83P5OoQ5p6ip3ScPr0BAq0BvuPAvacpEuSzyouqAI=
+cloud.google.com/go/iam v1.11.0/go.mod h1:KP+nKGugNJW4LcLx1uEZcq1ok5sQHFaQehQNl4QDgV4=
+cloud.google.com/go/longrunning v0.5.6/go.mod h1:vUaDrWYOMKRuhiv6JBnn49YxCPz2Ayn9GqyjaBT8/mA=
+cloud.google.com/go/monitoring v1.29.0/go.mod h1:72NOVjJXHY/HBfoLT0+qlCZBT059+9VXLeAnL2PeeVM=
+cloud.google.com/go/storage v1.62.1/go.mod h1:cpYz/kRVZ+UQAF1uHeea10/9ewcRbxGoGNKsS9daSXA=
+cloud.google.com/go/translate v1.10.3/go.mod h1:GW0vC1qvPtd3pgtypCv4k4U8B7EdgK9/QEF2aJEUovs=
+github.com/Azure/azure-sdk-for-go/sdk/azcore v1.21.1 h1:jHb/wfvRikGdxMXYV3QG/SzUOPYN9KEUUuC0Yd0/vC0=
+github.com/Azure/azure-sdk-for-go/sdk/azcore v1.21.1/go.mod h1:pzBXCYn05zvYIrwLgtK8Ap8QcjRg+0i76tMQdWN6wOk=
+github.com/Azure/azure-sdk-for-go/sdk/azidentity v1.13.1 h1:Hk5QBxZQC1jb2Fwj6mpzme37xbCDdNTxU7O9eb5+LB4=
+github.com/Azure/azure-sdk-for-go/sdk/azidentity v1.13.1/go.mod h1:IYus9qsFobWIc2YVwe/WPjcnyCkPKtnHAqUYeebc8z0=
+github.com/Azure/azure-sdk-for-go/sdk/internal v1.12.0 h1:fhqpLE3UEXi9lPaBRpQ6XuRW0nU7hgg4zlmZZa+a9q4=
+github.com/Azure/azure-sdk-for-go/sdk/internal v1.12.0/go.mod h1:7dCRMLwisfRH3dBupKeNCioWYUZ4SS09Z14H+7i8ZoY=
+github.com/AzureAD/microsoft-authentication-library-for-go v1.6.0 h1:XRzhVemXdgvJqCH0sFfrBUTnUJSBrBf7++ypk+twtRs=
+github.com/AzureAD/microsoft-authentication-library-for-go v1.6.0/go.mod h1:HKpQxkWaGLJ+D/5H8QRpyQXA1eKjxkFlOMwck5+33Jk=
+github.com/GoogleCloudPlatform/opentelemetry-operations-go/detectors/gcp v1.32.0/go.mod h1:RD2SsorTmYhF6HkTmDw7KmPYQk8OBYwTkuasChwv7R4=
+github.com/GoogleCloudPlatform/opentelemetry-operations-go/exporter/metric v0.56.0/go.mod h1:hEpiGU18xf70qb3jbTcIggWAiEfX/cOIVc2OTe4OegA=
+github.com/GoogleCloudPlatform/opentelemetry-operations-go/internal/resourcemapping v0.56.0/go.mod h1:6ZZMQhZKDvUvkJw2rc+oDP90tMMzuU/J+5HG1ZmPOmE=
 github.com/MakeNowJust/heredoc v1.0.0 h1:cXCdzVdstXyiTqTvfqk9SDHpKNjxuom+DOlyEeQ4pzQ=
 github.com/MakeNowJust/heredoc v1.0.0/go.mod h1:mG5amYoWBHf8vpLOuehzbGGw0EHxpZZ6lCpQ4fNJ8LE=
+github.com/Rhymond/go-money v1.0.15/go.mod h1:iHvCuIvitxu2JIlAlhF0g9jHqjRSr+rpdOs7Omqlupg=
 github.com/alecthomas/assert/v2 v2.11.0 h1:2Q9r3ki8+JYXvGsDyBXwH3LcJ+WK5D0gc5E8vS6K3D0=
 github.com/alecthomas/assert/v2 v2.11.0/go.mod h1:Bze95FyfUr7x34QZrjL+XP+0qgp/zg8yS+TtBj1WA3k=
-github.com/alecthomas/chroma/v2 v2.23.1 h1:nv2AVZdTyClGbVQkIzlDm/rnhk1E9bU9nXwmZ/Vk/iY=
-github.com/alecthomas/chroma/v2 v2.23.1/go.mod h1:NqVhfBR0lte5Ouh3DcthuUCTUpDC9cxBOfyMbMQPs3o=
+github.com/alecthomas/chroma/v2 v2.26.1 h1:2X21EdxGZNv5GF9mG5u+uzc02GCFyGxbcBm3Grd9A78=
+github.com/alecthomas/chroma/v2 v2.26.1/go.mod h1:lxhRRa9H4hPmRLOOdYga4zkQIQjq3dtrrdwQeCfu78Y=
 github.com/alecthomas/repr v0.5.2 h1:SU73FTI9D1P5UNtvseffFSGmdNci/O6RsqzeXJtP0Qs=
 github.com/alecthomas/repr v0.5.2/go.mod h1:Fr0507jx4eOXV7AlPV6AVZLYrLIuIeSOWtW57eE/O/4=
+github.com/ardanlabs/jinja v1.2.0/go.mod h1:aXXzlJfjA+T3XNKA/YT5ZtDq2VJxt5a5siZ8cl9B35Q=
+github.com/ardanlabs/kronk v1.25.2/go.mod h1:b5Gg4jDqvHDklkeHNB8+7treZRxUiCFsV65zphrTloY=
 github.com/atotto/clipboard v0.1.4 h1:EH0zSVneZPSuFR11BlR9YppQTVDbh5+16AmcJi4g1z4=
 github.com/atotto/clipboard v0.1.4/go.mod h1:ZY9tmq7sm5xIbd9bOK4onWV4S6X0u6GY7Vn0Yu86PYI=
-github.com/aws/aws-sdk-go-v2 v1.41.4 h1:10f50G7WyU02T56ox1wWXq+zTX9I1zxG46HYuG1hH/k=
-github.com/aws/aws-sdk-go-v2 v1.41.4/go.mod h1:mwsPRE8ceUUpiTgF7QmQIJ7lgsKUPQOUl3o72QBrE1o=
-github.com/aws/aws-sdk-go-v2/aws/protocol/eventstream v1.7.7 h1:3kGOqnh1pPeddVa/E37XNTaWJ8W6vrbYV9lJEkCnhuY=
-github.com/aws/aws-sdk-go-v2/aws/protocol/eventstream v1.7.7/go.mod h1:lyw7GFp3qENLh7kwzf7iMzAxDn+NzjXEAGjKS2UOKqI=
-github.com/aws/aws-sdk-go-v2/config v1.32.12 h1:O3csC7HUGn2895eNrLytOJQdoL2xyJy0iYXhoZ1OmP0=
-github.com/aws/aws-sdk-go-v2/config v1.32.12/go.mod h1:96zTvoOFR4FURjI+/5wY1vc1ABceROO4lWgWJuxgy0g=
-github.com/aws/aws-sdk-go-v2/credentials v1.19.12 h1:oqtA6v+y5fZg//tcTWahyN9PEn5eDU/Wpvc2+kJ4aY8=
-github.com/aws/aws-sdk-go-v2/credentials v1.19.12/go.mod h1:U3R1RtSHx6NB0DvEQFGyf/0sbrpJrluENHdPy1j/3TE=
-github.com/aws/aws-sdk-go-v2/feature/ec2/imds v1.18.20 h1:zOgq3uezl5nznfoK3ODuqbhVg1JzAGDUhXOsU0IDCAo=
-github.com/aws/aws-sdk-go-v2/feature/ec2/imds v1.18.20/go.mod h1:z/MVwUARehy6GAg/yQ1GO2IMl0k++cu1ohP9zo887wE=
-github.com/aws/aws-sdk-go-v2/internal/configsources v1.4.20 h1:CNXO7mvgThFGqOFgbNAP2nol2qAWBOGfqR/7tQlvLmc=
-github.com/aws/aws-sdk-go-v2/internal/configsources v1.4.20/go.mod h1:oydPDJKcfMhgfcgBUZaG+toBbwy8yPWubJXBVERtI4o=
-github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.7.20 h1:tN6W/hg+pkM+tf9XDkWUbDEjGLb+raoBMFsTodcoYKw=
-github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.7.20/go.mod h1:YJ898MhD067hSHA6xYCx5ts/jEd8BSOLtQDL3iZsvbc=
-github.com/aws/aws-sdk-go-v2/internal/ini v1.8.6 h1:qYQ4pzQ2Oz6WpQ8T3HvGHnZydA72MnLuFK9tJwmrbHw=
-github.com/aws/aws-sdk-go-v2/internal/ini v1.8.6/go.mod h1:O3h0IK87yXci+kg6flUKzJnWeziQUKciKrLjcatSNcY=
-github.com/aws/aws-sdk-go-v2/service/internal/accept-encoding v1.13.7 h1:5EniKhLZe4xzL7a+fU3C2tfUN4nWIqlLesfrjkuPFTY=
-github.com/aws/aws-sdk-go-v2/service/internal/accept-encoding v1.13.7/go.mod h1:x0nZssQ3qZSnIcePWLvcoFisRXJzcTVvYpAAdYX8+GI=
-github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.13.20 h1:2HvVAIq+YqgGotK6EkMf+KIEqTISmTYh5zLpYyeTo1Y=
-github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.13.20/go.mod h1:V4X406Y666khGa8ghKmphma/7C0DAtEQYhkq9z4vpbk=
-github.com/aws/aws-sdk-go-v2/service/signin v1.0.8 h1:0GFOLzEbOyZABS3PhYfBIx2rNBACYcKty+XGkTgw1ow=
-github.com/aws/aws-sdk-go-v2/service/signin v1.0.8/go.mod h1:LXypKvk85AROkKhOG6/YEcHFPoX+prKTowKnVdcaIxE=
-github.com/aws/aws-sdk-go-v2/service/sso v1.30.13 h1:kiIDLZ005EcKomYYITtfsjn7dtOwHDOFy7IbPXKek2o=
-github.com/aws/aws-sdk-go-v2/service/sso v1.30.13/go.mod h1:2h/xGEowcW/g38g06g3KpRWDlT+OTfxxI0o1KqayAB8=
-github.com/aws/aws-sdk-go-v2/service/ssooidc v1.35.17 h1:jzKAXIlhZhJbnYwHbvUQZEB8KfgAEuG0dc08Bkda7NU=
-github.com/aws/aws-sdk-go-v2/service/ssooidc v1.35.17/go.mod h1:Al9fFsXjv4KfbzQHGe6V4NZSZQXecFcvaIF4e70FoRA=
-github.com/aws/aws-sdk-go-v2/service/sts v1.41.9 h1:Cng+OOwCHmFljXIxpEVXAGMnBia8MSU6Ch5i9PgBkcU=
-github.com/aws/aws-sdk-go-v2/service/sts v1.41.9/go.mod h1:LrlIndBDdjA/EeXeyNBle+gyCwTlizzW5ycgWnvIxkk=
-github.com/aws/smithy-go v1.24.2 h1:FzA3bu/nt/vDvmnkg+R8Xl46gmzEDam6mZ1hzmwXFng=
-github.com/aws/smithy-go v1.24.2/go.mod h1:YE2RhdIuDbA5E5bTdciG9KrW3+TiEONeUWCqxX9i1Fc=
+github.com/aws/aws-sdk-go-v2 v1.41.8 h1:sRs7nG6/RiEBZ/K5UO2sNw0w40U02Nmz1VtARloTZXk=
+github.com/aws/aws-sdk-go-v2 v1.41.8/go.mod h1:4LAfZOPHNVNQEckOACQx60Y8pSRjIkNZQz1w92xpMJc=
+github.com/aws/aws-sdk-go-v2/aws/protocol/eventstream v1.7.10 h1:gx1AwW1Iyk9Z9dD9F4akX5gnN3QZwUB20GGKH/I+Rho=
+github.com/aws/aws-sdk-go-v2/aws/protocol/eventstream v1.7.10/go.mod h1:qqY157uZoqm5OXq/amuaBJyC9hgBCBQnsaWnPe905GY=
+github.com/aws/aws-sdk-go-v2/config v1.32.19 h1:qRhIJMbevHUvIE7X4TK8N8zye5+5AhapcslPrvB+qKE=
+github.com/aws/aws-sdk-go-v2/config v1.32.19/go.mod h1:RbJ24nfoya63+Mf5VI+CGCGk9vEdv28xPeii+gojRYs=
+github.com/aws/aws-sdk-go-v2/credentials v1.19.18 h1:GcXQz2M/0ZvMo0v5DakUqbDBeBM1ZNaivkolEF4Esgw=
+github.com/aws/aws-sdk-go-v2/credentials v1.19.18/go.mod h1:sHJ06tMGcD3ZpmMyJqV+VBsGilhSIZPIN+ZFy5Dg0C4=
+github.com/aws/aws-sdk-go-v2/feature/ec2/imds v1.18.24 h1:FQm5ApnyzkuJdXLGskPce83CK1CQKC4RUnIHKVe4BU4=
+github.com/aws/aws-sdk-go-v2/feature/ec2/imds v1.18.24/go.mod h1:JsC7dqQc55MlZ5mvNsDMMge71u8pVcSzU3RNz2h/5yQ=
+github.com/aws/aws-sdk-go-v2/internal/configsources v1.4.24 h1:u6kJU2i0va1AgtJsH3RdWKWqHULlTh7zHwb35Womf74=
+github.com/aws/aws-sdk-go-v2/internal/configsources v1.4.24/go.mod h1:7GY+xLcXOFUpCkNwDReft9qOAVg54A4/AnjHIU7sSAY=
+github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.7.24 h1:Xhbcf3KugX6vX7SDyUK205Oicyfg7EGuvoVNyP5L6DM=
+github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.7.24/go.mod h1:rwDgb2HNOGZsnTHylOUedM7Vnl+bCfnXDqUNPsFWYfk=
+github.com/aws/aws-sdk-go-v2/internal/ini v1.8.0/go.mod h1:8tu/lYfQfFe6IGnaOdrpVgEL2IrrDOf6/m9RQum4NkY=
+github.com/aws/aws-sdk-go-v2/internal/v4a v1.4.25 h1:54CTMmlJ71Rk2dYvM9qZOob+39wjlVja2zDLxCu69Ew=
+github.com/aws/aws-sdk-go-v2/internal/v4a v1.4.25/go.mod h1:BZaHqxsS9vN1fvV5EfEl0OBLOk5+AajWsMu6MjqnZB4=
+github.com/aws/aws-sdk-go-v2/service/internal/accept-encoding v1.13.9 h1:FLudkZLt5ci0ozzgkVo8BJGwvqNaZbTWb3UcucAateA=
+github.com/aws/aws-sdk-go-v2/service/internal/accept-encoding v1.13.9/go.mod h1:w7wZ/s9qK7c8g4al+UyoF1Sp/Z45UwMGcqIzLWVQHWk=
+github.com/aws/aws-sdk-go-v2/service/internal/checksum v1.9.15/go.mod h1:e3IzZvQ3kAWNykvE0Tr0RDZCMFInMvhku3qNpcIQXhM=
+github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.13.24 h1:CQW2FTrflfoslYWLf3fv7vG28Q219+v8YJS5QTQb2+Y=
+github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.13.24/go.mod h1:Xfx13T+u3nH6EEzgl9fBSO6nDRmze1FvnZNYkctQ2zw=
+github.com/aws/aws-sdk-go-v2/service/internal/s3shared v1.19.23/go.mod h1:M8l3mwgx5ToK7wot2sBBce/ojzgnPzZXUV445gTSyE8=
+github.com/aws/aws-sdk-go-v2/service/s3 v1.101.0/go.mod h1:L2dcoOgS2VSgbPLvpak2NyUPsO1TBN7M45Z4H7DlRc4=
+github.com/aws/aws-sdk-go-v2/service/signin v1.1.0 h1:yQo3eZ5qFaL1sJWqs1nL6j3yPHA2/R7c6tQ4T+0IO10=
+github.com/aws/aws-sdk-go-v2/service/signin v1.1.0/go.mod h1:3Zzou41Qt/ueXfIzHvTEjDNuR5IjCUBVF01SNhrt1e8=
+github.com/aws/aws-sdk-go-v2/service/sso v1.30.18 h1:ApLTFdAZfDhZSiY5uskwECKHkSNNF83y2Ru2r7SezWA=
+github.com/aws/aws-sdk-go-v2/service/sso v1.30.18/go.mod h1:A9K9qx2l6nK89hp+a350FdGfRkrkH5HdiEjHbiy/Q/c=
+github.com/aws/aws-sdk-go-v2/service/ssooidc v1.36.1 h1:4VD7TIZOGzehrgQ8vDE+1c6BQW4ErZPGY8ohZT5LXEE=
+github.com/aws/aws-sdk-go-v2/service/ssooidc v1.36.1/go.mod h1:er0SFJfdV89Rit5hIJu/EXtv+qC2XMnxoksLmcUFkqM=
+github.com/aws/aws-sdk-go-v2/service/sts v1.42.2 h1:XKnxlM4KZH1gktcsh3zSWc7GW4KivEv/OkifmHOhCUY=
+github.com/aws/aws-sdk-go-v2/service/sts v1.42.2/go.mod h1:KJYmkQaFB3SUW2j3aBkPsxNmAb4ZsSOvbvCpuxzHJA0=
+github.com/aws/smithy-go v1.26.0 h1:9ouqbi+NyKP7fV3Te7UElCwdAb6Y8uk7LGwPE5tVe/s=
+github.com/aws/smithy-go v1.26.0/go.mod h1:YE2RhdIuDbA5E5bTdciG9KrW3+TiEONeUWCqxX9i1Fc=
 github.com/aymanbagabas/go-osc52/v2 v2.0.1 h1:HwpRHbFMcZLEVr42D4p7XBqjyuxQH5SMiErDT4WkJ2k=
 github.com/aymanbagabas/go-osc52/v2 v2.0.1/go.mod h1:uYgXzlJ7ZpABp8OJ+exZzJJhRNQ2ASbcXHWsFqH8hp8=
 github.com/aymanbagabas/go-udiff v0.4.1 h1:OEIrQ8maEeDBXQDoGCbbTTXYJMYRCRO1fnodZ12Gv5o=
 github.com/aymanbagabas/go-udiff v0.4.1/go.mod h1:0L9PGwj20lrtmEMeyw4WKJ/TMyDtvAoK9bf2u/mNo3w=
-github.com/aymerick/douceur v0.2.0 h1:Mv+mAeH1Q+n9Fr+oyamOlAkUNPWPlA8PPGR0QAaYuPk=
-github.com/aymerick/douceur v0.2.0/go.mod h1:wlT5vV2O3h55X9m7iVYN0TBM0NH/MmbLnd30/FjWUq4=
-github.com/bahlo/generic-list-go v0.2.0 h1:5sz/EEAK+ls5wF+NeqDpk5+iNdMDXrh3z3nPnH1Wvgk=
 github.com/bahlo/generic-list-go v0.2.0/go.mod h1:2KvAjgMlE5NNynlg/5iLrrCCZ2+5xWbdbCW3pNTGyYg=
-github.com/buger/jsonparser v1.1.2 h1:frqHqw7otoVbk5M8LlE/L7HTnIq2v9RX6EJ48i9AxJk=
-github.com/buger/jsonparser v1.1.2/go.mod h1:6RYKKt7H4d4+iWqouImQ9R2FZql3VbhNgx27UK13J/0=
+github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
+github.com/bgentry/go-netrc v0.0.0-20140422174119-9fd32a8b3d3d/go.mod h1:6QX/PXZ00z/TKoufEY6K/a0k6AhaJrQKdFe6OfVXsa4=
+github.com/bits-and-blooms/bitset v1.24.4/go.mod h1:7hO7Gc7Pp1vODcmWvKMRA9BNmbv6a/7QIWpPxHddWR8=
+github.com/buger/jsonparser v1.1.1/go.mod h1:6RYKKt7H4d4+iWqouImQ9R2FZql3VbhNgx27UK13J/0=
 github.com/catppuccin/go v0.3.0 h1:d+0/YicIq+hSTo5oPuRi5kOpqkVA5tAsU6dNhvRu+aY=
 github.com/catppuccin/go v0.3.0/go.mod h1:8IHJuMGaUUjQM82qBrGNBv7LFq6JI3NnQCF6MOlZjpc=
+github.com/cenkalti/backoff/v5 v5.0.3/go.mod h1:rkhZdG3JZukswDf7f0cwqPNk4K0sa+F97BxZthm/crw=
 github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
 github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/charmbracelet/anthropic-sdk-go v0.0.0-20260223140439-63879b0b8dab h1:J7XQLgl9sefgTnTGrmX3xqvp5o6MCiBzEjGv5igAlc4=
@@ -84,8 +101,6 @@ github.com/charmbracelet/colorprofile v0.4.3 h1:QPa1IWkYI+AOB+fE+mg/5/4HRMZcaXex
 github.com/charmbracelet/colorprofile v0.4.3/go.mod h1:/zT4BhpD5aGFpqQQqw7a+VtHCzu+zrQtt1zhMt9mR4Q=
 github.com/charmbracelet/fang v1.0.0 h1:jESBY40agJOlLYnnv9jE0mLqDGTxEk0hkOnx7YGyRlQ=
 github.com/charmbracelet/fang v1.0.0/go.mod h1:P5/DNb9DddQ0Z0dbc0P3ol4/ix5Po7Ofr2KMBfAqoCo=
-github.com/charmbracelet/glamour v1.0.0 h1:AWMLOVFHTsysl4WV8T8QgkQ0s/ZNZo7CiE4WKhk8l08=
-github.com/charmbracelet/glamour v1.0.0/go.mod h1:DSdohgOBkMr2ZQNhw4LZxSGpx3SvpeujNoXrQyH2hxo=
 github.com/charmbracelet/harmonica v0.2.0 h1:8NxJWRWg/bzKqqEaaeFNipOu77YR5t8aSwG4pgaUBiQ=
 github.com/charmbracelet/harmonica v0.2.0/go.mod h1:KSri/1RMQOZLbw7AHqgcBycp8pgJnQMYYT8QZRqZ1Ao=
 github.com/charmbracelet/lipgloss v1.1.1-0.20250404203927-76690c660834 h1:ZR7e0ro+SZZiIZD7msJyA+NjkCNNavuiPBLgerbOziE=
@@ -94,24 +109,26 @@ github.com/charmbracelet/log v1.0.0 h1:HVVVMmfOorfj3BA9i8X8UL69Hoz9lI0PYwXfJvOdR
 github.com/charmbracelet/log v1.0.0/go.mod h1:uYgY3SmLpwJWxmlrPwXvzVYujxis1vAKRV/0VQB7yWA=
 github.com/charmbracelet/openai-go v0.0.0-20260319145158-d0740cc34266 h1:BW/sZtyd1JyYy0h5adMm3tzpNyL857LWjuTRET6OhpY=
 github.com/charmbracelet/openai-go v0.0.0-20260319145158-d0740cc34266/go.mod h1:1DahUaExbUZx/jD+FNT2PKP4L9rLE5+ZBRuI8mZjd/E=
-github.com/charmbracelet/ultraviolet v0.0.0-20260316091819-b93f6a3b8502 h1:hzWNs3UQRSUTS6YCbLaQnwqKBFXT5Yh1OOw6+26apqg=
-github.com/charmbracelet/ultraviolet v0.0.0-20260316091819-b93f6a3b8502/go.mod h1:mkUCcxn9w9j89JJp3pOza5tmDQZPgIB75UfmQlFYvas=
-github.com/charmbracelet/x/ansi v0.11.6 h1:GhV21SiDz/45W9AnV2R61xZMRri5NlLnl6CVF7ihZW8=
-github.com/charmbracelet/x/ansi v0.11.6/go.mod h1:2JNYLgQUsyqaiLovhU2Rv/pb8r6ydXKS3NIttu3VGZQ=
+github.com/charmbracelet/ultraviolet v0.0.0-20260601155805-6cf7526a1b3f h1:vKsPSlO4g4jKfJ9enESgNZ45BkbHngTIq3UxNOzic74=
+github.com/charmbracelet/ultraviolet v0.0.0-20260601155805-6cf7526a1b3f/go.mod h1:hFpumms29Smx3LStRfku8vcCTBe1Kq8aCXtHUJa3mjY=
+github.com/charmbracelet/x/ansi v0.11.7 h1:kzv1kJvjg2S3r9KHo8hDdHFQLEqn4RBCb39dAYC84jI=
+github.com/charmbracelet/x/ansi v0.11.7/go.mod h1:9qGpnAVYz+8ACONkZBUWPtL7lulP9No6p1epAihUZwQ=
 github.com/charmbracelet/x/cellbuf v0.0.15 h1:ur3pZy0o6z/R7EylET877CBxaiE1Sp1GMxoFPAIztPI=
 github.com/charmbracelet/x/cellbuf v0.0.15/go.mod h1:J1YVbR7MUuEGIFPCaaZ96KDl5NoS0DAWkskup+mOY+Q=
 github.com/charmbracelet/x/conpty v0.1.1 h1:s1bUxjoi7EpqiXysVtC+a8RrvPPNcNvAjfi4jxsAuEs=
 github.com/charmbracelet/x/conpty v0.1.1/go.mod h1:OmtR77VODEFbiTzGE9G1XiRJAga6011PIm4u5fTNZpk=
+github.com/charmbracelet/x/editor v0.2.0 h1:7XLUKtaRaB8jN7bWU2p2UChiySyaAuIfYiIRg8gGWwk=
+github.com/charmbracelet/x/editor v0.2.0/go.mod h1:p3oQ28TSL3YPd+GKJ1fHWcp+7bVGpedHpXmo0D6t1dY=
 github.com/charmbracelet/x/errors v0.0.0-20240508181413-e8d8b6e2de86 h1:JSt3B+U9iqk37QUU2Rvb6DSBYRLtWqFqfxf8l5hOZUA=
 github.com/charmbracelet/x/errors v0.0.0-20240508181413-e8d8b6e2de86/go.mod h1:2P0UgXMEa6TsToMSuFqKFQR+fZTO9CNGUNokkPatT/0=
-github.com/charmbracelet/x/exp/charmtone v0.0.0-20260322003602-9b007323c5cd h1:eStB6uX52pgrm6TxQcEKctPrEC+a/9ubJC+P671idOc=
-github.com/charmbracelet/x/exp/charmtone v0.0.0-20260322003602-9b007323c5cd/go.mod h1:nsExn0DGyX0lh9LwLHTn2Gg+hafdzfSXnC+QmEJTZFY=
+github.com/charmbracelet/x/exp/charmtone v0.0.0-20260602025833-85a30b5e440a h1:aVvnksCVgxB2igk7jERL9ARIkbDXccp1gXCFqhGlamQ=
+github.com/charmbracelet/x/exp/charmtone v0.0.0-20260602025833-85a30b5e440a/go.mod h1:nsExn0DGyX0lh9LwLHTn2Gg+hafdzfSXnC+QmEJTZFY=
 github.com/charmbracelet/x/exp/golden v0.0.0-20250806222409-83e3a29d542f h1:pk6gmGpCE7F3FcjaOEKYriCvpmIN4+6OS/RD0vm4uIA=
 github.com/charmbracelet/x/exp/golden v0.0.0-20250806222409-83e3a29d542f/go.mod h1:IfZAMTHB6XkZSeXUqriemErjAWCCzT0LwjKFYCZyw0I=
 github.com/charmbracelet/x/exp/ordered v0.1.0 h1:55/qLwjIh0gL0Vni+QAWk7T/qRVP6sBf+2agPBgnOFE=
 github.com/charmbracelet/x/exp/ordered v0.1.0/go.mod h1:5UHwmG+is5THxMyCJHNPCn2/ecI07aKNrW+LcResjJ8=
-github.com/charmbracelet/x/exp/slice v0.0.0-20260322003602-9b007323c5cd h1:U8xj0UXwqHzO+UYHZJopKF+gWaQEW8oj60fmiq9TFY4=
-github.com/charmbracelet/x/exp/slice v0.0.0-20260322003602-9b007323c5cd/go.mod h1:vqEfX6xzqW1pKKZUUiFOKg0OQ7bCh54Q2vR/tserrRA=
+github.com/charmbracelet/x/exp/slice v0.0.0-20260527151214-009e6338d40d h1:RxcAR+vJCoD8QqT1cqLtkQKw+1cqvjqnu5IpPqYzPco=
+github.com/charmbracelet/x/exp/slice v0.0.0-20260527151214-009e6338d40d/go.mod h1:vqEfX6xzqW1pKKZUUiFOKg0OQ7bCh54Q2vR/tserrRA=
 github.com/charmbracelet/x/exp/strings v0.1.0 h1:i69S2XI7uG1u4NLGeJPSYU++Nmjvpo9nwd6aoEm7gkA=
 github.com/charmbracelet/x/exp/strings v0.1.0/go.mod h1:/ehtMPNh9K4odGFkqYJKpIYyePhdp1hLBRvyY4bWkH8=
 github.com/charmbracelet/x/json v0.2.0 h1:DqB+ZGx2h+Z+1s98HOuOyli+i97wsFQIxP2ZQANTPrQ=
@@ -126,36 +143,45 @@ github.com/charmbracelet/x/xpty v0.1.3 h1:eGSitii4suhzrISYH50ZfufV3v085BXQwIytcO
 github.com/charmbracelet/x/xpty v0.1.3/go.mod h1:poPYpWuLDBFCKmKLDnhBp51ATa0ooD8FhypRwEFtH3Y=
 github.com/clipperhouse/displaywidth v0.11.0 h1:lBc6kY44VFw+TDx4I8opi/EtL9m20WSEFgwIwO+UVM8=
 github.com/clipperhouse/displaywidth v0.11.0/go.mod h1:bkrFNkf81G8HyVqmKGxsPufD3JhNl3dSqnGhOoSD/o0=
+github.com/clipperhouse/stringish v0.1.1/go.mod h1:v/WhFtE1q0ovMta2+m+UbpZ+2/HEXNWYXQgCt4hdOzA=
 github.com/clipperhouse/uax29/v2 v2.7.0 h1:+gs4oBZ2gPfVrKPthwbMzWZDaAFPGYK72F0NJv2v7Vk=
 github.com/clipperhouse/uax29/v2 v2.7.0/go.mod h1:EFJ2TJMRUaplDxHKj1qAEhCtQPW2tJSwu5BF98AuoVM=
 github.com/cncf/xds/go v0.0.0-20260202195803-dba9d589def2 h1:aBangftG7EVZoUb69Os8IaYg++6uMOdKK83QtkkvJik=
 github.com/cncf/xds/go v0.0.0-20260202195803-dba9d589def2/go.mod h1:qwXFYgsP6T7XnJtbKlf1HP8AjxZZyzxMmc+Lq5GjlU4=
-github.com/coder/acp-go-sdk v0.6.3 h1:LsXQytehdjKIYJnoVWON/nf7mqbiarnyuyE3rrjBsXQ=
-github.com/coder/acp-go-sdk v0.6.3/go.mod h1:yKzM/3R9uELp4+nBAwwtkS0aN1FOFjo11CNPy37yFko=
+github.com/coder/acp-go-sdk v0.13.5 h1:LI9jq5xon7xslaYlnoktvTVyDlE37yIk2daT7N9ASYk=
+github.com/coder/acp-go-sdk v0.13.5/go.mod h1:yKzM/3R9uELp4+nBAwwtkS0aN1FOFjo11CNPy37yFko=
 github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
 github.com/creack/pty v1.1.24 h1:bJrF4RRfyJnbTJqzRLHzcGaZK1NeM5kTC9jGgovnR1s=
 github.com/creack/pty v1.1.24/go.mod h1:08sCNb52WyoAwi2QDyzUCTgcvVFhUzewun7wtTfvcwE=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc h1:U9qPSI2PIWSS1VwoXQT9A3Wy9MM3WgvqSxFWenqJduM=
 github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/dlclark/regexp2 v1.11.5 h1:Q/sSnsKerHeCkc/jSTNq1oCm7KiVgUMZRDUoRu0JQZQ=
-github.com/dlclark/regexp2 v1.11.5/go.mod h1:DHkYz0B9wPfa6wondMfaivmHpzrQ3v9q8cnmRbL6yW8=
+github.com/dlclark/regexp2 v1.12.0 h1:0j4c5qQmnC6XOWNjP3PIXURXN2gWx76rd3KvgdPkCz8=
+github.com/dlclark/regexp2 v1.12.0/go.mod h1:DHkYz0B9wPfa6wondMfaivmHpzrQ3v9q8cnmRbL6yW8=
+github.com/dlclark/regexp2/v2 v2.1.1 h1:LCUGyd9Wf+r+VVOl8Ny38JTpWJcAsdVnCIuhhtthmKw=
+github.com/dlclark/regexp2/v2 v2.1.1/go.mod h1:avUrQvPaLz2DrFNHJF0taWAFFX2C1GMSSoeiqFjcBmU=
 github.com/dnaeon/go-vcr v1.2.0 h1:zHCHvJYTMh1N7xnV7zf1m1GPBF9Ad0Jk/whtQ1663qI=
 github.com/dnaeon/go-vcr v1.2.0/go.mod h1:R4UdLID7HZT3taECzJs4YgbbH6PIGXB6W/sc5OLb6RQ=
+github.com/dromara/carbon/v2 v2.6.16/go.mod h1:NGo3reeV5vhWCYWcSqbJRZm46MEwyfYI5EJRdVFoLJo=
 github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkpeCY=
 github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=
+github.com/ebitengine/purego v0.10.0/go.mod h1:iIjxzd6CiRiOG0UyXP+V1+jWqUXVjPKLAI0mRfJZTmQ=
+github.com/eliben/go-sentencepiece v0.6.0/go.mod h1:nNYk4aMzgBoI6QFp4LUG8Eu1uO9fHD9L5ZEre93o9+c=
 github.com/envoyproxy/go-control-plane v0.14.0 h1:hbG2kr4RuFj222B6+7T83thSPqLjwBIfQawTkC++2HA=
+github.com/envoyproxy/go-control-plane v0.14.0/go.mod h1:NcS5X47pLl/hfqxU70yPwL9ZMkUlwlKxtAohpi2wBEU=
 github.com/envoyproxy/go-control-plane/envoy v1.37.0 h1:u3riX6BoYRfF4Dr7dwSOroNfdSbEPe9Yyl09/B6wBrQ=
 github.com/envoyproxy/go-control-plane/envoy v1.37.0/go.mod h1:DReE9MMrmecPy+YvQOAOHNYMALuowAnbjjEMkkWOi6A=
+github.com/envoyproxy/go-control-plane/ratelimit v0.1.0/go.mod h1:Wk+tMFAFbCXaJPzVVHnPgRKdUdwW/KdbRt94AzgRee4=
 github.com/envoyproxy/protoc-gen-validate v1.3.3 h1:MVQghNeW+LZcmXe7SY1V36Z+WFMDjpqGAGacLe2T0ds=
 github.com/envoyproxy/protoc-gen-validate v1.3.3/go.mod h1:TsndJ/ngyIdQRhMcVVGDDHINPLWB7C82oDArY51KfB0=
 github.com/felixge/httpsnoop v1.0.4 h1:NFTV2Zj1bL4mc9sqWACXbQFVBBg2W3GPvqp8/ESS2Wg=
 github.com/felixge/httpsnoop v1.0.4/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
 github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHkI4W8=
 github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
-github.com/fsnotify/fsnotify v1.9.0 h1:2Ml+OJNzbYCTzsxtv8vKSFD9PbJjmhYF14k/jKC7S9k=
-github.com/fsnotify/fsnotify v1.9.0/go.mod h1:8jBTzvmWwFyi3Pb8djgCCO5IBqzKJ/Jwo8TRcHyHii0=
-github.com/go-json-experiment/json v0.0.0-20260214004413-d219187c3433 h1:vymEbVwYFP/L05h5TKQxvkXoKxNvTpjxYKdF1Nlwuao=
-github.com/go-json-experiment/json v0.0.0-20260214004413-d219187c3433/go.mod h1:tphK2c80bpPhMOI4v6bIc2xWywPfbqi1Z06+RcrMkDg=
+github.com/fsnotify/fsnotify v1.10.1 h1:b0/UzAf9yR5rhf3RPm9gf3ehBPpf0oZKIjtpKrx59Ho=
+github.com/fsnotify/fsnotify v1.10.1/go.mod h1:TLheqan6HD6GBK6PrDWyDPBaEV8LspOxvPSjC+bVfgo=
+github.com/go-jose/go-jose/v4 v4.1.4/go.mod h1:x4oUasVrzR7071A4TnHLGSPpNOm2a21K9Kf04k1rs08=
+github.com/go-json-experiment/json v0.0.0-20260520185125-572e7c383686 h1:NZBJxCpbHS1gzS6xAmyxbJznosZIIPk9IB42v62UvKA=
+github.com/go-json-experiment/json v0.0.0-20260520185125-572e7c383686/go.mod h1:tphK2c80bpPhMOI4v6bIc2xWywPfbqi1Z06+RcrMkDg=
 github.com/go-logfmt/logfmt v0.6.1 h1:4hvbpePJKnIzH1B+8OR/JPbTx37NktoI9LE2QZBBkvE=
 github.com/go-logfmt/logfmt v0.6.1/go.mod h1:EV2pOAQoZaT1ZXZbqDl5hrymndi4SY9ED9/z6CO0XAk=
 github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
@@ -169,55 +195,69 @@ github.com/goccy/go-yaml v1.19.2 h1:PmFC1S6h8ljIz6gMRBopkjP1TVT7xuwrButHID66PoM=
 github.com/goccy/go-yaml v1.19.2/go.mod h1:XBurs7gK8ATbW4ZPGKgcbrY1Br56PdM69F7LkFRi1kA=
 github.com/golang-jwt/jwt/v5 v5.3.0 h1:pv4AsKCKKZuqlgs5sUmn4x8UlGa0kEVt/puTpKx9vvo=
 github.com/golang-jwt/jwt/v5 v5.3.0/go.mod h1:fxCRLWMO43lRc8nhHWY6LGqRcf+1gQWArsqaEUEa5bE=
+github.com/golang/glog v1.2.5/go.mod h1:6AhwSGph0fcJtXVM/PEHPqZlFeoLxhs7/t5UDAwmO+w=
+github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
 github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
 github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
+github.com/golang/snappy v0.0.4/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
 github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
 github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
+github.com/google/go-pkcs11 v0.3.0/go.mod h1:6eQoGcuNJpa7jnd5pMGdkSaQpNDYvPlXWMcjXXThLlY=
+github.com/google/jsonschema-go v0.4.3 h1:/DBOLZTfDow7pe2GmaJNhltueGTtDKICi8V8p+DQPd0=
+github.com/google/jsonschema-go v0.4.3/go.mod h1:r5quNTdLOYEz95Ru18zA0ydNbBuYoo9tgaYcxEYhJVE=
+github.com/google/martian/v3 v3.3.3/go.mod h1:iEPrYcgCF7jA9OtScMFQyAlZZ4YXTKEtJ1E6RWzmBA0=
 github.com/google/s2a-go v0.1.9 h1:LGD7gtMgezd8a/Xak7mEWL0PjoTQFvpRudN895yqKW0=
 github.com/google/s2a-go v0.1.9/go.mod h1:YA0Ei2ZQL3acow2O62kdp9UlnvMmU7kA6Eutn0dXayM=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
-github.com/googleapis/enterprise-certificate-proxy v0.3.14 h1:yh8ncqsbUY4shRD5dA6RlzjJaT4hi3kII+zYw8wmLb8=
-github.com/googleapis/enterprise-certificate-proxy v0.3.14/go.mod h1:vqVt9yG9480NtzREnTlmGSBmFrA+bzb0yl0TxoBQXOg=
-github.com/googleapis/gax-go/v2 v2.19.0 h1:fYQaUOiGwll0cGj7jmHT/0nPlcrZDFPrZRhTsoCr8hE=
-github.com/googleapis/gax-go/v2 v2.19.0/go.mod h1:w2ROXVdfGEVFXzmlciUU4EdjHgWvB5h2n6x/8XSTTJA=
-github.com/gorilla/css v1.0.1 h1:ntNaBIghp6JmvWnxbZKANoLyuXTPZ4cAMlo6RyhlbO8=
-github.com/gorilla/css v1.0.1/go.mod h1:BvnYkspnSzMmwRK+b8/xgNPLiIuNZr6vbZBTPQ2A3b0=
+github.com/googleapis/enterprise-certificate-proxy v0.3.16 h1:F/VPrx0YPBdksZJQdCAp0WUsqnNmZpUZszzfYt0M5Dw=
+github.com/googleapis/enterprise-certificate-proxy v0.3.16/go.mod h1:9Yb0eAkH/Xqhvv3zbeKf/+wMJqCeocWc6KIhDvEAuYE=
+github.com/googleapis/gax-go/v2 v2.22.0 h1:PjIWBpgGIVKGoCXuiCoP64altEJCj3/Ei+kSU5vlZD4=
+github.com/googleapis/gax-go/v2 v2.22.0/go.mod h1:irWBbALSr0Sk3qlqb9SyJ1h68WjgeFuiOzI4Rqw5+aY=
 github.com/gorilla/websocket v1.5.3 h1:saDtZ6Pbx/0u+bgYQ3q96pZgCzfhKXGPqt7kZ72aNNg=
 github.com/gorilla/websocket v1.5.3/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
+github.com/grpc-ecosystem/grpc-gateway/v2 v2.29.0/go.mod h1:Hyl3n6Twe1hvtd9XUXDec4pTvgMSEixRuQKPTMH2bNs=
+github.com/hashicorp/aws-sdk-go-base/v2 v2.0.0-beta.72/go.mod h1:Vn+BBgKQHVQYdVQ4NZDICE1Brb+JfaONyDHr3q07oQc=
+github.com/hashicorp/go-cleanhttp v0.5.2/go.mod h1:kO/YDlP8L1346E6Sodw+PrpBSV4/SoxCXGY6BqNFT48=
+github.com/hashicorp/go-getter v1.8.6/go.mod h1:nVH12eOV2P58dIiL3rsU6Fh3wLeJEKBOJzhMmzlSWoo=
+github.com/hashicorp/go-version v1.9.0/go.mod h1:fltr4n8CU8Ke44wwGCBoEymUuxUHl09ZGVZPK5anwXA=
 github.com/hexops/gotextdiff v1.0.3 h1:gitA9+qJrrTCsiCl7+kh75nPqQt1cx4ZkudSTLoUqJM=
 github.com/hexops/gotextdiff v1.0.3/go.mod h1:pSWU5MAI3yDq+fZBTazCSJysOMbxWL1BSow5/V2vxeg=
+github.com/hybridgroup/yzma v1.13.0/go.mod h1:zrzMgv/KVQz23+s6l16b+vJ+9uJVBdWtGcGkwRTMeiQ=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
-github.com/invopop/jsonschema v0.13.0 h1:KvpoAJWEjR3uD9Kbm2HWJmqsEaHt8lBUpd0qHcIi21E=
+github.com/indaco/herald v0.13.0 h1:+xVG9Fx5NpuWhwku/9IlRL6I009NnX4VUGKvlZHTRxU=
+github.com/indaco/herald v0.13.0/go.mod h1:T5g1+XLYvpjouhzAGHnAHDCKizhESkoV6+QPZ3DhgWA=
+github.com/indaco/herald-md v0.3.0 h1:hN1cKyrexPPM9PeHBsKuaWvIizSi/iYvM9yzRgtdb8M=
+github.com/indaco/herald-md v0.3.0/go.mod h1:RUHVaDSG45ymJjKyxpDwBocLXrZo93FB4OeYMsw9B9s=
 github.com/invopop/jsonschema v0.13.0/go.mod h1:ffZ5Km5SWWRAIN6wbDXItl95euhFz2uON45H2qjYt+0=
-github.com/kaptinlin/go-i18n v0.2.12 h1:ywDsvb4KDFddMC2dpI/rrIzGU2mWUSvHmWUm9BMsdl4=
-github.com/kaptinlin/go-i18n v0.2.12/go.mod h1:pVcu9qsW5pOIOoZFJXesRYmLos1vMQrby70JPAoWmJU=
-github.com/kaptinlin/jsonpointer v0.4.17 h1:mY9k8ciWncxbsECyaxKnR0MdmxamNdp2tLQkAKVrtSk=
-github.com/kaptinlin/jsonpointer v0.4.17/go.mod h1:SsfsjqnHG5zuKo1DTBzk1VknaHlL4osHw+X9kZKukpU=
-github.com/kaptinlin/jsonschema v0.7.6 h1:UUMqZGFAk7nOzQsYAxvgygm4wpDp/nwXxA4VP9mCPCs=
-github.com/kaptinlin/jsonschema v0.7.6/go.mod h1:GGk/oE+F1lWUfYrzKaCf4QWZmMdytt0LL4XdFEFB0LE=
-github.com/kaptinlin/messageformat-go v0.4.18 h1:RBlHVWgZyoxTcUgGWBsl2AcyScq/urqbLZvzgryTmSI=
-github.com/kaptinlin/messageformat-go v0.4.18/go.mod h1:ntI3154RnqJgr7GaC+vZBnIExl2V3sv9selvRNNEM24=
+github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=
+github.com/jupiterrider/ffi v0.7.0/go.mod h1:9dauhpOfNqrqk28fxuu0kkdeFtT9Qr4vbfigiuIXN7c=
+github.com/kaptinlin/go-i18n v0.4.5 h1:9tIlo5A0RXth+yZJO2MG7Bhpu/X9PlzQnGz/qyYWNoY=
+github.com/kaptinlin/go-i18n v0.4.5/go.mod h1:mU/7BH4molY5lGZYBwBRKAaiJ70dWRHuqmQ0/pFLGno=
+github.com/kaptinlin/jsonpointer v0.4.25 h1:iJ197e8n+WwqaqBsa53FqG3rPJCg5oijyFXEXNWWC3E=
+github.com/kaptinlin/jsonpointer v0.4.25/go.mod h1:wVOBaXGGnP42YsMb6zev/3W5POTvspdNfh8DXzf8XS8=
+github.com/kaptinlin/jsonschema v0.7.13 h1:kahVXTy/rURL0XJjyQ9WELm59wEmXi6IY0TWswQEFvU=
+github.com/kaptinlin/jsonschema v0.7.13/go.mod h1:Uh0aUBusnhXDCEXJ2oimL/hx7YTo7F+sKniE+tM0ERc=
+github.com/kaptinlin/messageformat-go v0.6.0 h1:D6jiXFsKW4/JG2CMddv/F6Rev9KVbCRKEzzV5QOAcpc=
+github.com/kaptinlin/messageformat-go v0.6.0/go.mod h1:NKjwS6e9u7DRhAK+vydjDDwJ7UbdHhYjk/yk2WPuZPs=
+github.com/klauspost/compress v1.18.6/go.mod h1:cwPg85FWrGar70rWktvGQj8/hthj3wpl0PGDogxkrSQ=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0SNc=
 github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=
-github.com/lucasb-eyer/go-colorful v1.3.0 h1:2/yBRLdWBZKrf7gB40FoiKfAWYQ0lqNcbuQwVHXptag=
-github.com/lucasb-eyer/go-colorful v1.3.0/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
-github.com/mailru/easyjson v0.9.2 h1:dX8U45hQsZpxd80nLvDGihsQ/OxlvTkVUXH2r/8cb2M=
-github.com/mailru/easyjson v0.9.2/go.mod h1:1+xMtQp2MRNVL/V1bOzuP3aP8VNwRW55fQUto+XFtTU=
-github.com/mark3labs/mcp-go v0.45.0 h1:s0S8qR/9fWaQ3pHxz7pm1uQ0DrswoSnRIxKIjbiQtkc=
-github.com/mark3labs/mcp-go v0.45.0/go.mod h1:YnJfOL382MIWDx1kMY+2zsRHU/q78dBg9aFb8W6Thdw=
-github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
-github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
-github.com/mattn/go-runewidth v0.0.12/go.mod h1:RAqKPSqVFrSLVXbA8x7dzmKdmGzieGRCM46jaSJTDAk=
-github.com/mattn/go-runewidth v0.0.21 h1:jJKAZiQH+2mIinzCJIaIG9Be1+0NR+5sz/lYEEjdM8w=
-github.com/mattn/go-runewidth v0.0.21/go.mod h1:XBkDxAl56ILZc9knddidhrOlY5R/pDhgLpndooCuJAs=
-github.com/microcosm-cc/bluemonday v1.0.27 h1:MpEUotklkwCSLeH+Qdx1VJgNqLlpY2KXwXFM08ygZfk=
-github.com/microcosm-cc/bluemonday v1.0.27/go.mod h1:jFi9vgW+H7c3V0lb6nR74Ib/DIB5OBs92Dimizgw2cA=
+github.com/lucasb-eyer/go-colorful v1.4.0 h1:UtrWVfLdarDgc44HcS7pYloGHJUjHV/4FwW4TvVgFr4=
+github.com/lucasb-eyer/go-colorful v1.4.0/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
+github.com/mailru/easyjson v0.7.7/go.mod h1:xzfreul335JAWq5oZzymOObrkdz5UnU4kGfJJLY9Nlc=
+github.com/mark3labs/mcp-go v0.54.1 h1:Ap/ptEB9FtWzFKM8NDsTA7QDxerQOC06eZigrTldVj0=
+github.com/mark3labs/mcp-go v0.54.1/go.mod h1:+8WclSK1ZUweCP3hvktSji8n8ABG/95QaEkeVE/Uwas=
+github.com/mattn/go-isatty v0.0.22 h1:j8l17JJ9i6VGPUFUYoTUKPSgKe/83EYU2zBC7YNKMw4=
+github.com/mattn/go-isatty v0.0.22/go.mod h1:ZXfXG4SQHsB/w3ZeOYbR0PrPwLy+n6xiMrJlRFqopa4=
+github.com/mattn/go-runewidth v0.0.24 h1:cpokDiIn0MGnhdHwuWnJBITySJ20QyNGnY2kR/ay2DU=
+github.com/mattn/go-runewidth v0.0.24/go.mod h1:XBkDxAl56ILZc9knddidhrOlY5R/pDhgLpndooCuJAs=
+github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
 github.com/mitchellh/hashstructure/v2 v2.0.2 h1:vGKWl0YJqUNxE8d+h8f6NJLcCJrgbhC4NcD46KavDd4=
 github.com/mitchellh/hashstructure/v2 v2.0.2/go.mod h1:MG3aRVU/N29oo/V/IhBX8GR/zz4kQkprJgF2EVszyDE=
 github.com/muesli/cancelreader v0.2.2 h1:3I4Kt4BQjOR54NavqnDogx/MIoWBFa0StPA8ELUXHmA=
@@ -228,22 +268,23 @@ github.com/muesli/mango-cobra v1.3.0 h1:vQy5GvPg3ndOSpduxutqFoINhWk3vD5K2dXo5E8p
 github.com/muesli/mango-cobra v1.3.0/go.mod h1:Cj1ZrBu3806Qw7UjxnAUgE+7tllUBj1NCLQDwwGx19E=
 github.com/muesli/mango-pflag v0.2.0 h1:QViokgKDZQCzKhYe1zH8D+UlPJzBSGoP9yx0hBG0t5k=
 github.com/muesli/mango-pflag v0.2.0/go.mod h1:X9LT1p/pbGA1wjvEbtwnixujKErkP0jVmrxwrw3fL0Y=
-github.com/muesli/reflow v0.3.0 h1:IFsN6K9NfGtjeggFP+68I4chLZV2yIKsXJFNZ+eWh6s=
-github.com/muesli/reflow v0.3.0/go.mod h1:pbwTDkVPibjO2kyvBQRBxTWEEGDGq0FlB1BIKtnHY/8=
 github.com/muesli/roff v0.1.0 h1:YD0lalCotmYuF5HhZliKWlIx7IEhiXeSfq7hNjFqGF8=
 github.com/muesli/roff v0.1.0/go.mod h1:pjAHQM9hdUUwm/krAfrLGgJkXJ+YuhtsfZ42kieB2Ig=
 github.com/muesli/termenv v0.16.0 h1:S5AlUN9dENB57rsbnkPyfdGuWIlkmzJjbFf0Tf5FWUc=
 github.com/muesli/termenv v0.16.0/go.mod h1:ZRfOIKPFDYQoDFF4Olj7/QJbW60Ol/kL1pU3VfY/Cnk=
-github.com/pelletier/go-toml/v2 v2.2.4 h1:mye9XuhQ6gvn5h28+VilKrrPoQVanw5PMw/TB0t5Ec4=
-github.com/pelletier/go-toml/v2 v2.2.4/go.mod h1:2gIqNv+qfxSVS7cM2xJQKtLSTLUE9V8t9Stt+h56mCY=
+github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
+github.com/pelletier/go-toml/v2 v2.3.1 h1:MYEvvGnQjeNkRF1qUuGolNtNExTDwct51yp7olPtrEc=
+github.com/pelletier/go-toml/v2 v2.3.1/go.mod h1:2gIqNv+qfxSVS7cM2xJQKtLSTLUE9V8t9Stt+h56mCY=
 github.com/pkg/browser v0.0.0-20240102092130-5ac0b6a4141c h1:+mdjkGKdHQG3305AYmdv1U2eRNDiU2ErMBj1gwrq8eQ=
 github.com/pkg/browser v0.0.0-20240102092130-5ac0b6a4141c/go.mod h1:7rwL4CYBLnjLxUqIJNnCWiEdr3bn6IUYi15bNlnbCCU=
 github.com/planetscale/vtprotobuf v0.6.1-0.20240319094008-0393e58bdf10 h1:GFCKgmp0tecUJ0sJuv4pzYCqS9+RGSn52M3FUwPs+uo=
 github.com/planetscale/vtprotobuf v0.6.1-0.20240319094008-0393e58bdf10/go.mod h1:t/avpk3KcrXxUnYOhZhMXJlSEyie6gQbtLq5NM3loB8=
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 h1:Jamvg5psRIccs7FGNTlIRMkT8wgtp5eCXdBlqhYGL6U=
 github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/rivo/uniseg v0.1.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
-github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
+github.com/prometheus/client_golang v1.23.2/go.mod h1:Tb1a6LWHB3/SPIzCoaDXI4I8UHKeFTEQ1YCr+0Gyqmg=
+github.com/prometheus/client_model v0.6.2/go.mod h1:y3m2F6Gdpfy6Ut/GBsUqTWZqCUvMVzSfMLjcu6wAwpE=
+github.com/prometheus/common v0.67.5/go.mod h1:SjE/0MzDEEAyrdr5Gqc6G+sXI67maCxzaT3A2+HqjUw=
+github.com/prometheus/procfs v0.20.1/go.mod h1:o9EMBZGRyvDrSPH1RqdxhojkuXstoe4UlK79eF5TGGo=
 github.com/rivo/uniseg v0.4.7 h1:WUdvkW8uEhrYfLC4ZzdpI2ztxP1I582+49Oc5Mq64VQ=
 github.com/rivo/uniseg v0.4.7/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=
 github.com/rogpeppe/go-internal v1.14.1 h1:UQB4HGPB6osV0SQTLymcB4TgvyWu6ZyliaW0tI/otEQ=
@@ -251,6 +292,10 @@ github.com/rogpeppe/go-internal v1.14.1/go.mod h1:MaRKkUm5W0goXpeCfT7UZI6fk/L7L7
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/sagikazarmark/locafero v0.12.0 h1:/NQhBAkUb4+fH1jivKHWusDYFjMOOKU88eegjfxfHb4=
 github.com/sagikazarmark/locafero v0.12.0/go.mod h1:sZh36u/YSZ918v0Io+U9ogLYQJ9tLLBmM4eneO6WwsI=
+github.com/sahilm/fuzzy v0.1.1/go.mod h1:VFvziUEIMCrT6A6tw2RFIXPXXmzXbOsSHF0DOI8ZK9Y=
+github.com/santhosh-tekuri/jsonschema/v6 v6.0.2 h1:KRzFb2m7YtdldCEkzs6KqmJw4nqEVZGK7IN2kJkjTuQ=
+github.com/santhosh-tekuri/jsonschema/v6 v6.0.2/go.mod h1:JXeL+ps8p7/KNMjDQk3TCwPpBy0wYklyWTfbkIzdIFU=
+github.com/sourcegraph/conc v0.3.1-0.20240121214520-5f936abd7ae8/go.mod h1:3n1Cwaq1E1/1lhQhtRK2ts/ZwZEhjcQeJQ1RuC6Q/8U=
 github.com/spf13/afero v1.15.0 h1:b/YBCLWAJdFWJTN9cLhiXXcD7mzKn9Dm86dNnfyQw1I=
 github.com/spf13/afero v1.15.0/go.mod h1:NC2ByUVxtQs4b3sIUphxK0NioZnmxgyCrfzeuq8lxMg=
 github.com/spf13/cast v1.10.0 h1:h2x0u2shc1QuLHfxi+cTJvs30+ZAHOGRic8uyGTDWxY=
@@ -262,13 +307,14 @@ github.com/spf13/pflag v1.0.10 h1:4EBh2KAYBwaONj6b2Ye1GiHfwjqyROoF4RwYO+vPwFk=
 github.com/spf13/pflag v1.0.10/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 github.com/spf13/viper v1.21.0 h1:x5S+0EU27Lbphp4UKm1C+1oQO+rKx36vfCoaVebLFSU=
 github.com/spf13/viper v1.21.0/go.mod h1:P0lhsswPGWD/1lZJ9ny3fYnVqxiegrlNrEmgLjbTCAY=
+github.com/spiffe/go-spiffe/v2 v2.6.0/go.mod h1:gm2SeUoMZEtpnzPNs2Csc0D/gX33k1xIx7lEzqblHEs=
 github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
 github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
 github.com/subosito/gotenv v1.6.0 h1:9NlTDc1FTs4qu0DDq7AEtTPNw6SVm7uBMsUCUjABIf8=
 github.com/subosito/gotenv v1.6.0/go.mod h1:Dk4QP5c2W3ibzajGcXpNraDfq2IrhjMIvMSWPKKo0FU=
 github.com/tidwall/gjson v1.14.2/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
-github.com/tidwall/gjson v1.18.0 h1:FIDeeyB800efLX89e5a8Y0BNH+LOngJyGrIWxG2FKQY=
-github.com/tidwall/gjson v1.18.0/go.mod h1:/wbyibRr2FHMks5tjHJ5F8dMZh3AcwJEMf5vlfC0lxk=
+github.com/tidwall/gjson v1.19.0 h1:xwxm7n691Uf3u5OFjzngavjGTh55KX5q/9w9xHW88JU=
+github.com/tidwall/gjson v1.19.0/go.mod h1:V37/opeE/JbLUOfH0QTXiNez2l0RUjYUhpT4szFQAfc=
 github.com/tidwall/match v1.1.1/go.mod h1:eRSPERbgtNPcGhD8UCthc6PmLEQXEWd3PRB5JTxsfmM=
 github.com/tidwall/match v1.2.0 h1:0pt8FlkOwjN2fPt4bIl4BoNxb98gGHN2ObFEDkrfZnM=
 github.com/tidwall/match v1.2.0/go.mod h1:eRSPERbgtNPcGhD8UCthc6PmLEQXEWd3PRB5JTxsfmM=
@@ -279,68 +325,87 @@ github.com/tidwall/sjson v1.2.5 h1:kLy8mja+1c9jlljvWTlSazM7cKDRfJuR/bOJhcY5NcY=
 github.com/tidwall/sjson v1.2.5/go.mod h1:Fvgq9kS/6ociJEDnK0Fk1cpYF4FIW6ZF7LAe+6jwd28=
 github.com/traefik/yaegi v0.16.1 h1:f1De3DVJqIDKmnasUF6MwmWv1dSEEat0wcpXhD2On3E=
 github.com/traefik/yaegi v0.16.1/go.mod h1:4eVhbPb3LnD2VigQjhYbEJ69vDRFdT2HQNrXx8eEwUY=
-github.com/wk8/go-ordered-map/v2 v2.1.8 h1:5h/BUHu93oj4gIdvHHHGsScSTMijfx5PeYkE/fJgbpc=
+github.com/ulikunitz/xz v0.5.15/go.mod h1:nbz6k7qbPmH4IRqmfOplQw/tblSgqTqBwxkY0oWt/14=
 github.com/wk8/go-ordered-map/v2 v2.1.8/go.mod h1:5nJHM5DyteebpVlHnWMV0rPz6Zp7+xBAnxjb1X5vnTw=
 github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e h1:JVG44RsyaB9T2KIHavMF/ppJZNG9ZpyihvCd0w101no=
 github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e/go.mod h1:RbqR21r5mrJuqunuUZ/Dhy/avygyECGrLceyNeo4LiM=
 github.com/yosida95/uritemplate/v3 v3.0.2 h1:Ed3Oyj9yrmi9087+NczuL5BwkIc4wvTb5zIM+UJPGz4=
 github.com/yosida95/uritemplate/v3 v3.0.2/go.mod h1:ILOh0sOhIJR3+L/8afwt/kE++YT040gmv5BQTMR2HP4=
-github.com/yuin/goldmark v1.7.17 h1:p36OVWwRb246iHxA/U4p8OPEpOTESm4n+g+8t0EE5uA=
-github.com/yuin/goldmark v1.7.17/go.mod h1:ip/1k0VRfGynBgxOz0yCqHrbZXhcjxyuS66Brc7iBKg=
-github.com/yuin/goldmark-emoji v1.0.6 h1:QWfF2FYaXwL74tfGOW5izeiZepUDroDJfWubQI9HTHs=
-github.com/yuin/goldmark-emoji v1.0.6/go.mod h1:ukxJDKFpdFb5x0a5HqbdlcKtebh086iJpI31LTKmWuA=
+github.com/yuin/goldmark v1.8.2 h1:kEGpgqJXdgbkhcOgBxkC0X0PmoPG1ZyoZ117rDVp4zE=
+github.com/yuin/goldmark v1.8.2/go.mod h1:ip/1k0VRfGynBgxOz0yCqHrbZXhcjxyuS66Brc7iBKg=
+github.com/zeebo/errs v1.4.0/go.mod h1:sgbWHsvVuTPHcqJJGQ1WhI5KbWlHYz+2+2C/LSEtCw4=
+go.opencensus.io v0.24.0/go.mod h1:vNK8G9p7aAivkbmorf4v+7Hgx+Zs0yY+0fOtgBfjQKo=
 go.opentelemetry.io/auto/sdk v1.2.1 h1:jXsnJ4Lmnqd11kwkBV2LgLoFMZKizbCi5fNZ/ipaZ64=
 go.opentelemetry.io/auto/sdk v1.2.1/go.mod h1:KRTj+aOaElaLi+wW1kO/DZRXwkF4C5xPbEe3ZiIhN7Y=
-go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.67.0 h1:yI1/OhfEPy7J9eoa6Sj051C7n5dvpj0QX8g4sRchg04=
-go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.67.0/go.mod h1:NoUCKYWK+3ecatC4HjkRktREheMeEtrXoQxrqYFeHSc=
-go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.67.0 h1:OyrsyzuttWTSur2qN/Lm0m2a8yqyIjUVBZcxFPuXq2o=
-go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.67.0/go.mod h1:C2NGBr+kAB4bk3xtMXfZ94gqFDtg/GkI7e9zqGh5Beg=
-go.opentelemetry.io/otel v1.42.0 h1:lSQGzTgVR3+sgJDAU/7/ZMjN9Z+vUip7leaqBKy4sho=
-go.opentelemetry.io/otel v1.42.0/go.mod h1:lJNsdRMxCUIWuMlVJWzecSMuNjE7dOYyWlqOXWkdqCc=
-go.opentelemetry.io/otel/metric v1.42.0 h1:2jXG+3oZLNXEPfNmnpxKDeZsFI5o4J+nz6xUlaFdF/4=
-go.opentelemetry.io/otel/metric v1.42.0/go.mod h1:RlUN/7vTU7Ao/diDkEpQpnz3/92J9ko05BIwxYa2SSI=
-go.opentelemetry.io/otel/sdk v1.42.0 h1:LyC8+jqk6UJwdrI/8VydAq/hvkFKNHZVIWuslJXYsDo=
-go.opentelemetry.io/otel/sdk v1.42.0/go.mod h1:rGHCAxd9DAph0joO4W6OPwxjNTYWghRWmkHuGbayMts=
-go.opentelemetry.io/otel/sdk/metric v1.42.0 h1:D/1QR46Clz6ajyZ3G8SgNlTJKBdGp84q9RKCAZ3YGuA=
-go.opentelemetry.io/otel/sdk/metric v1.42.0/go.mod h1:Ua6AAlDKdZ7tdvaQKfSmnFTdHx37+J4ba8MwVCYM5hc=
-go.opentelemetry.io/otel/trace v1.42.0 h1:OUCgIPt+mzOnaUTpOQcBiM/PLQ/Op7oq6g4LenLmOYY=
-go.opentelemetry.io/otel/trace v1.42.0/go.mod h1:f3K9S+IFqnumBkKhRJMeaZeNk9epyhnCmQh/EysQCdc=
+go.opentelemetry.io/contrib/detectors/gcp v1.43.0/go.mod h1:RyaZMFY7yi1kAs45S6mbFGz8O8rqB0dTY14uzvG4LCs=
+go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.69.0 h1:2yEATaop1/a1I4psnSLgWVPLWwCzkqWakgJy7xTDVy0=
+go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.69.0/go.mod h1:D7J12YRapIekYyPWgGPlA/23pRmpSEZC5xJC/TTLI9U=
+go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.69.0 h1:8tvICD4vSTOOsNrsI4Ljf6C+6UKvpTEH5XY3JMoyPoo=
+go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.69.0/go.mod h1:z9+yiacE0IHRqM4qFfkbt/JYlmYXgss8GY/jXoNuPJI=
+go.opentelemetry.io/otel v1.44.0 h1:JjwHmHpA4iZ3wBxluu2fbbE7j4kqlE8jXyAyPXH7HqU=
+go.opentelemetry.io/otel v1.44.0/go.mod h1:BMgjTHL9WPRlRjL2oZCBTL4whCGtXch2H4BhOPIAyYc=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.43.0/go.mod h1:Vl1/iaggsuRlrHf/hfPJPvVag77kKyvrLeD10kpMl+A=
+go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.43.0/go.mod h1:AGmbycVGEsRx9mXMZ75CsOyhSP6MFIcj/6dnG+vhVjk=
+go.opentelemetry.io/otel/metric v1.44.0 h1:1w0gILTcHdr3YI+ixLyjemwrVnsMURbTZFrSYCdDdmc=
+go.opentelemetry.io/otel/metric v1.44.0/go.mod h1:8O7hanEPBNgEMmybD3s2VBKcgWOCsA6tzHBPODAiquo=
+go.opentelemetry.io/otel/sdk v1.44.0 h1:nHYwb9lK+fJPU/dnT6s7W7Z8itMWyqrnVfbheVYrZ58=
+go.opentelemetry.io/otel/sdk v1.44.0/go.mod h1:Osuydd3Se74nqjAKxid74N5eC+jfEqfTegHRnq58oK0=
+go.opentelemetry.io/otel/sdk/metric v1.44.0 h1:3LlKgI+VjbVsjNRFZJZAJ30WjXC5VkNRks6si09iEfI=
+go.opentelemetry.io/otel/sdk/metric v1.44.0/go.mod h1:5B5pMARnXxKhltooO4xUuCBorl65a4EpnTalObqOigA=
+go.opentelemetry.io/otel/trace v1.44.0 h1:jxF5CsGYCe74MCRx2X4g7WsY/VBKRqqpNvXlX/6gtIk=
+go.opentelemetry.io/otel/trace v1.44.0/go.mod h1:oLl1jrMQAVo6v3GAggN+1VH9VIz9iUSvW53sW1Q8PIE=
+go.opentelemetry.io/proto/otlp v1.10.0/go.mod h1:/CV4QoCR/S9yaPj8utp3lvQPoqMtxXdzn7ozvvozVqk=
+go.yaml.in/yaml/v2 v2.4.4/go.mod h1:gMZqIpDtDqOfM0uNfy0SkpRhvUryYH0Z6wdMYcacYXQ=
 go.yaml.in/yaml/v3 v3.0.4 h1:tfq32ie2Jv2UxXFdLJdh3jXuOzWiL1fo0bu/FbuKpbc=
 go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
-golang.org/x/crypto v0.49.0 h1:+Ng2ULVvLHnJ/ZFEq4KdcDd/cfjrrjjNSXNzxg0Y4U4=
-golang.org/x/crypto v0.49.0/go.mod h1:ErX4dUh2UM+CFYiXZRTcMpEcN8b/1gxEuv3nODoYtCA=
-golang.org/x/exp v0.0.0-20260312153236-7ab1446f8b90 h1:jiDhWWeC7jfWqR9c/uplMOqJ0sbNlNWv0UkzE0vX1MA=
-golang.org/x/exp v0.0.0-20260312153236-7ab1446f8b90/go.mod h1:xE1HEv6b+1SCZ5/uscMRjUBKtIxworgEcEi+/n9NQDQ=
-golang.org/x/net v0.52.0 h1:He/TN1l0e4mmR3QqHMT2Xab3Aj3L9qjbhRm78/6jrW0=
-golang.org/x/net v0.52.0/go.mod h1:R1MAz7uMZxVMualyPXb+VaqGSa3LIaUqk0eEt3w36Sw=
+go.yaml.in/yaml/v4 v4.0.0-rc.3/go.mod h1:aZqd9kCMsGL7AuUv/m/PvWLdg5sjJsZ4oHDEnfPPfY0=
+golang.org/x/crypto v0.52.0 h1:RMs7fP2rXdep0CftQlK8Uf+kibLm7qkCcradZWYz988=
+golang.org/x/crypto v0.52.0/go.mod h1:1QgfPxDqh0T2M/elOJtp9RvuR95kVjir0e6/BvEmGbc=
+golang.org/x/exp v0.0.0-20260603202125-055de637280b h1:v1uXiEBHo8QA0LiGCo7UgHMzHT4Kdfpl2zmtH5vaP1Q=
+golang.org/x/exp v0.0.0-20260603202125-055de637280b/go.mod h1:d2fgXJLVs4dYDHUk5lwMIfzRzSrWCfGZb0ZqeLa/Vcw=
+golang.org/x/image v0.41.0 h1:8wS72eGJMJaBxK6okTzd4WaXumUlTVlb753MlsSvTCo=
+golang.org/x/image v0.41.0/go.mod h1:uIc348UZMSvS5Z65CVZ7iDPaNobNFEPeJ4kbqTOszmA=
+golang.org/x/mod v0.36.0/go.mod h1:moc6ELqsWcOw5Ef3xVprK5ul/MvtVvkIXLziUOICjUQ=
+golang.org/x/net v0.55.0 h1:bcvxaJn3e1U6InsFWt1JUq1aSjnRxLzT2rtD2KfkDF8=
+golang.org/x/net v0.55.0/go.mod h1:L5U2KuzuOe1lY7Z+aWVIKK6qEeJXnXV9yzGA+WCHJww=
 golang.org/x/oauth2 v0.36.0 h1:peZ/1z27fi9hUOFCAZaHyrpWG5lwe0RJEEEeH0ThlIs=
 golang.org/x/oauth2 v0.36.0/go.mod h1:YDBUJMTkDnJS+A4BP4eZBjCqtokkg1hODuPjwiGPO7Q=
 golang.org/x/sync v0.20.0 h1:e0PTpb7pjO8GAtTs2dQ6jYa5BWYlMuX047Dco/pItO4=
 golang.org/x/sync v0.20.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
-golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.42.0 h1:omrd2nAlyT5ESRdCLYdm3+fMfNFE/+Rf4bDIQImRJeo=
-golang.org/x/sys v0.42.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
-golang.org/x/term v0.41.0 h1:QCgPso/Q3RTJx2Th4bDLqML4W6iJiaXFq2/ftQF13YU=
-golang.org/x/term v0.41.0/go.mod h1:3pfBgksrReYfZ5lvYM0kSO0LIkAl4Yl2bXOkKP7Ec2A=
-golang.org/x/text v0.35.0 h1:JOVx6vVDFokkpaq1AEptVzLTpDe9KGpj5tR4/X+ybL8=
-golang.org/x/text v0.35.0/go.mod h1:khi/HExzZJ2pGnjenulevKNX1W67CUy0AsXcNubPGCA=
+golang.org/x/sys v0.45.0 h1:dO4czNzziLiiXplLQgBCEpCvXQ3dnkn0SdaZSYdQ+FY=
+golang.org/x/sys v0.45.0/go.mod h1:4GL1E5IUh+htKOUEOaiffhrAeqysfVGipDYzABqnCmw=
+golang.org/x/term v0.43.0 h1:S4RLU2sB31O/NCl+zFN9Aru9A/Cq2aqKpTZJ6B+DwT4=
+golang.org/x/term v0.43.0/go.mod h1:lrhlHNdQJHO+1qVYiHfFKVuVioJIheAc3fBSMFYEIsk=
+golang.org/x/text v0.37.0 h1:Cqjiwd9eSg8e0QAkyCaQTNHFIIzWtidPahFWR83rTrc=
+golang.org/x/text v0.37.0/go.mod h1:a5sjxXGs9hsn/AJVwuElvCAo9v8QYLzvavO5z2PiM38=
 golang.org/x/time v0.15.0 h1:bbrp8t3bGUeFOx08pvsMYRTCVSMk89u4tKbNOZbp88U=
 golang.org/x/time v0.15.0/go.mod h1:Y4YMaQmXwGQZoFaVFk4YpCt4FLQMYKZe9oeV/f4MSno=
-gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
-gonum.org/v1/gonum v0.16.0/go.mod h1:fef3am4MQ93R2HHpKnLk4/Tbh/s0+wqD5nfa6Pnwy4E=
-google.golang.org/api v0.272.0 h1:eLUQZGnAS3OHn31URRf9sAmRk3w2JjMx37d2k8AjJmA=
-google.golang.org/api v0.272.0/go.mod h1:wKjowi5LNJc5qarNvDCvNQBn3rVK8nSy6jg2SwRwzIA=
-google.golang.org/genai v1.51.0 h1:IZGuUqgfx40INv3hLFGCbOSGp0qFqm7LVmDghzNIYqg=
-google.golang.org/genai v1.51.0/go.mod h1:A3kkl0nyBjyFlNjgxIwKq70julKbIxpSxqKO5gw/gmk=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20260319201613-d00831a3d3e7 h1:ndE4FoJqsIceKP2oYSnUZqhTdYufCYYkqwtFzfrhI7w=
-google.golang.org/genproto/googleapis/rpc v0.0.0-20260319201613-d00831a3d3e7/go.mod h1:4Hqkh8ycfw05ld/3BWL7rJOSfebL2Q+DVDeRgYgxUU8=
-google.golang.org/grpc v1.79.3 h1:sybAEdRIEtvcD68Gx7dmnwjZKlyfuc61Dyo9pGXXkKE=
-google.golang.org/grpc v1.79.3/go.mod h1:KmT0Kjez+0dde/v2j9vzwoAScgEPx/Bw1CYChhHLrHQ=
+golang.org/x/tools v0.45.0/go.mod h1:LuUGqqaXcXMEFEruIVJVm5mgDD8vww/z/SR1gQ4uE/0=
+golang.org/x/tools/go/expect v0.1.1-deprecated/go.mod h1:eihoPOH+FgIqa3FpoTwguz/bVUSGBlGQU67vpBeOrBY=
+golang.org/x/tools/go/packages/packagestest v0.1.1-deprecated/go.mod h1:RVAQXBGNv1ib0J382/DPCRS/BPnsGebyM1Gj5VSDpG8=
+gonum.org/v1/gonum v0.17.0 h1:VbpOemQlsSMrYmn7T2OUvQ4dqxQXU+ouZFQsZOx50z4=
+gonum.org/v1/gonum v0.17.0/go.mod h1:El3tOrEuMpv2UdMrbNlKEh9vd86bmQ6vqIcDwxEOc1E=
+google.golang.org/api v0.282.0 h1:WmJiSVqUnKqJCpJOx7YADbXaC+9DDsnGSfllFSj7R2I=
+google.golang.org/api v0.282.0/go.mod h1:6Wssta4c5n9qHq5CBhmlai5h/PUa1djdDAIhYEHyvcM=
+google.golang.org/appengine v1.6.8/go.mod h1:1jJ3jBArFh5pcgW8gCtRJnepW8FzD1V44FJffLiz/Ds=
+google.golang.org/genai v1.58.0 h1:MNA3ZkRyr7MnRwZ9RNZ60p4+UMKV3yYRw6pyHq4pp0U=
+google.golang.org/genai v1.58.0/go.mod h1:A3kkl0nyBjyFlNjgxIwKq70julKbIxpSxqKO5gw/gmk=
+google.golang.org/genproto v0.0.0-20260504160031-60b97b32f348 h1:JjVGDZYWkJWZcxveJGzfkXC5myDVWAd4dZdgbzrDUv8=
+google.golang.org/genproto v0.0.0-20260504160031-60b97b32f348/go.mod h1:95PqD4xM+AdOcBGsmgfaofXsiA37uXDtDufVbntT3TU=
+google.golang.org/genproto/googleapis/api v0.0.0-20260504160031-60b97b32f348 h1:U8orV30l6KpDsi9dxU0CoJZGbjS8EEpw+6ba+XwGPQA=
+google.golang.org/genproto/googleapis/api v0.0.0-20260504160031-60b97b32f348/go.mod h1:Yzdzr5OOZFgSsEV2D/Xi9NL3bszpXFAg0hFJiRohcD8=
+google.golang.org/genproto/googleapis/bytestream v0.0.0-20260523011958-0a33c5d7ca68/go.mod h1:6TABGosqSqU2l1+fJ3jdvOYPPVryeKybxYF0cCZkTBE=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20260526163538-3dc84a4a5aaa h1:mZHHdPZl0dbGHCflZgAq/Q468DWVFcU2whhB2KAo8fk=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20260526163538-3dc84a4a5aaa/go.mod h1:4Hqkh8ycfw05ld/3BWL7rJOSfebL2Q+DVDeRgYgxUU8=
+google.golang.org/grpc v1.81.1 h1:VnnIIZ88UzOOKLukQi+ImGz8O1Wdp8nAGGnvOfEIWQQ=
+google.golang.org/grpc v1.81.1/go.mod h1:xGH9GfzOyMTGIOXBJmXt+BX/V0kcdQbdcuwQ/zNw42I=
 google.golang.org/protobuf v1.36.11 h1:fV6ZwhNocDyBLK0dj+fg8ektcVegBBuEolpbTQyBNVE=
 google.golang.org/protobuf v1.36.11/go.mod h1:HTf+CrKn2C3g5S8VImy6tdcUvCska2kB7j23XfzDpco=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
+gopkg.in/dnaeon/go-vcr.v4 v4.0.6-0.20251110073552-01de4eb40290/go.mod h1:sbq5oMEcM4PXngbcNbHhzfCP9OdZodLhrbRYoyg09HY=
+gopkg.in/ini.v1 v1.67.1/go.mod h1:x/cyOwCgZqOkJoDIJ3c1KNHMo10+nLGAhh+kn3Zizss=
 gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

internal/acpserver/agent.go

@@ -7,8 +7,11 @@ package acpserver
 
 import (
 	"context"
+	"encoding/base64"
 	"encoding/json"
 	"fmt"
+	"os"
+	"strings"
 	"sync/atomic"
 
 	"github.com/charmbracelet/log"
@@ -20,7 +23,6 @@ import (
 // Version is injected at build time; fallback to "dev".
 var Version = "dev"
 
-// Agent implements the acp.Agent interface, delegating to Kit for LLM
 // execution, tool calls, and session management.
 type Agent struct {
 	conn     *acp.AgentSideConnection
@@ -59,6 +61,12 @@ func (a *Agent) Authenticate(_ context.Context, _ acp.AuthenticateRequest) (acp.
 	return acp.AuthenticateResponse{}, nil
 }
 
+// Logout handles logout requests. Kit doesn't require auth for local stdio
+// usage, so this is a no-op.
+func (a *Agent) Logout(_ context.Context, _ acp.LogoutRequest) (acp.LogoutResponse, error) {
+	return acp.LogoutResponse{}, nil
+}
+
 // Initialize negotiates capabilities with the ACP client.
 func (a *Agent) Initialize(_ context.Context, params acp.InitializeRequest) (acp.InitializeResponse, error) {
 	log.Debug("acp: initialize", "protocol_version", params.ProtocolVersion)
@@ -111,13 +119,20 @@ func (a *Agent) Prompt(ctx context.Context, params acp.PromptRequest) (acp.Promp
 		)
 	}
 
-	// Extract text from prompt content blocks.
-	promptText := extractPromptText(params.Prompt)
-	if promptText == "" {
+	// Extract text and file attachments from prompt content blocks.
+	promptText, files := extractPromptContent(params.Prompt)
+	if promptText == "" && len(files) == 0 {
 		return acp.PromptResponse{}, acp.NewInvalidParams("empty prompt")
 	}
 
-	log.Debug("acp: prompt", "session", sessionID, "prompt_len", len(promptText))
+	// If we have files but no text prompt, add a default prompt
+	// This is required because the underlying LLM library needs a non-empty prompt
+	// when there are no previous messages in the conversation.
+	if promptText == "" && len(files) > 0 {
+		promptText = "Please analyze the attached file."
+	}
+
+	log.Debug("acp: prompt", "session", sessionID, "prompt_len", len(promptText), "files", len(files))
 
 	// Create a cancellable context for this prompt turn.
 	promptCtx, cancel := context.WithCancel(ctx)
@@ -129,7 +144,13 @@ func (a *Agent) Prompt(ctx context.Context, params acp.PromptRequest) (acp.Promp
 	defer unsub()
 
 	// Run the prompt through Kit's full turn lifecycle.
-	_, err := sess.kit.PromptResult(promptCtx, promptText)
+	// Use PromptResultWithFiles when file attachments are present.
+	var err error
+	if len(files) > 0 {
+		_, err = sess.kit.PromptResultWithFiles(promptCtx, promptText, files)
+	} else {
+		_, err = sess.kit.PromptResult(promptCtx, promptText)
+	}
 	if err != nil {
 		if promptCtx.Err() != nil {
 			return acp.PromptResponse{
@@ -162,6 +183,77 @@ func (a *Agent) SetSessionMode(_ context.Context, _ acp.SetSessionModeRequest) (
 	return acp.SetSessionModeResponse{}, nil
 }
 
+// ListSessions returns an empty session list. Kit doesn't persist sessions
+// across restarts in ACP mode, so this is effectively a no-op.
+func (a *Agent) ListSessions(_ context.Context, _ acp.ListSessionsRequest) (acp.ListSessionsResponse, error) {
+	return acp.ListSessionsResponse{
+		Sessions: []acp.SessionInfo{},
+	}, nil
+}
+
+// CloseSession cancels any ongoing work for the session and frees its resources.
+func (a *Agent) CloseSession(_ context.Context, params acp.CloseSessionRequest) (acp.CloseSessionResponse, error) {
+	sessionID := string(params.SessionId)
+	sess, ok := a.registry.get(sessionID)
+	if !ok {
+		return acp.CloseSessionResponse{}, nil
+	}
+
+	log.Debug("acp: close session", "session", sessionID)
+	sess.cancelPrompt()
+	a.registry.remove(sessionID)
+	return acp.CloseSessionResponse{}, nil
+}
+
+// ResumeSession is not supported — Kit doesn't persist sessions across
+// restarts in ACP mode. Clients should use NewSession instead.
+func (a *Agent) ResumeSession(_ context.Context, _ acp.ResumeSessionRequest) (acp.ResumeSessionResponse, error) {
+	return acp.ResumeSessionResponse{}, fmt.Errorf("resume session not supported")
+}
+
+// SetSessionConfigOption handles session configuration changes. Currently
+// supports the "model" config option to change the active model for a session.
+func (a *Agent) SetSessionConfigOption(ctx context.Context, params acp.SetSessionConfigOptionRequest) (acp.SetSessionConfigOptionResponse, error) {
+	// Extract session ID and config ID from whichever variant is present.
+	var sessionID string
+	var configID string
+	var value string
+
+	switch {
+	case params.ValueId != nil:
+		sessionID = string(params.ValueId.SessionId)
+		configID = string(params.ValueId.ConfigId)
+		value = string(params.ValueId.Value)
+	case params.Boolean != nil:
+		sessionID = string(params.Boolean.SessionId)
+		configID = string(params.Boolean.ConfigId)
+		// Boolean config options are not used for model selection.
+		log.Debug("acp: set_session_config_option (boolean)", "session", sessionID, "config", configID, "value", params.Boolean.Value)
+		return acp.SetSessionConfigOptionResponse{}, nil
+	default:
+		return acp.SetSessionConfigOptionResponse{}, acp.NewInvalidParams("unsupported config option variant")
+	}
+
+	sess, ok := a.registry.get(sessionID)
+	if !ok {
+		return acp.SetSessionConfigOptionResponse{}, acp.NewInvalidParams(fmt.Sprintf("session not found: %s", sessionID))
+	}
+
+	log.Debug("acp: set_session_config_option", "session", sessionID, "config", configID, "value", value)
+
+	// Handle known config options.
+	switch configID {
+	case "model":
+		if err := sess.kit.SetModel(ctx, value); err != nil {
+			return acp.SetSessionConfigOptionResponse{}, fmt.Errorf("set model: %w", err)
+		}
+	default:
+		log.Debug("acp: unknown config option", "config", configID)
+	}
+
+	return acp.SetSessionConfigOptionResponse{}, nil
+}
+
 // ---------------------------------------------------------------------------
 // Event streaming: Kit events → ACP SessionUpdate notifications
 // ---------------------------------------------------------------------------
@@ -231,19 +323,196 @@ func (a *Agent) subscribeEvents(ctx context.Context, k *kit.Kit, sessionID acp.S
 // Helpers
 // ---------------------------------------------------------------------------
 
-// extractPromptText extracts the concatenated text content from ACP content
-// blocks. Non-text blocks are ignored for now.
-func extractPromptText(blocks []acp.ContentBlock) string {
-	var text string
-	for _, block := range blocks {
-		if block.Text != nil {
-			if text != "" {
-				text += "\n"
+// extractPromptContent extracts text and file attachments from ACP content blocks.
+// It converts supported content blocks (image, audio, resource) to Kit's LLMFilePart.
+func extractPromptContent(blocks []acp.ContentBlock) (string, []kit.LLMFilePart) {
+	var textParts []string
+	var files []kit.LLMFilePart
+
+	log.Debug("acp: extracting content", "blocks", len(blocks))
+
+	for i, block := range blocks {
+		switch {
+		// Text content
+		case block.Text != nil:
+			log.Debug("acp: content block", "index", i, "type", "text", "len", len(block.Text.Text))
+			textParts = append(textParts, block.Text.Text)
+
+		// Image data (base64)
+		case block.Image != nil:
+			mimeType := block.Image.MimeType
+			if mimeType == "" {
+				mimeType = "image/png" // Default fallback
 			}
-			text += block.Text.Text
+			log.Debug("acp: content block", "index", i, "type", "image", "mime", mimeType, "data_len", len(block.Image.Data))
+			if data, err := base64.StdEncoding.DecodeString(block.Image.Data); err == nil {
+				files = append(files, kit.LLMFilePart{
+					Filename:  "image.png",
+					Data:      data,
+					MediaType: mimeType,
+				})
+			} else {
+				log.Debug("acp: failed to decode image", "error", err)
+			}
+
+		// Audio data (base64)
+		case block.Audio != nil:
+			mimeType := block.Audio.MimeType
+			if mimeType == "" {
+				mimeType = "audio/wav" // Default fallback
+			}
+			log.Debug("acp: content block", "index", i, "type", "audio", "mime", mimeType)
+			if data, err := base64.StdEncoding.DecodeString(block.Audio.Data); err == nil {
+				files = append(files, kit.LLMFilePart{
+					Filename:  "audio.wav",
+					Data:      data,
+					MediaType: mimeType,
+				})
+			} else {
+				log.Debug("acp: failed to decode audio", "error", err)
+			}
+
+		// Embedded resource (text or binary file content)
+		case block.Resource != nil:
+			log.Debug("acp: content block", "index", i, "type", "resource")
+			res := block.Resource.Resource
+			// Text resource - append as text content with file reference
+			if res.TextResourceContents != nil {
+				uri := res.TextResourceContents.Uri
+				content := res.TextResourceContents.Text
+				mimeType := "text/plain"
+				if res.TextResourceContents.MimeType != nil {
+					mimeType = *res.TextResourceContents.MimeType
+				}
+				log.Debug("acp: text resource", "uri", uri, "mime", mimeType, "len", len(content))
+				// Text files are included as formatted text, NOT as FilePart
+				// FilePart is for binary files (images, audio, PDFs) only
+				textParts = append(textParts, fmt.Sprintf("[File: %s]\n```\n%s\n```", uri, content))
+			}
+			// Binary resource (base64 blob) - these become FilePart
+			if res.BlobResourceContents != nil {
+				uri := res.BlobResourceContents.Uri
+				mimeType := "application/octet-stream"
+				if res.BlobResourceContents.MimeType != nil {
+					mimeType = *res.BlobResourceContents.MimeType
+				}
+				log.Debug("acp: binary resource", "uri", uri, "mime", mimeType, "blob_len", len(res.BlobResourceContents.Blob))
+				if data, err := base64.StdEncoding.DecodeString(res.BlobResourceContents.Blob); err == nil {
+					files = append(files, kit.LLMFilePart{
+						Filename:  extractFilenameFromURI(uri),
+						Data:      data,
+						MediaType: mimeType,
+					})
+				} else {
+					log.Debug("acp: failed to decode binary resource", "error", err)
+				}
+			}
+
+		// Resource link (file reference without embedded content)
+		case block.ResourceLink != nil:
+			uri := block.ResourceLink.Uri
+			name := block.ResourceLink.Name
+			log.Debug("acp: content block", "index", i, "type", "resource_link", "uri", uri, "name", name)
+			// For resource links, we'll try to read the file from disk
+			// This requires the file URI to be accessible (file:// scheme)
+			if content, err := readResourceFromURI(uri); err == nil {
+				// Detect if it's a text file or binary file
+				mimeType := "text/plain"
+				if block.ResourceLink.MimeType != nil {
+					mimeType = *block.ResourceLink.MimeType
+				}
+				log.Debug("acp: resource link loaded", "uri", uri, "mime", mimeType, "size", len(content))
+
+				// Only create FilePart for binary files (images, audio, PDFs, etc.)
+				// Text files are included as formatted text in the message
+				if isTextMimeType(mimeType) || looksLikeText(content) {
+					textParts = append(textParts, fmt.Sprintf("[File: %s]\n```\n%s\n```", uri, string(content)))
+				} else {
+					// Binary file - create FilePart for models that support it
+					files = append(files, kit.LLMFilePart{
+						Filename:  extractFilenameFromURI(uri),
+						Data:      content,
+						MediaType: mimeType,
+					})
+				}
+			} else {
+				// If we can't read it, include as a text reference
+				log.Debug("acp: resource link failed to load", "uri", uri, "error", err)
+				textParts = append(textParts, fmt.Sprintf("[Referenced file: %s]", uri))
+			}
+
+		default:
+			log.Debug("acp: content block", "index", i, "type", "unknown/unhandled")
 		}
 	}
-	return text
+
+	// Debug log the extracted content
+	for i, f := range files {
+		log.Debug("acp: extracted file", "index", i, "filename", f.Filename, "mime", f.MediaType, "size", len(f.Data))
+	}
+
+	return strings.Join(textParts, "\n"), files
+}
+
+// isTextMimeType returns true if the MIME type indicates text content.
+func isTextMimeType(mimeType string) bool {
+	return strings.HasPrefix(mimeType, "text/") ||
+		mimeType == "application/json" ||
+		mimeType == "application/xml" ||
+		mimeType == "application/javascript" ||
+		mimeType == "application/typescript" ||
+		mimeType == "application/x-sh" ||
+		mimeType == "application/x-python" ||
+		mimeType == "application/x-yaml" ||
+		mimeType == "application/x-toml"
+}
+
+// looksLikeText checks if the content appears to be text (not binary).
+// It samples the first 512 bytes and checks for null bytes or high
+// concentration of non-printable characters.
+func looksLikeText(data []byte) bool {
+	if len(data) == 0 {
+		return true
+	}
+	// Check first 512 bytes (or less if file is smaller)
+	sampleSize := min(len(data), 512)
+	sample := data[:sampleSize]
+
+	// Count non-printable characters
+	nonPrintable := 0
+	for _, b := range sample {
+		// Null byte indicates binary
+		if b == 0 {
+			return false
+		}
+		// Count control characters (except common whitespace)
+		if b < 32 && b != '\n' && b != '\r' && b != '\t' {
+			nonPrintable++
+		}
+	}
+
+	// If more than 30% non-printable, consider it binary
+	return float64(nonPrintable)/float64(sampleSize) < 0.3
+}
+
+// extractFilenameFromURI extracts a filename from a file URI or path.
+func extractFilenameFromURI(uri string) string {
+	// Handle file:// URIs
+	uri = strings.TrimPrefix(uri, "file://")
+	// Extract basename
+	if idx := strings.LastIndex(uri, "/"); idx >= 0 {
+		return uri[idx+1:]
+	}
+	return uri
+}
+
+// readResourceFromURI attempts to read file content from a file:// URI.
+func readResourceFromURI(uri string) ([]byte, error) {
+	if !strings.HasPrefix(uri, "file://") {
+		return nil, fmt.Errorf("unsupported URI scheme: %s", uri)
+	}
+	path := uri[7:] // Remove file:// prefix
+	return os.ReadFile(path)
 }
 
 // parseToolArgs attempts to parse a JSON tool args string into a map for

internal/acpserver/session.go

@@ -7,7 +7,9 @@ import (
 	"sync"
 
 	"github.com/charmbracelet/log"
+	"github.com/spf13/viper"
 
+	"github.com/mark3labs/kit/internal/extbridge"
 	"github.com/mark3labs/kit/internal/extensions"
 	kit "github.com/mark3labs/kit/pkg/kit"
 )
@@ -37,10 +39,21 @@ func newSessionRegistry() *sessionRegistry {
 // given working directory. The Kit-generated session ID is used as the ACP
 // session ID so the mapping is 1:1.
 func (r *sessionRegistry) create(ctx context.Context, cwd string) (*acpSession, error) {
+	// Each ACP session gets its own isolated config store (CLI is left nil) so
+	// per-session SetModel / SetThinkingLevel calls cannot race or bleed across
+	// the sessionRegistry. We seed the relevant root-command flag values from
+	// the process-global store (which cobra populated from flags) so launching
+	// `kit acp -m <model> [--thinking-level ...] [--provider-url ...]` is still
+	// honored; .kit.yml and KIT_* env vars are loaded per session by kit.New.
+	streamOn := true
 	kitInstance, err := kit.New(ctx, &kit.Options{
-		SessionDir: cwd,
-		Quiet:      true,
-		Streaming:  true,
+		SessionDir:     cwd,
+		Quiet:          true,
+		Streaming:      &streamOn,
+		Model:          viper.GetString("model"),
+		ThinkingLevel:  viper.GetString("thinking-level"),
+		ProviderURL:    viper.GetString("provider-url"),
+		ProviderAPIKey: viper.GetString("provider-api-key"),
 	})
 	if err != nil {
 		// Provide actionable guidance for provider auth errors, which are
@@ -60,143 +73,71 @@ func (r *sessionRegistry) create(ctx context.Context, cwd string) (*acpSession,
 
 	// Wire extension context with headless implementations so extensions
 	// work in ACP mode. TUI-dependent features (widgets, prompts, editor)
-	// become no-ops or return cancelled; all data/model/tool APIs work
-	// identically to interactive mode.
-	if kitInstance.HasExtensions() {
-		kitInstance.SetExtensionContext(extensions.Context{
-			SessionID:   sessionID,
-			CWD:         cwd,
-			Model:       kitInstance.GetModelString(),
-			Interactive: false,
+	// become no-ops or return cancelled; all data/model/tool APIs come from
+	// extbridge.BaseContext and work identically to interactive mode.
+	if kitInstance.Extensions().HasExtensions() {
+		// Use a background context for subagent spawns: the create() ctx is
+		// request-scoped and may be cancelled before extensions spawn anything.
+		ec := extbridge.BaseContext(context.Background(), kitInstance)
 
-			// Output — route through structured logger.
-			Print:      func(text string) { log.Debug("extension: print", "text", text) },
-			PrintInfo:  func(text string) { log.Info("extension: info", "text", text) },
-			PrintError: func(text string) { log.Error("extension: error", "text", text) },
-			PrintBlock: func(opts extensions.PrintBlockOpts) {
-				log.Info("extension: block", "subtitle", opts.Subtitle, "text", opts.Text)
-			},
+		ec.SessionID = sessionID
+		ec.CWD = cwd
+		ec.Model = kitInstance.GetModelString()
+		ec.Interactive = false
 
-			// Message injection — no-ops for now; ACP clients drive prompts.
-			SendMessage:   func(string) {},
-			CancelAndSend: func(string) {},
-			Exit:          func() {},
+		// Output — route through structured logger.
+		ec.Print = func(text string) { log.Debug("extension: print", "text", text) }
+		ec.PrintInfo = func(text string) { log.Info("extension: info", "text", text) }
+		ec.PrintError = func(text string) { log.Error("extension: error", "text", text) }
+		ec.PrintBlock = func(opts extensions.PrintBlockOpts) {
+			log.Info("extension: block", "subtitle", opts.Subtitle, "text", opts.Text)
+		}
 
-			// TUI widgets/chrome — silent no-ops (no TUI in ACP).
-			SetWidget:       func(extensions.WidgetConfig) {},
-			RemoveWidget:    func(string) {},
-			SetHeader:       func(extensions.HeaderFooterConfig) {},
-			RemoveHeader:    func() {},
-			SetFooter:       func(extensions.HeaderFooterConfig) {},
-			RemoveFooter:    func() {},
-			SetEditor:       func(extensions.EditorConfig) {},
-			ResetEditor:     func() {},
-			SetEditorText:   func(string) {},
-			SetUIVisibility: func(extensions.UIVisibility) {},
-			SetStatus:       func(string, string, int) {},
-			RemoveStatus:    func(string) {},
+		// Message injection — no-ops for now; ACP clients drive prompts.
+		ec.SendMessage = func(string) {}
+		ec.CancelAndSend = func(string) {}
+		ec.Exit = func() {}
 
-			// Interactive prompts — return cancelled (no user to prompt).
-			PromptSelect: func(extensions.PromptSelectConfig) extensions.PromptSelectResult {
-				return extensions.PromptSelectResult{Cancelled: true}
-			},
-			PromptConfirm: func(extensions.PromptConfirmConfig) extensions.PromptConfirmResult {
-				return extensions.PromptConfirmResult{Cancelled: true}
-			},
-			PromptInput: func(extensions.PromptInputConfig) extensions.PromptInputResult {
-				return extensions.PromptInputResult{Cancelled: true}
-			},
-			ShowOverlay: func(extensions.OverlayConfig) extensions.OverlayResult {
-				return extensions.OverlayResult{Cancelled: true, Index: -1}
-			},
-			SuspendTUI: func(callback func()) error { callback(); return nil },
+		// TUI widgets/chrome — silent no-ops (no TUI in ACP).
+		ec.SetWidget = func(extensions.WidgetConfig) {}
+		ec.RemoveWidget = func(string) {}
+		ec.SetHeader = func(extensions.HeaderFooterConfig) {}
+		ec.RemoveHeader = func() {}
+		ec.SetFooter = func(extensions.HeaderFooterConfig) {}
+		ec.RemoveFooter = func() {}
+		ec.SetEditor = func(extensions.EditorConfig) {}
+		ec.ResetEditor = func() {}
+		ec.SetEditorText = func(string) {}
+		ec.SetUIVisibility = func(extensions.UIVisibility) {}
+		ec.SetStatus = func(string, string, int) {}
+		ec.RemoveStatus = func(string) {}
 
-			// Data access — delegate to Kit instance.
-			GetContextStats: func() extensions.ContextStats {
-				s := kitInstance.GetContextStats()
-				return extensions.ContextStats{
-					EstimatedTokens: s.EstimatedTokens,
-					ContextLimit:    s.ContextLimit,
-					UsagePercent:    s.UsagePercent,
-					MessageCount:    s.MessageCount,
-				}
-			},
-			GetMessages:    func() []extensions.SessionMessage { return kitInstance.GetSessionMessages() },
-			GetSessionPath: func() string { return kitInstance.GetSessionFilePath() },
-			AppendEntry: func(entryType, data string) (string, error) {
-				return kitInstance.AppendExtensionEntry(entryType, data)
-			},
-			GetEntries: func(entryType string) []extensions.ExtensionEntry {
-				return kitInstance.GetExtensionEntries(entryType)
-			},
+		// Interactive prompts — return cancelled (no user to prompt).
+		ec.PromptSelect = func(extensions.PromptSelectConfig) extensions.PromptSelectResult {
+			return extensions.PromptSelectResult{Cancelled: true}
+		}
+		ec.PromptConfirm = func(extensions.PromptConfirmConfig) extensions.PromptConfirmResult {
+			return extensions.PromptConfirmResult{Cancelled: true}
+		}
+		ec.PromptInput = func(extensions.PromptInputConfig) extensions.PromptInputResult {
+			return extensions.PromptInputResult{Cancelled: true}
+		}
+		ec.ShowOverlay = func(extensions.OverlayConfig) extensions.OverlayResult {
+			return extensions.OverlayResult{Cancelled: true, Index: -1}
+		}
+		ec.SuspendTUI = func(callback func()) error { callback(); return nil }
 
-			// Options, model, and tool management.
-			GetOption: func(name string) string { return kitInstance.GetExtensionOption(name) },
-			SetOption: func(name, value string) { kitInstance.SetExtensionOption(name, value) },
-			SetModel: func(modelString string) error {
-				previousModel := kitInstance.GetExtensionContext().Model
-				if err := kitInstance.SetModel(context.Background(), modelString); err != nil {
-					return err
-				}
-				kitInstance.UpdateExtensionContextModel(modelString)
-				kitInstance.EmitModelChange(modelString, previousModel, "extension")
-				return nil
-			},
-			GetAvailableModels: func() []extensions.ModelInfoEntry { return kitInstance.GetAvailableModels() },
-			EmitCustomEvent:    func(name, data string) { kitInstance.EmitExtensionCustomEvent(name, data) },
-			GetAllTools:        func() []extensions.ToolInfo { return kitInstance.GetExtensionToolInfos() },
-			SetActiveTools:     func(names []string) { kitInstance.SetExtensionActiveTools(names) },
+		// Render — fall back to logging.
+		ec.RenderMessage = func(name, content string) {
+			renderer := kitInstance.Extensions().GetMessageRenderer(name)
+			if renderer != nil && renderer.Render != nil {
+				content = renderer.Render(content, 80)
+			}
+			log.Info("extension: message", "renderer", name, "content", content)
+		}
 
-			// LLM completions and subagents.
-			Complete: func(req extensions.CompleteRequest) (extensions.CompleteResponse, error) {
-				return kitInstance.ExecuteCompletion(context.Background(), req)
-			},
-			SpawnSubagent: func(config extensions.SubagentConfig) (*extensions.SubagentHandle, *extensions.SubagentResult, error) {
-				sdkCfg := kit.SubagentConfig{
-					Prompt:       config.Prompt,
-					Model:        config.Model,
-					SystemPrompt: config.SystemPrompt,
-					Timeout:      config.Timeout,
-					NoSession:    config.NoSession,
-				}
-				if config.OnEvent != nil {
-					sdkCfg.OnEvent = func(e kit.Event) {
-						se := sdkEventToSubagentEvent(e)
-						if se.Type != "" {
-							config.OnEvent(se)
-						}
-					}
-				}
-				result, err := kitInstance.Subagent(context.Background(), sdkCfg)
-				if result == nil {
-					return nil, &extensions.SubagentResult{Error: err}, err
-				}
-				extResult := &extensions.SubagentResult{
-					Response:  result.Response,
-					Error:     result.Error,
-					SessionID: result.SessionID,
-					Elapsed:   result.Elapsed,
-				}
-				if result.Usage != nil {
-					extResult.Usage = &extensions.SubagentUsage{
-						InputTokens:  result.Usage.InputTokens,
-						OutputTokens: result.Usage.OutputTokens,
-					}
-				}
-				return nil, extResult, err
-			},
-
-			// Render — fall back to logging.
-			RenderMessage: func(name, content string) {
-				renderer := kitInstance.GetExtensionMessageRenderer(name)
-				if renderer != nil && renderer.Render != nil {
-					content = renderer.Render(content, 80)
-				}
-				log.Info("extension: message", "renderer", name, "content", content)
-			},
-			ReloadExtensions: func() error { return kitInstance.ReloadExtensions() },
-		})
-		kitInstance.EmitSessionStart()
+		kitInstance.Extensions().SetContext(ec)
+		kitInstance.Extensions().EmitSessionStart()
 	}
 
 	sess := &acpSession{
@@ -232,6 +173,20 @@ func (r *sessionRegistry) closeAll() {
 	}
 }
 
+// remove closes and removes a single session by ID.
+func (r *sessionRegistry) remove(sessionID string) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	sess, ok := r.sessions[sessionID]
+	if !ok {
+		return
+	}
+	if sess.kit != nil {
+		_ = sess.kit.Close()
+	}
+	delete(r.sessions, sessionID)
+}
+
 // cancelPrompt cancels the current prompt for a session, if any.
 func (s *acpSession) cancelPrompt() {
 	s.cancelMu.Lock()
@@ -255,40 +210,3 @@ func (s *acpSession) clearCancel() {
 	defer s.cancelMu.Unlock()
 	s.cancelFn = nil
 }
-
-// sdkEventToSubagentEvent converts an SDK event to an extension SubagentEvent.
-func sdkEventToSubagentEvent(e kit.Event) extensions.SubagentEvent {
-	switch ev := e.(type) {
-	case kit.MessageUpdateEvent:
-		return extensions.SubagentEvent{Type: "text", Content: ev.Chunk}
-	case kit.ReasoningDeltaEvent:
-		return extensions.SubagentEvent{Type: "reasoning", Content: ev.Delta}
-	case kit.ToolCallEvent:
-		return extensions.SubagentEvent{
-			Type: "tool_call", ToolCallID: ev.ToolCallID,
-			ToolName: ev.ToolName, ToolKind: ev.ToolKind, ToolArgs: ev.ToolArgs,
-		}
-	case kit.ToolExecutionStartEvent:
-		return extensions.SubagentEvent{
-			Type: "tool_execution_start", ToolCallID: ev.ToolCallID,
-			ToolName: ev.ToolName, ToolKind: ev.ToolKind,
-		}
-	case kit.ToolExecutionEndEvent:
-		return extensions.SubagentEvent{
-			Type: "tool_execution_end", ToolCallID: ev.ToolCallID,
-			ToolName: ev.ToolName, ToolKind: ev.ToolKind,
-		}
-	case kit.ToolResultEvent:
-		return extensions.SubagentEvent{
-			Type: "tool_result", ToolCallID: ev.ToolCallID,
-			ToolName: ev.ToolName, ToolKind: ev.ToolKind,
-			ToolResult: ev.Result, IsError: ev.IsError,
-		}
-	case kit.TurnStartEvent:
-		return extensions.SubagentEvent{Type: "turn_start"}
-	case kit.TurnEndEvent:
-		return extensions.SubagentEvent{Type: "turn_end"}
-	default:
-		return extensions.SubagentEvent{}
-	}
-}

internal/agent/agent_mcp_test.go

@@ -0,0 +1,302 @@
+package agent
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+	"time"
+
+	"charm.land/fantasy"
+
+	"github.com/mark3labs/kit/internal/config"
+)
+
+// mockModel is a minimal LanguageModel that satisfies the interface
+// without making real API calls. Used to test tool management wiring.
+type mockModel struct{}
+
+func (m *mockModel) Generate(_ context.Context, _ fantasy.Call) (*fantasy.Response, error) {
+	return &fantasy.Response{}, nil
+}
+func (m *mockModel) Stream(_ context.Context, _ fantasy.Call) (fantasy.StreamResponse, error) {
+	return nil, nil
+}
+func (m *mockModel) GenerateObject(_ context.Context, _ fantasy.ObjectCall) (*fantasy.ObjectResponse, error) {
+	return &fantasy.ObjectResponse{}, nil
+}
+func (m *mockModel) StreamObject(_ context.Context, _ fantasy.ObjectCall) (fantasy.ObjectStreamResponse, error) {
+	return nil, nil
+}
+func (m *mockModel) Provider() string { return "mock" }
+func (m *mockModel) Model() string    { return "mock-model" }
+
+// testdataDir returns the absolute path to the tools testdata directory.
+func testdataDir(t *testing.T) string {
+	t.Helper()
+	_, file, _, ok := runtime.Caller(0)
+	if !ok {
+		t.Fatal("cannot determine test file path")
+	}
+	return filepath.Join(filepath.Dir(file), "..", "tools", "testdata")
+}
+
+// echoServerConfig returns an MCPServerConfig for the test echo MCP server.
+func echoServerConfig(t *testing.T) config.MCPServerConfig {
+	t.Helper()
+	script := filepath.Join(testdataDir(t), "echo_server.py")
+	if _, err := os.Stat(script); err != nil {
+		t.Skipf("echo_server.py not found: %v", err)
+	}
+	return config.MCPServerConfig{
+		Command: []string{"python3", script},
+	}
+}
+
+// mockAuthHandler is a minimal MCPAuthHandler for testing that auth handler
+// propagation works without requiring a real OAuth server.
+type mockAuthHandler struct {
+	redirectURI string
+}
+
+func (h *mockAuthHandler) RedirectURI() string { return h.redirectURI }
+func (h *mockAuthHandler) HandleAuth(_ context.Context, _ string, _ string) (string, error) {
+	return "", nil
+}
+
+// newTestAgent creates a minimal Agent with a mock model and no core tools,
+// suitable for testing MCP server management without an API key.
+func newTestAgent() *Agent {
+	model := &mockModel{}
+	a := &Agent{
+		model:        model,
+		coreTools:    nil,
+		extraTools:   nil,
+		maxSteps:     10,
+		systemPrompt: "test",
+		fantasyAgent: fantasy.NewAgent(model),
+	}
+	return a
+}
+
+func TestAgent_AddMCPServer(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping integration test in short mode")
+	}
+
+	a := newTestAgent()
+	defer func() { _ = a.Close() }()
+
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	cfg := echoServerConfig(t)
+
+	// Initially no MCP tools.
+	if a.GetMCPToolCount() != 0 {
+		t.Fatalf("Expected 0 MCP tools initially, got %d", a.GetMCPToolCount())
+	}
+
+	// Add a server.
+	count, err := a.AddMCPServer(ctx, "echo", cfg)
+	if err != nil {
+		t.Fatalf("AddMCPServer failed: %v", err)
+	}
+	if count != 2 {
+		t.Errorf("Expected 2 tools, got %d", count)
+	}
+
+	// Verify tools are in the agent's tool list.
+	if a.GetMCPToolCount() != 2 {
+		t.Errorf("Expected 2 MCP tools, got %d", a.GetMCPToolCount())
+	}
+
+	allTools := a.GetTools()
+	toolNames := make(map[string]bool)
+	for _, tool := range allTools {
+		toolNames[tool.Info().Name] = true
+	}
+	if !toolNames["echo__echo"] {
+		t.Error("Expected tool 'echo__echo' in agent tools")
+	}
+	if !toolNames["echo__greet"] {
+		t.Error("Expected tool 'echo__greet' in agent tools")
+	}
+
+	// Verify loaded server names.
+	names := a.GetLoadedServerNames()
+	found := false
+	for _, n := range names {
+		if n == "echo" {
+			found = true
+		}
+	}
+	if !found {
+		t.Errorf("Expected 'echo' in loaded server names: %v", names)
+	}
+}
+
+func TestAgent_RemoveMCPServer(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping integration test in short mode")
+	}
+
+	a := newTestAgent()
+	defer func() { _ = a.Close() }()
+
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	cfg := echoServerConfig(t)
+
+	// Add then remove.
+	_, err := a.AddMCPServer(ctx, "echo", cfg)
+	if err != nil {
+		t.Fatalf("AddMCPServer failed: %v", err)
+	}
+
+	err = a.RemoveMCPServer("echo")
+	if err != nil {
+		t.Fatalf("RemoveMCPServer failed: %v", err)
+	}
+
+	// Verify tools removed.
+	if a.GetMCPToolCount() != 0 {
+		t.Errorf("Expected 0 MCP tools after removal, got %d", a.GetMCPToolCount())
+	}
+
+	// Verify agent's tool list has no MCP tools.
+	for _, tool := range a.GetTools() {
+		if strings.Contains(tool.Info().Name, "echo__") {
+			t.Errorf("Found leftover tool after removal: %s", tool.Info().Name)
+		}
+	}
+}
+
+func TestAgent_RemoveMCPServer_NoToolManager(t *testing.T) {
+	a := newTestAgent()
+	defer func() { _ = a.Close() }()
+
+	err := a.RemoveMCPServer("nonexistent")
+	if err == nil {
+		t.Fatal("Expected error when no tool manager exists")
+	}
+	if !strings.Contains(err.Error(), "no MCP servers loaded") {
+		t.Errorf("Expected 'no MCP servers loaded' error, got: %v", err)
+	}
+}
+
+func TestAgent_AddMCPServer_CreatesToolManager(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping integration test in short mode")
+	}
+
+	a := newTestAgent()
+	defer func() { _ = a.Close() }()
+
+	// Initially no tool manager.
+	if a.GetMCPToolManager() != nil {
+		t.Fatal("Expected nil tool manager initially")
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	cfg := echoServerConfig(t)
+	_, err := a.AddMCPServer(ctx, "echo", cfg)
+	if err != nil {
+		t.Fatalf("AddMCPServer failed: %v", err)
+	}
+
+	// Tool manager should now exist.
+	if a.GetMCPToolManager() == nil {
+		t.Fatal("Expected tool manager to be created by AddMCPServer")
+	}
+}
+
+func TestAgent_AddRemoveAdd_MCP(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping integration test in short mode")
+	}
+
+	a := newTestAgent()
+	defer func() { _ = a.Close() }()
+
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	cfg := echoServerConfig(t)
+
+	// Add → Remove → Add cycle.
+	_, err := a.AddMCPServer(ctx, "echo", cfg)
+	if err != nil {
+		t.Fatalf("First add failed: %v", err)
+	}
+
+	err = a.RemoveMCPServer("echo")
+	if err != nil {
+		t.Fatalf("Remove failed: %v", err)
+	}
+
+	count, err := a.AddMCPServer(ctx, "echo", cfg)
+	if err != nil {
+		t.Fatalf("Re-add failed: %v", err)
+	}
+	if count != 2 {
+		t.Errorf("Expected 2 tools on re-add, got %d", count)
+	}
+	if a.GetMCPToolCount() != 2 {
+		t.Errorf("Expected 2 MCP tools after re-add, got %d", a.GetMCPToolCount())
+	}
+}
+
+// TestAgent_AddMCPServer_InheritsAuthHandler verifies that AddMCPServer()
+// propagates the agent's authHandler and tokenStoreFactory to a newly created
+// MCPToolManager (fix for issue #3).
+func TestAgent_AddMCPServer_InheritsAuthHandler(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping integration test in short mode")
+	}
+
+	handler := &mockAuthHandler{redirectURI: "http://localhost:9999/oauth/callback"}
+
+	model := &mockModel{}
+	a := &Agent{
+		model:             model,
+		coreTools:         nil,
+		extraTools:        nil,
+		maxSteps:          10,
+		systemPrompt:      "test",
+		fantasyAgent:      fantasy.NewAgent(model),
+		authHandler:       handler,
+		tokenStoreFactory: nil, // nil is fine; we just test authHandler propagation
+	}
+	defer func() { _ = a.Close() }()
+
+	// Initially no tool manager.
+	if a.GetMCPToolManager() != nil {
+		t.Fatal("Expected nil tool manager initially")
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	cfg := echoServerConfig(t)
+	_, err := a.AddMCPServer(ctx, "echo", cfg)
+	if err != nil {
+		t.Fatalf("AddMCPServer failed: %v", err)
+	}
+
+	// Tool manager should now exist and have the auth handler set.
+	tm := a.GetMCPToolManager()
+	if tm == nil {
+		t.Fatal("Expected tool manager to be created by AddMCPServer")
+	}
+
+	// Verify the auth handler was propagated by checking the field directly.
+	if tm.GetAuthHandler() == nil {
+		t.Fatal("Expected auth handler to be propagated to tool manager")
+	}
+}

internal/agent/agent_parallel_tool_args_test.go

@@ -0,0 +1,109 @@
+package agent
+
+import (
+	"context"
+	"sync"
+	"testing"
+
+	"charm.land/fantasy"
+)
+
+// fakeParallelAgent simulates a provider that emits two parallel tool_use
+// blocks in a single step. It invokes the streaming callbacks in the order:
+//
+//	OnToolCall(A) -> OnToolCall(B) -> OnToolResult(A) -> OnToolResult(B)
+//
+// Before the fix in #33 the agent-layer wrapper recorded a single
+// `currentToolArgs` variable that was clobbered by the second OnToolCall, so
+// both OnToolResult callbacks received B's args instead of their own.
+type fakeParallelAgent struct {
+	calls   []fantasy.ToolCallContent
+	results []fantasy.ToolResultContent
+}
+
+func (f *fakeParallelAgent) Generate(_ context.Context, _ fantasy.AgentCall) (*fantasy.AgentResult, error) {
+	return &fantasy.AgentResult{}, nil
+}
+
+func (f *fakeParallelAgent) Stream(_ context.Context, opts fantasy.AgentStreamCall) (*fantasy.AgentResult, error) {
+	for _, tc := range f.calls {
+		if opts.OnToolCall != nil {
+			if err := opts.OnToolCall(tc); err != nil {
+				return nil, err
+			}
+		}
+	}
+	for _, tr := range f.results {
+		if opts.OnToolResult != nil {
+			if err := opts.OnToolResult(tr); err != nil {
+				return nil, err
+			}
+		}
+	}
+	return &fantasy.AgentResult{}, nil
+}
+
+// TestGenerateWithCallbacks_ParallelToolArgs is the regression test for #33.
+// It drives the streaming-callback wiring inside GenerateWithCallbacks with a
+// fake fantasy.Agent that emits two parallel tool calls before either result.
+// Each OnToolResult must receive the args of its own tool call (matched by
+// ToolCallID), not the args of the last OnToolCall in the step.
+func TestGenerateWithCallbacks_ParallelToolArgs(t *testing.T) {
+	t.Parallel()
+
+	argsA := `{"name":"scheduled_jobs"}`
+	argsB := `{"name":"gmail_trigger"}`
+
+	fake := &fakeParallelAgent{
+		calls: []fantasy.ToolCallContent{
+			{ToolCallID: "kit-A", ToolName: "load_skill", Input: argsA},
+			{ToolCallID: "kit-B", ToolName: "load_skill", Input: argsB},
+		},
+		results: []fantasy.ToolResultContent{
+			{ToolCallID: "kit-A", ToolName: "load_skill", Result: fantasy.ToolResultOutputContentText{Text: "ok-A"}},
+			{ToolCallID: "kit-B", ToolName: "load_skill", Result: fantasy.ToolResultOutputContentText{Text: "ok-B"}},
+		},
+	}
+
+	a := &Agent{
+		fantasyAgent:     fake,
+		streamingEnabled: false, // exercise the "hasCallbacks" branch
+	}
+
+	var mu sync.Mutex
+	resultArgs := map[string]string{}
+	executionArgs := map[string]string{} // captured when running == false
+
+	cb := GenerateCallbacks{
+		OnToolExecution: func(id, _, args string, running bool) {
+			if running {
+				return
+			}
+			mu.Lock()
+			defer mu.Unlock()
+			executionArgs[id] = args
+		},
+		OnToolResult: func(id, _, args, _, _ string, _ bool) {
+			mu.Lock()
+			defer mu.Unlock()
+			resultArgs[id] = args
+		},
+	}
+
+	if _, err := a.GenerateWithCallbacks(context.Background(), nil, cb); err != nil {
+		t.Fatalf("GenerateWithCallbacks returned error: %v", err)
+	}
+
+	if got, want := resultArgs["kit-A"], argsA; got != want {
+		t.Errorf("OnToolResult for kit-A: args = %q, want %q", got, want)
+	}
+	if got, want := resultArgs["kit-B"], argsB; got != want {
+		t.Errorf("OnToolResult for kit-B: args = %q, want %q", got, want)
+	}
+	if got, want := executionArgs["kit-A"], argsA; got != want {
+		t.Errorf("OnToolExecution(finish) for kit-A: args = %q, want %q", got, want)
+	}
+	if got, want := executionArgs["kit-B"], argsB; got != want {
+		t.Errorf("OnToolExecution(finish) for kit-B: args = %q, want %q", got, want)
+	}
+}

internal/agent/cache_control.go

@@ -0,0 +1,84 @@
+package agent
+
+import (
+	"charm.land/fantasy"
+	"charm.land/fantasy/providers/anthropic"
+)
+
+// cacheControlOptions returns provider options for Anthropic cache control.
+// This is used at the message level to avoid type conflicts with provider-level options.
+func cacheControlOptions() fantasy.ProviderOptions {
+	return anthropic.NewProviderCacheControlOptions(&anthropic.ProviderCacheControlOptions{
+		CacheControl: anthropic.CacheControl{
+			Type: "ephemeral",
+		},
+	})
+}
+
+// applyCacheControlToMessages adds cache control to specific messages.
+// Anthropic allows max 4 cache blocks per request.
+// Counts existing cache blocks and only adds new ones up to the limit.
+func applyCacheControlToMessages(messages []fantasy.Message) []fantasy.Message {
+	if len(messages) == 0 {
+		return messages
+	}
+
+	// Make a copy to avoid modifying the original slice
+	result := make([]fantasy.Message, len(messages))
+	copy(result, messages)
+
+	cacheOpts := cacheControlOptions()
+	maxCacheBlocks := 4
+
+	// Helper to check if message already has cache control
+	hasCache := func(msg fantasy.Message) bool {
+		if msg.ProviderOptions == nil {
+			return false
+		}
+		if _, ok := msg.ProviderOptions["anthropic"]; ok {
+			return true
+		}
+		return false
+	}
+
+	// Count existing cache blocks
+	existingCacheCount := 0
+	for _, msg := range result {
+		if hasCache(msg) {
+			existingCacheCount++
+		}
+	}
+
+	// If we're already at or over the limit, don't add more
+	if existingCacheCount >= maxCacheBlocks {
+		return result
+	}
+
+	// How many new cache blocks can we add?
+	remaining := maxCacheBlocks - existingCacheCount
+
+	// First: find and cache the last system message (most important)
+	lastSystemIdx := -1
+	for i, msg := range result {
+		if msg.Role == fantasy.MessageRoleSystem {
+			lastSystemIdx = i
+		}
+	}
+
+	if lastSystemIdx >= 0 && remaining > 0 && !hasCache(result[lastSystemIdx]) {
+		result[lastSystemIdx].ProviderOptions = cacheOpts
+		remaining--
+	}
+
+	// Second: cache the most recent messages (up to remaining limit)
+	// Work backwards from the end to prioritize recent context
+	for i := len(result) - 1; i >= 0 && remaining > 0; i-- {
+		if hasCache(result[i]) {
+			continue
+		}
+		result[i].ProviderOptions = cacheOpts
+		remaining--
+	}
+
+	return result
+}

internal/agent/factory.go

@@ -36,13 +36,28 @@ type AgentCreationOptions struct {
 	SpinnerFunc SpinnerFunc // Function to show spinner (provided by caller)
 	// DebugLogger is an optional logger for debugging MCP communications
 	DebugLogger tools.DebugLogger // Optional debug logger
+	// AuthHandler handles OAuth authorization for remote MCP servers
+	AuthHandler tools.MCPAuthHandler
+	// TokenStoreFactory, if non-nil, creates a custom token store for each
+	// remote MCP server's OAuth tokens. When nil, the default file-based
+	// token store is used.
+	TokenStoreFactory tools.TokenStoreFactory
 	// CoreTools overrides the default core tool set. If empty, core.AllTools()
 	// is used.
 	CoreTools []fantasy.AgentTool
-	// ToolWrapper wraps the combined tool list before Fantasy agent creation.
+	// DisableCoreTools, when true, prevents loading any core tools.
+	// If both DisableCoreTools is true and CoreTools is empty, the agent
+	// will have no tools (useful for simple chat completions).
+	DisableCoreTools bool
+	// ToolWrapper wraps the combined tool list before agent creation.
 	ToolWrapper func([]fantasy.AgentTool) []fantasy.AgentTool
 	// ExtraTools are additional tools to include (e.g. from extensions).
 	ExtraTools []fantasy.AgentTool
+	// OnMCPServerLoaded, if non-nil, is called when each MCP server finishes
+	// loading (successfully or with error). Called from the background goroutine.
+	OnMCPServerLoaded func(serverName string, toolCount int, err error)
+	// MCPTaskConfig configures task-augmented tools/call execution.
+	MCPTaskConfig tools.MCPTaskConfig
 }
 
 // CreateAgent creates an agent with optional spinner for Ollama models.
@@ -50,15 +65,20 @@ type AgentCreationOptions struct {
 // Returns the created agent or an error if creation fails.
 func CreateAgent(ctx context.Context, opts *AgentCreationOptions) (*Agent, error) {
 	agentConfig := &AgentConfig{
-		ModelConfig:      opts.ModelConfig,
-		MCPConfig:        opts.MCPConfig,
-		SystemPrompt:     opts.SystemPrompt,
-		MaxSteps:         opts.MaxSteps,
-		StreamingEnabled: opts.StreamingEnabled,
-		DebugLogger:      opts.DebugLogger,
-		CoreTools:        opts.CoreTools,
-		ToolWrapper:      opts.ToolWrapper,
-		ExtraTools:       opts.ExtraTools,
+		ModelConfig:       opts.ModelConfig,
+		MCPConfig:         opts.MCPConfig,
+		SystemPrompt:      opts.SystemPrompt,
+		MaxSteps:          opts.MaxSteps,
+		StreamingEnabled:  opts.StreamingEnabled,
+		DebugLogger:       opts.DebugLogger,
+		AuthHandler:       opts.AuthHandler,
+		TokenStoreFactory: opts.TokenStoreFactory,
+		CoreTools:         opts.CoreTools,
+		DisableCoreTools:  opts.DisableCoreTools,
+		ToolWrapper:       opts.ToolWrapper,
+		ExtraTools:        opts.ExtraTools,
+		OnMCPServerLoaded: opts.OnMCPServerLoaded,
+		MCPTaskConfig:     opts.MCPTaskConfig,
 	}
 
 	var agent *Agent

internal/agent/mcp_adapter.go

@@ -0,0 +1,88 @@
+package agent
+
+import (
+	"context"
+	"fmt"
+
+	"charm.land/fantasy"
+
+	"github.com/mark3labs/kit/internal/tools"
+)
+
+// mcpExecutor is the subset of *tools.MCPToolManager that the adapter
+// actually uses. Extracted as an interface so the adapter is unit-testable
+// without constructing a full manager + connection pool.
+type mcpExecutor interface {
+	ExecuteTool(ctx context.Context, prefixedName, inputJSON string) (*tools.MCPToolResult, error)
+}
+
+// mcpAgentTool adapts an tools.MCPTool to the fantasy.AgentTool interface.
+// This keeps the fantasy dependency confined to the agent layer — the tools
+// package is a pure MCP client library with no LLM framework dependency.
+type mcpAgentTool struct {
+	tool            tools.MCPTool
+	exec            mcpExecutor
+	providerOptions fantasy.ProviderOptions
+}
+
+// Info returns the fantasy tool info including name, description, and parameter schema.
+func (t *mcpAgentTool) Info() fantasy.ToolInfo {
+	return fantasy.ToolInfo{
+		Name:        t.tool.Name,
+		Description: t.tool.Description,
+		Parameters:  t.tool.Parameters,
+		Required:    t.tool.Required,
+	}
+}
+
+// Run executes the MCP tool by delegating to the MCPToolManager.
+//
+// MCP-side failures (JSON-RPC protocol errors, transport failures, schema
+// validation rejections from the server) are surfaced to the model as soft
+// tool errors rather than escalated to a critical agent error. This matches
+// the contract that native Kit tools follow via kit.ErrorResult(...) and
+// lets the model self-correct (e.g. retry with a fixed argument shape) or
+// give up gracefully rather than aborting the turn mid-run.
+//
+// Context cancellation is the one exception: if the caller cancelled the
+// context the turn was aborted intentionally, so we propagate the ctx error
+// to let the agent loop unwind cleanly.
+func (t *mcpAgentTool) Run(ctx context.Context, call fantasy.ToolCall) (fantasy.ToolResponse, error) {
+	result, err := t.exec.ExecuteTool(ctx, t.tool.Name, call.Input)
+	if err != nil {
+		if ctxErr := ctx.Err(); ctxErr != nil {
+			return fantasy.ToolResponse{}, ctxErr
+		}
+		return fantasy.NewTextErrorResponse(
+			fmt.Sprintf("MCP tool %q failed: %s", t.tool.Name, err.Error()),
+		), nil
+	}
+
+	if result.IsError {
+		return fantasy.NewTextErrorResponse(result.Content), nil
+	}
+	return fantasy.NewTextResponse(result.Content), nil
+}
+
+// ProviderOptions returns provider-specific options for this tool.
+func (t *mcpAgentTool) ProviderOptions() fantasy.ProviderOptions {
+	return t.providerOptions
+}
+
+// SetProviderOptions sets provider-specific options for this tool.
+func (t *mcpAgentTool) SetProviderOptions(opts fantasy.ProviderOptions) {
+	t.providerOptions = opts
+}
+
+// mcpToolsToAgentTools converts a slice of MCPTool to fantasy.AgentTool
+// implementations that route execution through the MCPToolManager.
+func mcpToolsToAgentTools(mcpTools []tools.MCPTool, manager *tools.MCPToolManager) []fantasy.AgentTool {
+	agentTools := make([]fantasy.AgentTool, len(mcpTools))
+	for i, t := range mcpTools {
+		agentTools[i] = &mcpAgentTool{
+			tool: t,
+			exec: manager,
+		}
+	}
+	return agentTools
+}

internal/agent/mcp_adapter_test.go

@@ -0,0 +1,158 @@
+package agent
+
+import (
+	"context"
+	"errors"
+	"strings"
+	"testing"
+	"time"
+
+	"charm.land/fantasy"
+
+	"github.com/mark3labs/kit/internal/tools"
+)
+
+// stubExecutor lets each test script the (result, err) pair returned by
+// ExecuteTool. The adapter holds an mcpExecutor interface, so this is the
+// only seam the tests need.
+type stubExecutor struct {
+	result *tools.MCPToolResult
+	err    error
+	// called records the last invocation for assertion.
+	called bool
+	name   string
+	input  string
+}
+
+func (s *stubExecutor) ExecuteTool(_ context.Context, prefixedName, inputJSON string) (*tools.MCPToolResult, error) {
+	s.called = true
+	s.name = prefixedName
+	s.input = inputJSON
+	return s.result, s.err
+}
+
+func newMCPAgentTool(exec mcpExecutor, name string) *mcpAgentTool {
+	return &mcpAgentTool{
+		tool: tools.MCPTool{Name: name},
+		exec: exec,
+	}
+}
+
+// Manager-side Go errors (JSON-RPC protocol errors, transport failures,
+// schema validation rejections from the MCP server) must be surfaced to
+// the model as soft tool errors so the agent loop can keep going. Aborting
+// the turn would discard all prior tool results — see issue #N.
+func TestMCPAgentTool_RPCErrorBecomesSoftError(t *testing.T) {
+	exec := &stubExecutor{
+		err: errors.New("MCP error -32602: Invalid params: missing field \"task\""),
+	}
+	tool := newMCPAgentTool(exec, "pubmed__search")
+
+	resp, err := tool.Run(context.Background(), fantasy.ToolCall{
+		ID:    "call-1",
+		Name:  "pubmed__search",
+		Input: `{"query":"foo"}`,
+	})
+
+	if err != nil {
+		t.Fatalf("expected nil error (soft), got %v", err)
+	}
+	if !resp.IsError {
+		t.Fatalf("expected IsError=true, got false")
+	}
+	if !strings.Contains(resp.Content, "pubmed__search") {
+		t.Errorf("expected tool name in error content, got %q", resp.Content)
+	}
+	if !strings.Contains(resp.Content, "-32602") {
+		t.Errorf("expected underlying error text in content, got %q", resp.Content)
+	}
+}
+
+// Context cancellation is the one error that must remain critical: it
+// means the caller intentionally aborted, and the agent loop needs to
+// unwind cleanly rather than burning more steps.
+func TestMCPAgentTool_CtxCancelStaysCritical(t *testing.T) {
+	exec := &stubExecutor{
+		// Real managers typically return ctx.Err() (or a wrapper) when the
+		// context is cancelled mid-call.
+		err: context.Canceled,
+	}
+	tool := newMCPAgentTool(exec, "slow__tool")
+
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+
+	resp, err := tool.Run(ctx, fantasy.ToolCall{Name: "slow__tool"})
+
+	if !errors.Is(err, context.Canceled) {
+		t.Fatalf("expected context.Canceled, got %v", err)
+	}
+	if resp.IsError || resp.Content != "" {
+		t.Errorf("expected empty response on critical error, got IsError=%v Content=%q", resp.IsError, resp.Content)
+	}
+}
+
+// Deadline-exceeded behaves the same as cancellation: ctx.Err() is
+// non-nil, so the adapter must propagate the critical error rather than
+// converting the executor's error into a soft response.
+func TestMCPAgentTool_CtxDeadlineStaysCritical(t *testing.T) {
+	exec := &stubExecutor{err: context.DeadlineExceeded}
+	tool := newMCPAgentTool(exec, "slow__tool")
+
+	ctx, cancel := context.WithDeadline(context.Background(), time.Now().Add(-time.Second))
+	defer cancel()
+
+	resp, err := tool.Run(ctx, fantasy.ToolCall{Name: "slow__tool"})
+	if !errors.Is(err, context.DeadlineExceeded) {
+		t.Fatalf("expected context.DeadlineExceeded, got %v", err)
+	}
+	if resp.IsError || resp.Content != "" {
+		t.Errorf("expected empty response on critical error, got IsError=%v Content=%q", resp.IsError, resp.Content)
+	}
+}
+
+// Server-side soft errors (CallToolResult{ isError: true }) must continue
+// to flow through as soft errors — this was the existing behavior and
+// must not regress.
+func TestMCPAgentTool_ServerIsErrorRemainsSoftError(t *testing.T) {
+	exec := &stubExecutor{
+		result: &tools.MCPToolResult{
+			IsError: true,
+			Content: "search service is rate limited; try again in 30s",
+		},
+	}
+	tool := newMCPAgentTool(exec, "pubmed__search")
+
+	resp, err := tool.Run(context.Background(), fantasy.ToolCall{Name: "pubmed__search"})
+	if err != nil {
+		t.Fatalf("expected nil error, got %v", err)
+	}
+	if !resp.IsError {
+		t.Fatalf("expected IsError=true, got false")
+	}
+	if resp.Content != "search service is rate limited; try again in 30s" {
+		t.Errorf("expected pass-through content, got %q", resp.Content)
+	}
+}
+
+// Happy path: ordinary successful tool result is passed through unchanged.
+func TestMCPAgentTool_SuccessIsPassthrough(t *testing.T) {
+	exec := &stubExecutor{
+		result: &tools.MCPToolResult{
+			IsError: false,
+			Content: `{"hits":3}`,
+		},
+	}
+	tool := newMCPAgentTool(exec, "pubmed__search")
+
+	resp, err := tool.Run(context.Background(), fantasy.ToolCall{Name: "pubmed__search"})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if resp.IsError {
+		t.Fatalf("expected IsError=false")
+	}
+	if resp.Content != `{"hits":3}` {
+		t.Errorf("expected pass-through content, got %q", resp.Content)
+	}
+}

internal/agent/steer.go

@@ -0,0 +1,46 @@
+package agent
+
+import (
+	"context"
+
+	"charm.land/fantasy"
+)
+
+// SteerMessage carries a steering prompt and optional file attachments
+// (e.g. clipboard images) through the steer channel.
+type SteerMessage struct {
+	Text  string
+	Files []fantasy.FilePart
+}
+
+// steerChKey is the context key for the steer channel.
+type steerChKey struct{}
+
+// steerConsumedKey is the context key for the steer-consumed callback.
+type steerConsumedKey struct{}
+
+// ContextWithSteerCh returns a new context with the steer channel attached.
+// The agent's PrepareStep function checks this channel between steps and
+// injects any pending steer messages as user messages before the next LLM call.
+func ContextWithSteerCh(ctx context.Context, ch <-chan SteerMessage) context.Context {
+	return context.WithValue(ctx, steerChKey{}, ch)
+}
+
+// ContextWithSteerConsumed returns a new context with a callback that fires
+// when steer messages are consumed by PrepareStep. The count argument is the
+// number of messages injected in this batch.
+func ContextWithSteerConsumed(ctx context.Context, fn func(count int)) context.Context {
+	return context.WithValue(ctx, steerConsumedKey{}, fn)
+}
+
+// steerChFromContext extracts the steer channel from the context, or nil.
+func steerChFromContext(ctx context.Context) <-chan SteerMessage {
+	ch, _ := ctx.Value(steerChKey{}).(<-chan SteerMessage)
+	return ch
+}
+
+// steerConsumedFromContext extracts the steer-consumed callback, or nil.
+func steerConsumedFromContext(ctx context.Context) func(int) {
+	fn, _ := ctx.Value(steerConsumedKey{}).(func(int))
+	return fn
+}

internal/app/app_test.go

@@ -3,17 +3,63 @@ package app
 import (
 	"context"
 	"errors"
+	"strings"
 	"sync"
 	"testing"
 	"time"
 
+	tea "charm.land/bubbletea/v2"
+	"charm.land/fantasy"
 	kit "github.com/mark3labs/kit/pkg/kit"
+
+	"github.com/mark3labs/kit/internal/session"
 )
 
 // --------------------------------------------------------------------------
 // Helpers
 // --------------------------------------------------------------------------
 
+type usageUpdaterStub struct {
+	mu sync.Mutex
+
+	updateCalls   int
+	estimateCalls int
+	contextCalls  int
+
+	lastUpdateInput      int
+	lastUpdateOutput     int
+	lastUpdateCacheRead  int
+	lastUpdateCacheWrite int
+	lastContextTokens    int
+	lastEstimateInput    string
+	lastEstimateOutput   string
+}
+
+func (s *usageUpdaterStub) UpdateUsage(inputTokens, outputTokens, cacheReadTokens, cacheWriteTokens int) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.updateCalls++
+	s.lastUpdateInput = inputTokens
+	s.lastUpdateOutput = outputTokens
+	s.lastUpdateCacheRead = cacheReadTokens
+	s.lastUpdateCacheWrite = cacheWriteTokens
+}
+
+func (s *usageUpdaterStub) EstimateAndUpdateUsage(inputText, outputText string) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.estimateCalls++
+	s.lastEstimateInput = inputText
+	s.lastEstimateOutput = outputText
+}
+
+func (s *usageUpdaterStub) SetContextTokens(tokens int) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.contextCalls++
+	s.lastContextTokens = tokens
+}
+
 // turnResult builds a minimal TurnResult with response text t.
 func turnResult(t string) *kit.TurnResult {
 	return &kit.TurnResult{Response: t}
@@ -489,3 +535,583 @@ func TestQueueLength_reflects(t *testing.T) {
 		t.Fatalf("expected 3, got %d", got)
 	}
 }
+
+// TestRecordStepUsage_updatesTracker verifies that per-step usage updates are
+// recorded immediately for cost tracking. Context tokens are also updated so
+// the status bar reflects context fill after every LLM call in a multi-step
+// turn, not just at the end.
+func TestRecordStepUsage_updatesTracker(t *testing.T) {
+	usage := &usageUpdaterStub{}
+	app := New(Options{UsageTracker: usage}, nil)
+	defer app.Close()
+
+	app.recordStepUsage(kit.StepUsageEvent{
+		InputTokens:      120,
+		OutputTokens:     45,
+		CacheReadTokens:  5,
+		CacheWriteTokens: 2,
+	}, nil, nil)
+
+	usage.mu.Lock()
+	defer usage.mu.Unlock()
+
+	if usage.updateCalls != 1 {
+		t.Fatalf("expected 1 update call, got %d", usage.updateCalls)
+	}
+	if usage.lastUpdateInput != 120 || usage.lastUpdateOutput != 45 || usage.lastUpdateCacheRead != 5 || usage.lastUpdateCacheWrite != 2 {
+		t.Fatalf("unexpected usage update payload: in=%d out=%d cache_read=%d cache_write=%d",
+			usage.lastUpdateInput, usage.lastUpdateOutput, usage.lastUpdateCacheRead, usage.lastUpdateCacheWrite)
+	}
+	// Context tokens should now be updated per-step (Input + CacheRead + CacheWrite + Output).
+	if usage.contextCalls != 1 {
+		t.Fatalf("expected 1 context token update from recordStepUsage, got %d", usage.contextCalls)
+	}
+	expectedContext := 120 + 45 + 5 + 2
+	if usage.lastContextTokens != expectedContext {
+		t.Fatalf("expected context tokens %d, got %d", expectedContext, usage.lastContextTokens)
+	}
+}
+
+// TestUpdateUsageFromTurnResult_skipsTotalsWhenStepUsageSeen ensures we avoid
+// double-counting totals once StepUsageEvent-based updates were already applied.
+func TestUpdateUsageFromTurnResult_skipsTotalsWhenStepUsageSeen(t *testing.T) {
+	usage := &usageUpdaterStub{}
+	app := New(Options{UsageTracker: usage}, nil)
+	defer app.Close()
+
+	app.updateUsageFromTurnResult(&kit.TurnResult{
+		Response: "ok",
+		TotalUsage: &kit.LLMUsage{
+			InputTokens:         999,
+			OutputTokens:        111,
+			CacheReadTokens:     7,
+			CacheCreationTokens: 3,
+		},
+		FinalUsage: &kit.LLMUsage{InputTokens: 456},
+	}, "prompt", true)
+
+	usage.mu.Lock()
+	defer usage.mu.Unlock()
+
+	if usage.updateCalls != 0 {
+		t.Fatalf("expected no total usage update when sawStepUsage=true, got %d", usage.updateCalls)
+	}
+	if usage.estimateCalls != 0 {
+		t.Fatalf("expected no estimate update when sawStepUsage=true, got %d", usage.estimateCalls)
+	}
+	// Context tokens should be InputTokens only (456)
+	if usage.contextCalls != 1 || usage.lastContextTokens != 456 {
+		t.Fatalf("expected final context tokens=456 (InputTokens only), got calls=%d tokens=%d", usage.contextCalls, usage.lastContextTokens)
+	}
+}
+
+// TestUpdateUsageFromTurnResult_recordsWhenInputTokensZero verifies that usage
+// is recorded when InputTokens=0 but OutputTokens>0 (OpenAI-compatible cache behavior).
+func TestUpdateUsageFromTurnResult_recordsWhenInputTokensZero(t *testing.T) {
+	usage := &usageUpdaterStub{}
+	app := New(Options{UsageTracker: usage}, nil)
+	defer app.Close()
+
+	// Simulate OpenAI-compatible behavior: all prompt tokens cached, InputTokens=0
+	app.updateUsageFromTurnResult(&kit.TurnResult{
+		Response: "ok",
+		TotalUsage: &kit.LLMUsage{
+			InputTokens:         0,   // All cached - subtracted from prompt
+			OutputTokens:        150, // Actual generated tokens
+			CacheReadTokens:     500, // Cache hit
+			CacheCreationTokens: 0,
+		},
+		FinalUsage: &kit.LLMUsage{InputTokens: 0, OutputTokens: 150},
+	}, "prompt", false)
+
+	usage.mu.Lock()
+	defer usage.mu.Unlock()
+
+	if usage.updateCalls != 1 {
+		t.Fatalf("expected 1 update call when InputTokens=0 but OutputTokens>0, got %d", usage.updateCalls)
+	}
+	if usage.lastUpdateInput != 0 || usage.lastUpdateOutput != 150 {
+		t.Fatalf("expected input=0 output=150, got input=%d output=%d",
+			usage.lastUpdateInput, usage.lastUpdateOutput)
+	}
+	if usage.lastUpdateCacheRead != 500 {
+		t.Fatalf("expected cache_read=500, got %d", usage.lastUpdateCacheRead)
+	}
+}
+
+// TestUpdateUsageFromTurnResult_contextTokensUsesAllCategories verifies that
+// context window fill uses all token categories from the final API call:
+// InputTokens + CacheReadTokens + CacheCreationTokens + OutputTokens.
+// With Anthropic prompt caching, InputTokens can be near-zero while
+// CacheReadTokens holds the bulk of the context.
+func TestUpdateUsageFromTurnResult_contextTokensUsesAllCategories(t *testing.T) {
+	usage := &usageUpdaterStub{}
+	app := New(Options{UsageTracker: usage}, nil)
+	defer app.Close()
+
+	app.updateUsageFromTurnResult(&kit.TurnResult{
+		Response: "ok",
+		TotalUsage: &kit.LLMUsage{
+			InputTokens:         3,
+			OutputTokens:        5,
+			CacheReadTokens:     0,
+			CacheCreationTokens: 4317,
+		},
+		FinalUsage: &kit.LLMUsage{
+			InputTokens:         3,    // Non-cached input (small with caching)
+			OutputTokens:        5,    // Assistant output
+			CacheReadTokens:     0,    // No cache reads on first call
+			CacheCreationTokens: 4317, // System prompt + tools written to cache
+		},
+	}, "prompt", false)
+
+	usage.mu.Lock()
+	defer usage.mu.Unlock()
+
+	// Context tokens should be Input + CacheRead + CacheCreate + Output = 4325
+	expected := 3 + 0 + 4317 + 5
+	if usage.contextCalls != 1 || usage.lastContextTokens != expected {
+		t.Fatalf("expected context tokens=%d (all categories), got calls=%d tokens=%d",
+			expected, usage.contextCalls, usage.lastContextTokens)
+	}
+}
+
+// TestHandleTurnEnd_LengthEmitsWarning verifies that when the SDK reports a
+// FinishReasonLength (max_output_tokens hit), the app surfaces a user-visible
+// ExtensionPrintEvent with Level="info" so the TUI can render a banner
+// instead of silently showing a truncated reply.
+func TestHandleTurnEnd_LengthEmitsWarning(t *testing.T) {
+	app := New(Options{}, nil)
+	defer app.Close()
+
+	var mu sync.Mutex
+	var received []tea.Msg
+	sendFn := func(m tea.Msg) {
+		mu.Lock()
+		defer mu.Unlock()
+		received = append(received, m)
+	}
+
+	app.handleTurnEnd(kit.TurnEndEvent{StopReason: kit.FinishReasonLength}, sendFn)
+
+	mu.Lock()
+	defer mu.Unlock()
+	if len(received) != 1 {
+		t.Fatalf("expected 1 event on length stop, got %d", len(received))
+	}
+	ev, ok := received[0].(ExtensionPrintEvent)
+	if !ok {
+		t.Fatalf("expected ExtensionPrintEvent, got %T", received[0])
+	}
+	if ev.Level != "info" {
+		t.Errorf("expected Level=info, got %q", ev.Level)
+	}
+	if ev.Text == "" {
+		t.Error("expected non-empty warning text")
+	}
+	if !strings.Contains(ev.Text, "max_output_tokens") {
+		t.Errorf("warning text should mention max_output_tokens, got: %s", ev.Text)
+	}
+}
+
+// TestHandleTurnEnd_NonLengthIgnored verifies that ordinary stop reasons
+// (stop, tool-calls, error, unknown, "") do not produce a warning banner.
+func TestHandleTurnEnd_NonLengthIgnored(t *testing.T) {
+	app := New(Options{}, nil)
+	defer app.Close()
+
+	reasons := []string{
+		kit.FinishReasonStop,
+		kit.FinishReasonToolCalls,
+		kit.FinishReasonError,
+		kit.FinishReasonContentFilter,
+		kit.FinishReasonOther,
+		kit.FinishReasonUnknown,
+		"",
+	}
+	for _, r := range reasons {
+		var called bool
+		app.handleTurnEnd(kit.TurnEndEvent{StopReason: r}, func(m tea.Msg) {
+			called = true
+		})
+		if called {
+			t.Errorf("stop reason %q unexpectedly emitted a warning", r)
+		}
+	}
+}
+
+// TestHandleTurnEnd_NilSendFn guards against panics when no TUI listener is
+// attached (e.g. early init or headless teardown).
+func TestHandleTurnEnd_NilSendFn(t *testing.T) {
+	app := New(Options{}, nil)
+	defer app.Close()
+
+	// Should not panic with a nil sendFn.
+	app.handleTurnEnd(kit.TurnEndEvent{StopReason: kit.FinishReasonLength}, nil)
+}
+
+// TestFormatMaxTokensTruncatedMessage_NoKit verifies the fallback message
+// when Options.Kit is nil (test/stub path).
+func TestFormatMaxTokensTruncatedMessage_NoKit(t *testing.T) {
+	app := New(Options{}, nil)
+	defer app.Close()
+
+	msg := app.formatMaxTokensTruncatedMessage()
+	if msg == "" {
+		t.Fatal("expected non-empty fallback message")
+	}
+	for _, needle := range []string{"max_output_tokens", "--max-tokens", "KIT_MAX_TOKENS", "modelSettings"} {
+		if !strings.Contains(msg, needle) {
+			t.Errorf("fallback message missing %q:\n%s", needle, msg)
+		}
+	}
+}
+
+// --------------------------------------------------------------------------
+// releaseBusyAfterCompact (issue #27)
+// --------------------------------------------------------------------------
+
+// TestReleaseBusyAfterCompact_flushesQueuedMessages is a regression test for
+// issue #27: messages queued via Run() while /compact is running used to sit
+// in a.queue indefinitely until the user typed another prompt. After the fix
+// the deferred releaseBusyAfterCompact tail picks up any pending items and
+// dispatches drainQueue automatically.
+//
+// We simulate the compaction completion path directly (bypassing the SDK)
+// by toggling busy=true, populating the queue exactly as Run() would have
+// during compaction, and then invoking releaseBusyAfterCompact.
+func TestReleaseBusyAfterCompact_flushesQueuedMessages(t *testing.T) {
+	stub := newStubWithFuncs(
+		func(ctx context.Context) (*kit.TurnResult, error) {
+			return turnResult("compacted then drained"), nil
+		},
+	)
+	app := newTestApp(stub)
+	defer app.Close()
+
+	// Simulate the state at the start of the compaction tail: busy is set
+	// and a couple of prompts have piled up in the queue while we were
+	// summarising. (Run() would have appended them and returned a queue
+	// length > 0 to the caller.)
+	app.mu.Lock()
+	app.busy = true
+	app.queue = append(app.queue,
+		queueItem{Prompt: "queued during compact #1"},
+		queueItem{Prompt: "queued during compact #2"},
+	)
+	app.mu.Unlock()
+
+	// Invoke the deferred tail directly. It should kick off drainQueue.
+	app.releaseBusyAfterCompact()
+
+	// drainQueue runs in a goroutine. Wait for the app to come back to idle.
+	ok := waitForCondition(2*time.Second, func() bool {
+		app.mu.Lock()
+		defer app.mu.Unlock()
+		return !app.busy
+	})
+	if !ok {
+		t.Fatal("app did not become idle after releaseBusyAfterCompact: queue not drained")
+	}
+
+	// Wait for any in-flight goroutine to finish before reading state.
+	app.wg.Wait()
+
+	if got := app.QueueLength(); got != 0 {
+		t.Fatalf("expected empty queue after drain, got %d", got)
+	}
+	if n := stub.callCount(); n == 0 {
+		t.Fatalf("expected stub PromptFunc to fire at least once after compact, got %d calls", n)
+	}
+}
+
+// TestReleaseBusyAfterCompact_idleWhenQueueEmpty verifies that with no
+// pending messages the helper just clears busy and does NOT spawn a
+// drainQueue goroutine (no spurious agent turn).
+func TestReleaseBusyAfterCompact_idleWhenQueueEmpty(t *testing.T) {
+	stub := newStub()
+	app := newTestApp(stub)
+	defer app.Close()
+
+	app.mu.Lock()
+	app.busy = true
+	app.mu.Unlock()
+
+	app.releaseBusyAfterCompact()
+
+	app.mu.Lock()
+	busy := app.busy
+	app.mu.Unlock()
+	if busy {
+		t.Fatal("expected busy=false after releaseBusyAfterCompact with empty queue")
+	}
+
+	// Give any rogue goroutine a moment to (incorrectly) call PromptFunc.
+	time.Sleep(50 * time.Millisecond)
+	if n := stub.callCount(); n != 0 {
+		t.Fatalf("expected 0 PromptFunc calls when queue empty, got %d", n)
+	}
+}
+
+// TestReleaseBusyAfterCompact_splicesSteerAheadOfQueue exercises the SDK
+// steer-drain branch of releaseBusyAfterCompact (issue #27 follow-up).
+//
+// Production wires a.opts.Kit.DrainSteer() to pull messages that arrived via
+// Steer/SteerWithFiles during compaction, but Options.Kit is *kit.Kit (a
+// concrete struct) so unit tests cannot stand up a real instance without a
+// full LLM backend. The test uses the unexported steerDrainFn seam to inject
+// fake steer items, then asserts that:
+//
+//   - Steer items are dispatched ahead of any prompts that piled up in
+//     a.queue (steer retains "act now" priority over ordinary queued
+//     prompts), and
+//   - the helper still hands off to drainQueue so the steer item actually
+//     fires (the previous behaviour left them stranded — see #27).
+func TestReleaseBusyAfterCompact_splicesSteerAheadOfQueue(t *testing.T) {
+	var pmu sync.Mutex
+	var firstPrompt string
+	stub := newStubWithFuncs(
+		func(ctx context.Context) (*kit.TurnResult, error) {
+			return turnResult("steer dispatched"), nil
+		},
+	)
+	// Wrap PromptFunc so we can capture the prompt text the stub receives
+	// (newStubWithFuncs's fns ignore prompt; we need it to verify ordering).
+	capturingPrompt := func(ctx context.Context, prompt string) (*kit.TurnResult, error) {
+		pmu.Lock()
+		if firstPrompt == "" {
+			firstPrompt = prompt
+		}
+		pmu.Unlock()
+		return stub.fn(ctx, prompt)
+	}
+	app := New(Options{PromptFunc: capturingPrompt}, nil)
+	defer app.Close()
+
+	// Inject fake steer items via the test seam. In production the same
+	// items would have been delivered through Kit.InjectSteerWithFiles
+	// during /compact and pulled by DrainSteer here.
+	app.steerDrainFn = func() []queueItem {
+		return []queueItem{
+			{Prompt: "steer-1"},
+			{Prompt: "steer-2"},
+		}
+	}
+
+	// Simulate the state at the end of compaction: busy is set and a couple
+	// of regular Run() prompts have piled up after the steer messages.
+	app.mu.Lock()
+	app.busy = true
+	app.queue = append(app.queue,
+		queueItem{Prompt: "queued-1"},
+		queueItem{Prompt: "queued-2"},
+	)
+	app.mu.Unlock()
+
+	app.releaseBusyAfterCompact()
+
+	// Wait for the dispatched batch to complete.
+	ok := waitForCondition(2*time.Second, func() bool {
+		app.mu.Lock()
+		defer app.mu.Unlock()
+		return !app.busy
+	})
+	if !ok {
+		t.Fatal("app did not become idle after steer-spliced releaseBusyAfterCompact")
+	}
+	app.wg.Wait()
+
+	// drainQueue picks up `first` directly and batches the rest. With
+	// PromptFunc set, executeBatch invokes us with items[0] only — that
+	// item must be the first steer message, proving steer items were
+	// spliced ahead of the previously queued prompts.
+	pmu.Lock()
+	got := firstPrompt
+	pmu.Unlock()
+	if got != "steer-1" {
+		t.Fatalf("expected first dispatched prompt to be steer item %q (steer items must come before queued prompts), got %q",
+			"steer-1", got)
+	}
+
+	// Queue should be fully drained and PromptFunc must have actually fired.
+	if n := app.QueueLength(); n != 0 {
+		t.Fatalf("expected empty queue after drain, got %d entries", n)
+	}
+	if n := stub.callCount(); n == 0 {
+		t.Fatal("expected stub PromptFunc to fire at least once after splice")
+	}
+}
+
+// TestReleaseBusyAfterCompact_dropsQueueWhenClosed verifies that if the app
+// was closed during compaction the helper discards any pending items rather
+// than spawning drainQueue against a torn-down App.
+func TestReleaseBusyAfterCompact_dropsQueueWhenClosed(t *testing.T) {
+	stub := newStub()
+	app := newTestApp(stub)
+
+	app.mu.Lock()
+	app.busy = true
+	app.queue = append(app.queue, queueItem{Prompt: "would have run"})
+	app.closed = true
+	app.mu.Unlock()
+
+	app.releaseBusyAfterCompact()
+
+	app.mu.Lock()
+	busy := app.busy
+	qLen := len(app.queue)
+	app.mu.Unlock()
+	if busy {
+		t.Fatal("expected busy=false even when closed")
+	}
+	if qLen != 0 {
+		t.Fatalf("expected queue cleared on closed app, got %d entries", qLen)
+	}
+	time.Sleep(20 * time.Millisecond)
+	if n := stub.callCount(); n != 0 {
+		t.Fatalf("expected 0 PromptFunc calls on closed app, got %d", n)
+	}
+}
+
+// --------------------------------------------------------------------------
+// PopLastUserMessage (/retry building block)
+// --------------------------------------------------------------------------
+
+// TestPopLastUserMessage_NoTreeSession verifies that PopLastUserMessage
+// returns an error when no tree session is active.
+func TestPopLastUserMessage_NoTreeSession(t *testing.T) {
+	app := newTestApp(newStub())
+	defer app.Close()
+
+	prompt, files, err := app.PopLastUserMessage()
+	if err == nil {
+		t.Fatal("expected error when no tree session is active")
+	}
+	if prompt != "" || files != nil {
+		t.Fatalf("expected zero values on error, got prompt=%q files=%v", prompt, files)
+	}
+}
+
+// TestPopLastUserMessage_WhileBusy verifies that PopLastUserMessage
+// refuses to truncate while the agent is busy (would race with executeBatch).
+func TestPopLastUserMessage_WhileBusy(t *testing.T) {
+	app := newTestApp(newStub())
+	defer app.Close()
+
+	app.mu.Lock()
+	app.busy = true
+	app.mu.Unlock()
+
+	_, _, err := app.PopLastUserMessage()
+	if err == nil {
+		t.Fatal("expected error when agent is busy")
+	}
+	if !strings.Contains(err.Error(), "working") {
+		t.Fatalf("expected error mentioning busy/working, got %q", err.Error())
+	}
+}
+
+// TestPopLastUserMessage_WhenClosed verifies that PopLastUserMessage
+// returns an error after Close().
+func TestPopLastUserMessage_WhenClosed(t *testing.T) {
+	app := newTestApp(newStub())
+	app.Close()
+
+	_, _, err := app.PopLastUserMessage()
+	if err == nil {
+		t.Fatal("expected error on closed app")
+	}
+}
+
+// TestPopLastUserMessage_TruncatesAndReturnsPrompt verifies the happy path:
+// a real tree session with user→assistant→user→assistant entries is
+// truncated back to before the most recent user message, and that user's
+// text is returned.
+func TestPopLastUserMessage_TruncatesAndReturnsPrompt(t *testing.T) {
+	dir := t.TempDir()
+	ts, err := session.CreateTreeSession(dir)
+	if err != nil {
+		t.Fatalf("create tree session: %v", err)
+	}
+	defer func() { _ = ts.Close() }()
+
+	// Build history: user "first" → assistant "ack 1" → user "second" → assistant "ack 2".
+	if _, err := ts.AppendLLMMessage(fantasy.NewUserMessage("first")); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := ts.AppendLLMMessage(fantasy.Message{
+		Role:    fantasy.MessageRoleAssistant,
+		Content: []fantasy.MessagePart{fantasy.TextPart{Text: "ack 1"}},
+	}); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := ts.AppendLLMMessage(fantasy.NewUserMessage("second")); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := ts.AppendLLMMessage(fantasy.Message{
+		Role:    fantasy.MessageRoleAssistant,
+		Content: []fantasy.MessagePart{fantasy.TextPart{Text: "ack 2"}},
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	app := New(Options{TreeSession: ts, PromptFunc: newStub().fn}, nil)
+	defer app.Close()
+
+	prompt, files, err := app.PopLastUserMessage()
+	if err != nil {
+		t.Fatalf("PopLastUserMessage: %v", err)
+	}
+	if prompt != "second" {
+		t.Fatalf("expected prompt=%q, got %q", "second", prompt)
+	}
+	if files != nil {
+		t.Fatalf("expected no files, got %v", files)
+	}
+
+	// After truncation the branch should only contain the first user
+	// message and its assistant response (the "second" turn is orphaned).
+	msgs := ts.GetLLMMessages()
+	if len(msgs) != 2 {
+		t.Fatalf("expected 2 messages on truncated branch, got %d", len(msgs))
+	}
+	if got := messageText(msgs[0]); got != "first" {
+		t.Fatalf("expected first message %q, got %q", "first", got)
+	}
+	if got := messageText(msgs[1]); got != "ack 1" {
+		t.Fatalf("expected second message %q, got %q", "ack 1", got)
+	}
+}
+
+// messageText extracts concatenated TextPart content from a fantasy.Message.
+func messageText(m fantasy.Message) string {
+	var out strings.Builder
+	for _, p := range m.Content {
+		if tp, ok := p.(fantasy.TextPart); ok {
+			out.WriteString(tp.Text)
+		}
+	}
+	return out.String()
+}
+
+// TestPopLastUserMessage_NoUserOnBranch verifies that an empty tree (no
+// user messages at all) returns a friendly error rather than panicking.
+func TestPopLastUserMessage_NoUserOnBranch(t *testing.T) {
+	dir := t.TempDir()
+	ts, err := session.CreateTreeSession(dir)
+	if err != nil {
+		t.Fatalf("create tree session: %v", err)
+	}
+	defer func() { _ = ts.Close() }()
+
+	app := New(Options{TreeSession: ts, PromptFunc: newStub().fn}, nil)
+	defer app.Close()
+
+	_, _, err = app.PopLastUserMessage()
+	if err == nil {
+		t.Fatal("expected error when no user message exists on branch")
+	}
+	if !strings.Contains(err.Error(), "no user message") {
+		t.Fatalf("expected error mentioning missing user message, got %q", err.Error())
+	}
+}

internal/app/events.go

@@ -1,6 +1,6 @@
 package app
 
-import "charm.land/fantasy"
+import kit "github.com/mark3labs/kit/pkg/kit"
 
 // StreamChunkEvent is sent by the app layer when a streaming text delta arrives
 // from the LLM. Each chunk contains an incremental portion of the response.
@@ -16,6 +16,11 @@ type ReasoningChunkEvent struct {
 	Delta string
 }
 
+// ReasoningCompleteEvent is sent when reasoning/thinking is finished, after
+// the last reasoning token has been processed. The TUI uses this to freeze
+// the reasoning duration counter.
+type ReasoningCompleteEvent struct{}
+
 // ToolCallStartedEvent is sent when a tool call has been parsed and is about to execute.
 // It carries the tool name and its arguments for display purposes.
 type ToolCallStartedEvent struct {
@@ -27,6 +32,36 @@ type ToolCallStartedEvent struct {
 	ToolArgs string
 }
 
+// ToolCallInputStartEvent is sent when the LLM begins generating tool call
+// arguments. The tool name is known but the full argument JSON is still being
+// streamed. UIs can use this to show a "running" indicator immediately instead
+// of waiting for the full argument JSON to finish streaming.
+type ToolCallInputStartEvent struct {
+	// ToolCallID is the stable identifier for correlating tool lifecycle events.
+	ToolCallID string
+	// ToolName is the name of the tool being called.
+	ToolName string
+	// ToolKind classifies the tool: "execute", "edit", "read", "search", "agent".
+	ToolKind string
+}
+
+// ToolCallInputDeltaEvent is sent for each streamed fragment of tool call
+// arguments as they arrive from the LLM. Useful for live-previewing content
+// or showing a progress indicator with byte count.
+type ToolCallInputDeltaEvent struct {
+	// ToolCallID is the stable identifier for correlating tool lifecycle events.
+	ToolCallID string
+	// Delta is a JSON fragment of tool call arguments.
+	Delta string
+}
+
+// ToolCallInputEndEvent is sent when tool argument streaming is complete,
+// before the tool call is parsed and execution begins.
+type ToolCallInputEndEvent struct {
+	// ToolCallID is the stable identifier for correlating tool lifecycle events.
+	ToolCallID string
+}
+
 // ToolExecutionEvent is sent when a tool starts or finishes executing.
 // The IsStarting flag distinguishes between the start and end of execution.
 type ToolExecutionEvent struct {
@@ -74,6 +109,24 @@ type ToolCallContentEvent struct {
 	Content string
 }
 
+// PasswordPromptEvent is sent when a sudo command needs a password.
+// The TUI should display a password prompt overlay and send the result back.
+type PasswordPromptEvent struct {
+	// Prompt is the message to display to the user.
+	Prompt string
+	// ResponseCh receives the password from the TUI.
+	// The TUI must send exactly one value.
+	ResponseCh chan<- PasswordPromptResponse
+}
+
+// PasswordPromptResponse carries the user's password input.
+type PasswordPromptResponse struct {
+	// Password is the entered password.
+	Password string
+	// Cancelled is true if the user cancelled the prompt.
+	Cancelled bool
+}
+
 // ResponseCompleteEvent is sent when the LLM produces a final (non-streaming) response.
 // In streaming mode, this may be empty if all content was delivered via StreamChunkEvents.
 type ResponseCompleteEvent struct {
@@ -118,8 +171,8 @@ type SpinnerEvent struct {
 // MessageCreatedEvent is sent when a new message is added to the message store.
 // This allows the TUI to stay in sync with the conversation history.
 type MessageCreatedEvent struct {
-	// Message is the fantasy message that was added to the store.
-	Message fantasy.Message
+	// Message is the message that was added to the store.
+	Message kit.LLMMessage
 }
 
 // CompactCompleteEvent is sent when a /compact operation finishes successfully.
@@ -141,6 +194,12 @@ type CompactErrorEvent struct {
 	Err error
 }
 
+// SteerConsumedEvent is sent when one or more steering messages have been
+// consumed — either injected mid-turn via PrepareStep, or drained into the
+// queue after a turn completes. The TUI uses this to clear the steering
+// badge from the display.
+type SteerConsumedEvent struct{}
+
 // ModelChangedEvent is sent when an extension changes the active model via
 // ctx.SetModel. The TUI updates the model name shown in the status bar and
 // message attribution.
@@ -151,11 +210,36 @@ type ModelChangedEvent struct {
 	ModelName string
 }
 
+// UsageUpdatedEvent is sent after each completed LLM step to notify the TUI
+// that token counts and costs have changed. The UsageTracker is updated
+// in-place before this event is sent; the TUI just needs to re-render to
+// reflect the new values in the status bar.
+type UsageUpdatedEvent struct{}
+
 // WidgetUpdateEvent is sent when an extension adds, updates, or removes a
 // widget via ctx.SetWidget or ctx.RemoveWidget. The TUI re-reads widget state
 // from its WidgetProvider on the next render cycle.
 type WidgetUpdateEvent struct{}
 
+// ContentReloadEvent is sent when prompt templates or skills are reloaded
+// from disk (e.g. by a file watcher detecting changes). The TUI refreshes
+// its autocomplete entries and internal state from the provider callbacks.
+type ContentReloadEvent struct{}
+
+// MCPToolsReadyEvent is sent when background MCP tool loading completes.
+// The TUI refreshes its tool names and MCP tool count from provider callbacks
+// so that /tools and the startup info bar reflect the loaded MCP tools.
+type MCPToolsReadyEvent struct{}
+
+// MCPServerLoadedEvent is sent when a single MCP server finishes loading
+// (successfully or with error). The TUI displays a system message so users
+// see real-time progress as each server initializes.
+type MCPServerLoadedEvent struct {
+	ServerName string
+	ToolCount  int
+	Error      error // nil on success
+}
+
 // EditorTextSetEvent is sent when an extension calls ctx.SetEditorText to
 // pre-fill the input editor with text. The TUI handles this by setting the
 // textarea content and moving the cursor to the end.

internal/app/messages.go

@@ -3,31 +3,26 @@ package app
 import (
 	"sync"
 
-	"charm.land/fantasy"
+	kit "github.com/mark3labs/kit/pkg/kit"
 )
 
 // MessageStore is a thread-safe in-memory store for the conversation history.
 // On-disk persistence is handled by the TreeManager at the app/SDK layer.
 type MessageStore struct {
 	mu       sync.RWMutex
-	messages []fantasy.Message
-}
-
-// NewMessageStore creates an empty MessageStore.
-func NewMessageStore() *MessageStore {
-	return &MessageStore{}
+	messages []kit.LLMMessage
 }
 
 // NewMessageStoreWithMessages creates a MessageStore pre-populated with the
 // given messages. This is used when loading an existing session at startup.
-func NewMessageStoreWithMessages(msgs []fantasy.Message) *MessageStore {
-	cp := make([]fantasy.Message, len(msgs))
+func NewMessageStoreWithMessages(msgs []kit.LLMMessage) *MessageStore {
+	cp := make([]kit.LLMMessage, len(msgs))
 	copy(cp, msgs)
 	return &MessageStore{messages: cp}
 }
 
 // Add appends a single message to the store.
-func (s *MessageStore) Add(msg fantasy.Message) {
+func (s *MessageStore) Add(msg kit.LLMMessage) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	s.messages = append(s.messages, msg)
@@ -36,22 +31,22 @@ func (s *MessageStore) Add(msg fantasy.Message) {
 // Replace replaces the entire message history with the given slice. This is
 // used after an agent step returns the full updated conversation (including
 // tool calls and results).
-func (s *MessageStore) Replace(msgs []fantasy.Message) {
+func (s *MessageStore) Replace(msgs []kit.LLMMessage) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 
-	cp := make([]fantasy.Message, len(msgs))
+	cp := make([]kit.LLMMessage, len(msgs))
 	copy(cp, msgs)
 	s.messages = cp
 }
 
 // GetAll returns a snapshot copy of the current message slice.
 // The returned slice is safe to modify without affecting the store.
-func (s *MessageStore) GetAll() []fantasy.Message {
+func (s *MessageStore) GetAll() []kit.LLMMessage {
 	s.mu.RLock()
 	defer s.mu.RUnlock()
 
-	cp := make([]fantasy.Message, len(s.messages))
+	cp := make([]kit.LLMMessage, len(s.messages))
 	copy(cp, s.messages)
 	return cp
 }

internal/app/messages_test.go

@@ -3,23 +3,33 @@ package app
 import (
 	"testing"
 
-	"charm.land/fantasy"
+	kit "github.com/mark3labs/kit/pkg/kit"
 )
 
-// makeTextMsg builds a minimal fantasy.Message with a single TextPart.
-func makeTextMsg(role, text string) fantasy.Message {
-	return fantasy.Message{
-		Role:    fantasy.MessageRole(role),
-		Content: []fantasy.MessagePart{fantasy.TextPart{Text: text}},
+// makeTextMsg builds a minimal kit.LLMMessage with the given role and text.
+func makeTextMsg(role, text string) kit.LLMMessage {
+	return kit.LLMMessage{
+		Role:    kit.LLMMessageRole(role),
+		Content: []kit.LLMMessagePart{kit.LLMTextPart{Text: text}},
 	}
 }
 
+// textOf extracts the plain text from an LLMMessage for assertions.
+func textOf(msg kit.LLMMessage) string {
+	for _, part := range msg.Content {
+		if tp, ok := part.(kit.LLMTextPart); ok {
+			return tp.Text
+		}
+	}
+	return ""
+}
+
 // --------------------------------------------------------------------------
 // NewMessageStore / NewMessageStoreWithMessages
 // --------------------------------------------------------------------------
 
 func TestNewMessageStore_empty(t *testing.T) {
-	s := NewMessageStore()
+	s := NewMessageStoreWithMessages(nil)
 	if s == nil {
 		t.Fatal("expected non-nil store")
 	}
@@ -29,7 +39,7 @@ func TestNewMessageStore_empty(t *testing.T) {
 }
 
 func TestNewMessageStoreWithMessages_preloaded(t *testing.T) {
-	msgs := []fantasy.Message{
+	msgs := []kit.LLMMessage{
 		makeTextMsg("user", "hello"),
 		makeTextMsg("assistant", "hi"),
 	}
@@ -42,7 +52,7 @@ func TestNewMessageStoreWithMessages_preloaded(t *testing.T) {
 // NewMessageStoreWithMessages must deep-copy the slice so that external
 // modifications don't affect the store.
 func TestNewMessageStoreWithMessages_isolatesInput(t *testing.T) {
-	msgs := []fantasy.Message{makeTextMsg("user", "hello")}
+	msgs := []kit.LLMMessage{makeTextMsg("user", "hello")}
 	s := NewMessageStoreWithMessages(msgs)
 
 	// Mutate the source slice.
@@ -52,9 +62,8 @@ func TestNewMessageStoreWithMessages_isolatesInput(t *testing.T) {
 	if len(got) != 1 {
 		t.Fatalf("expected 1 message, got %d", len(got))
 	}
-	tp, ok := got[0].Content[0].(fantasy.TextPart)
-	if !ok || tp.Text != "hello" {
-		t.Fatalf("store was mutated by external slice change; got %q", tp.Text)
+	if textOf(got[0]) != "hello" {
+		t.Fatalf("store was mutated by external slice change; got %q", textOf(got[0]))
 	}
 }
 
@@ -63,7 +72,7 @@ func TestNewMessageStoreWithMessages_isolatesInput(t *testing.T) {
 // --------------------------------------------------------------------------
 
 func TestAdd_appendsMessage(t *testing.T) {
-	s := NewMessageStore()
+	s := NewMessageStoreWithMessages(nil)
 	s.Add(makeTextMsg("user", "first"))
 	s.Add(makeTextMsg("assistant", "second"))
 
@@ -73,16 +82,15 @@ func TestAdd_appendsMessage(t *testing.T) {
 }
 
 func TestAdd_preservesOrder(t *testing.T) {
-	s := NewMessageStore()
+	s := NewMessageStoreWithMessages(nil)
 	texts := []string{"a", "b", "c"}
 	for _, t2 := range texts {
 		s.Add(makeTextMsg("user", t2))
 	}
 	got := s.GetAll()
 	for i, expected := range texts {
-		tp, ok := got[i].Content[0].(fantasy.TextPart)
-		if !ok || tp.Text != expected {
-			t.Fatalf("message[%d]: expected %q, got %q", i, expected, tp.Text)
+		if textOf(got[i]) != expected {
+			t.Fatalf("message[%d]: expected %q, got %q", i, expected, textOf(got[i]))
 		}
 	}
 }
@@ -92,10 +100,10 @@ func TestAdd_preservesOrder(t *testing.T) {
 // --------------------------------------------------------------------------
 
 func TestReplace_swapsHistory(t *testing.T) {
-	s := NewMessageStore()
+	s := NewMessageStoreWithMessages(nil)
 	s.Add(makeTextMsg("user", "old"))
 
-	replacement := []fantasy.Message{
+	replacement := []kit.LLMMessage{
 		makeTextMsg("user", "new1"),
 		makeTextMsg("assistant", "new2"),
 	}
@@ -105,25 +113,22 @@ func TestReplace_swapsHistory(t *testing.T) {
 		t.Fatalf("expected 2 messages after replace, got %d", s.Len())
 	}
 	got := s.GetAll()
-	tp0, _ := got[0].Content[0].(fantasy.TextPart)
-	tp1, _ := got[1].Content[0].(fantasy.TextPart)
-	if tp0.Text != "new1" || tp1.Text != "new2" {
-		t.Fatalf("unexpected messages after replace: %q %q", tp0.Text, tp1.Text)
+	if textOf(got[0]) != "new1" || textOf(got[1]) != "new2" {
+		t.Fatalf("unexpected messages after replace: %q %q", textOf(got[0]), textOf(got[1]))
 	}
 }
 
 // Replace must deep-copy the incoming slice.
 func TestReplace_isolatesInput(t *testing.T) {
-	s := NewMessageStore()
-	replacement := []fantasy.Message{makeTextMsg("user", "original")}
+	s := NewMessageStoreWithMessages(nil)
+	replacement := []kit.LLMMessage{makeTextMsg("user", "original")}
 	s.Replace(replacement)
 
 	replacement[0] = makeTextMsg("user", "mutated")
 
 	got := s.GetAll()
-	tp, _ := got[0].Content[0].(fantasy.TextPart)
-	if tp.Text != "original" {
-		t.Fatalf("store was mutated by external slice change after Replace; got %q", tp.Text)
+	if textOf(got[0]) != "original" {
+		t.Fatalf("store was mutated by external slice change after Replace; got %q", textOf(got[0]))
 	}
 }
 
@@ -132,7 +137,7 @@ func TestReplace_isolatesInput(t *testing.T) {
 // --------------------------------------------------------------------------
 
 func TestGetAll_returnsCopy(t *testing.T) {
-	s := NewMessageStore()
+	s := NewMessageStoreWithMessages(nil)
 	s.Add(makeTextMsg("user", "hello"))
 
 	got := s.GetAll()
@@ -140,14 +145,13 @@ func TestGetAll_returnsCopy(t *testing.T) {
 	got[0] = makeTextMsg("user", "mutated")
 
 	internal := s.GetAll()
-	tp, _ := internal[0].Content[0].(fantasy.TextPart)
-	if tp.Text != "hello" {
-		t.Fatalf("GetAll returned non-copy; store was mutated to %q", tp.Text)
+	if textOf(internal[0]) != "hello" {
+		t.Fatalf("GetAll returned non-copy; store was mutated to %q", textOf(internal[0]))
 	}
 }
 
 func TestGetAll_emptyStore(t *testing.T) {
-	s := NewMessageStore()
+	s := NewMessageStoreWithMessages(nil)
 	got := s.GetAll()
 	if len(got) != 0 {
 		t.Fatalf("expected empty slice, got %d elements", len(got))
@@ -159,7 +163,7 @@ func TestGetAll_emptyStore(t *testing.T) {
 // --------------------------------------------------------------------------
 
 func TestClear_removesAllMessages(t *testing.T) {
-	s := NewMessageStore()
+	s := NewMessageStoreWithMessages(nil)
 	s.Add(makeTextMsg("user", "a"))
 	s.Add(makeTextMsg("user", "b"))
 	s.Clear()
@@ -170,7 +174,7 @@ func TestClear_removesAllMessages(t *testing.T) {
 }
 
 func TestClear_allowsSubsequentAdds(t *testing.T) {
-	s := NewMessageStore()
+	s := NewMessageStoreWithMessages(nil)
 	s.Add(makeTextMsg("user", "before"))
 	s.Clear()
 	s.Add(makeTextMsg("user", "after"))
@@ -179,9 +183,8 @@ func TestClear_allowsSubsequentAdds(t *testing.T) {
 		t.Fatalf("expected 1 message after Clear+Add, got %d", s.Len())
 	}
 	got := s.GetAll()
-	tp, _ := got[0].Content[0].(fantasy.TextPart)
-	if tp.Text != "after" {
-		t.Fatalf("expected %q, got %q", "after", tp.Text)
+	if textOf(got[0]) != "after" {
+		t.Fatalf("expected %q, got %q", "after", textOf(got[0]))
 	}
 }
 
@@ -190,7 +193,7 @@ func TestClear_allowsSubsequentAdds(t *testing.T) {
 // --------------------------------------------------------------------------
 
 func TestConcurrentAccess(t *testing.T) {
-	s := NewMessageStore()
+	s := NewMessageStoreWithMessages(nil)
 	done := make(chan struct{})
 
 	// Writer goroutine.

internal/app/options.go

@@ -21,8 +21,10 @@ type UsageUpdater interface {
 	// the provider does not return exact counts.
 	EstimateAndUpdateUsage(inputText, outputText string)
 	// SetContextTokens records the approximate current context window fill
-	// level. This should be the final API call's input+output tokens (from
-	// FinalResponse.Usage), NOT the aggregate TotalUsage.
+	// level. This should be the sum of ALL token categories from the last
+	// API call: InputTokens + CacheReadTokens + CacheCreationTokens +
+	// OutputTokens. With Anthropic prompt caching, InputTokens can be
+	// near-zero while CacheReadTokens holds the bulk of the context.
 	SetContextTokens(tokens int)
 }
 
@@ -67,10 +69,6 @@ type Options struct {
 	// Debug enables verbose debug logging.
 	Debug bool
 
-	// CompactMode selects the compact renderer instead of the block renderer for
-	// message formatting.
-	CompactMode bool
-
 	// UsageTracker is an optional callback for recording token usage after each
 	// agent step. When non-nil, the app layer calls UpdateUsage (or
 	// EstimateAndUpdateUsage as a fallback) using the usage data returned by the

internal/auth/credentials.go

@@ -1,6 +1,7 @@
 package auth
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"os"
@@ -9,10 +10,11 @@ import (
 	"time"
 )
 
-// CredentialStore holds all stored credentials for various providers.
-// Currently supports Anthropic credentials with both OAuth and API key authentication methods.
+// CredentialStore holds stored credentials for Anthropic, OpenAI, and GitHub Copilot.
 type CredentialStore struct {
 	Anthropic *AnthropicCredentials `json:"anthropic,omitempty"`
+	OpenAI    *OpenAICredentials    `json:"openai,omitempty"`
+	Copilot   *CopilotCredentials   `json:"copilot,omitempty"`
 }
 
 // AnthropicCredentials holds Anthropic API credentials supporting both OAuth
@@ -28,13 +30,54 @@ type AnthropicCredentials struct {
 	CreatedAt    time.Time `json:"created_at"`
 }
 
+// OpenAICredentials holds OpenAI API credentials supporting both OAuth
+// and API key authentication methods. The Type field indicates which authentication
+// method is being used. For OAuth, tokens are stored with expiration timestamps
+// for automatic refresh. For API keys, only the key itself is stored.
+type OpenAICredentials struct {
+	Type         string    `json:"type"`                    // "oauth" or "api_key"
+	APIKey       string    `json:"api_key,omitempty"`       // For API key auth
+	AccessToken  string    `json:"access_token,omitempty"`  // For OAuth
+	RefreshToken string    `json:"refresh_token,omitempty"` // For OAuth
+	ExpiresAt    int64     `json:"expires_at,omitempty"`    // For OAuth
+	AccountID    string    `json:"account_id,omitempty"`    // For OAuth (ChatGPT account ID)
+	CreatedAt    time.Time `json:"created_at"`
+}
+
+// CopilotCredentials holds GitHub OAuth credentials and the short-lived
+// GitHub Copilot API token derived from them.
+type CopilotCredentials struct {
+	Type               string    `json:"type"`                           // "oauth"
+	GitHubToken        string    `json:"github_token,omitempty"`         // GitHub device-flow OAuth token
+	CopilotAccessToken string    `json:"copilot_access_token,omitempty"` // Short-lived Copilot API token
+	ExpiresAt          int64     `json:"expires_at,omitempty"`           // Copilot token expiry
+	CreatedAt          time.Time `json:"created_at"`
+}
+
+// oauthTokenExpired reports whether an OAuth token with the given type and
+// expiry unix timestamp is past its expiry. Returns false for API key
+// credentials or when no expiry is set.
+func oauthTokenExpired(credType string, expiresAt int64) bool {
+	if credType != "oauth" || expiresAt == 0 {
+		return false
+	}
+	return time.Now().Unix() >= expiresAt
+}
+
+// oauthTokenNeedsRefresh reports whether an OAuth token will expire within the
+// next 5 minutes, allowing proactive refresh before it becomes invalid.
+// Returns false for API key credentials or when no expiry is set.
+func oauthTokenNeedsRefresh(credType string, expiresAt int64) bool {
+	if credType != "oauth" || expiresAt == 0 {
+		return false
+	}
+	return time.Now().Unix() >= (expiresAt - 300) // 5 minutes buffer
+}
+
 // IsExpired checks if the OAuth token is expired based on the ExpiresAt timestamp.
 // Returns false for API key authentication or if no expiration is set.
 func (c *AnthropicCredentials) IsExpired() bool {
-	if c.Type != "oauth" || c.ExpiresAt == 0 {
-		return false
-	}
-	return time.Now().Unix() >= c.ExpiresAt
+	return oauthTokenExpired(c.Type, c.ExpiresAt)
 }
 
 // NeedsRefresh checks if the OAuth token needs refresh, returning true if the token
@@ -42,10 +85,31 @@ func (c *AnthropicCredentials) IsExpired() bool {
 // to avoid authentication failures during operations. Returns false for API key
 // authentication or if no expiration is set.
 func (c *AnthropicCredentials) NeedsRefresh() bool {
-	if c.Type != "oauth" || c.ExpiresAt == 0 {
-		return false
-	}
-	return time.Now().Unix() >= (c.ExpiresAt - 300) // 5 minutes buffer
+	return oauthTokenNeedsRefresh(c.Type, c.ExpiresAt)
+}
+
+// IsExpired checks if the OAuth token is expired based on the ExpiresAt timestamp.
+// Returns false for API key authentication or if no expiration is set.
+func (c *OpenAICredentials) IsExpired() bool {
+	return oauthTokenExpired(c.Type, c.ExpiresAt)
+}
+
+// NeedsRefresh checks if the OAuth token needs refresh, returning true if the token
+// will expire within the next 5 minutes. This allows for proactive token refresh
+// to avoid authentication failures during operations. Returns false for API key
+// authentication or if no expiration is set.
+func (c *OpenAICredentials) NeedsRefresh() bool {
+	return oauthTokenNeedsRefresh(c.Type, c.ExpiresAt)
+}
+
+// IsExpired checks if the Copilot API token is expired.
+func (c *CopilotCredentials) IsExpired() bool {
+	return oauthTokenExpired(c.Type, c.ExpiresAt)
+}
+
+// NeedsRefresh reports whether the Copilot API token should be renewed.
+func (c *CopilotCredentials) NeedsRefresh() bool {
+	return oauthTokenNeedsRefresh(c.Type, c.ExpiresAt)
 }
 
 // CredentialManager handles secure storage and retrieval of authentication credentials.
@@ -179,7 +243,7 @@ func (cm *CredentialManager) RemoveAnthropicCredentials() error {
 	store.Anthropic = nil
 
 	// If store is empty, remove the file entirely
-	if store.Anthropic == nil {
+	if store.Anthropic == nil && store.OpenAI == nil && store.Copilot == nil {
 		if err := os.Remove(cm.credentialsPath); err != nil && !os.IsNotExist(err) {
 			return fmt.Errorf("failed to remove credentials file: %w", err)
 		}
@@ -212,6 +276,217 @@ func (cm *CredentialManager) HasAnthropicCredentials() (bool, error) {
 	}
 }
 
+// GetOpenAICredentials retrieves stored OpenAI credentials. Returns nil if
+// no credentials are stored. The returned credentials may be either OAuth or API
+// key type, check the Type field to determine which.
+func (cm *CredentialManager) GetOpenAICredentials() (*OpenAICredentials, error) {
+	store, err := cm.LoadCredentials()
+	if err != nil {
+		return nil, err
+	}
+
+	return store.OpenAI, nil
+}
+
+// RemoveOpenAICredentials removes stored OpenAI credentials from storage.
+// If this was the only credential stored, the entire credentials file is removed.
+// Returns an error if the removal fails.
+func (cm *CredentialManager) RemoveOpenAICredentials() error {
+	store, err := cm.LoadCredentials()
+	if err != nil {
+		return err
+	}
+
+	store.OpenAI = nil
+
+	// If store is empty, remove the file entirely
+	if store.Anthropic == nil && store.OpenAI == nil && store.Copilot == nil {
+		if err := os.Remove(cm.credentialsPath); err != nil && !os.IsNotExist(err) {
+			return fmt.Errorf("failed to remove credentials file: %w", err)
+		}
+		return nil
+	}
+
+	return cm.SaveCredentials(store)
+}
+
+// GetCopilotCredentials retrieves stored GitHub Copilot credentials.
+func (cm *CredentialManager) GetCopilotCredentials() (*CopilotCredentials, error) {
+	store, err := cm.LoadCredentials()
+	if err != nil {
+		return nil, err
+	}
+
+	return store.Copilot, nil
+}
+
+// RemoveCopilotCredentials removes stored GitHub Copilot credentials.
+func (cm *CredentialManager) RemoveCopilotCredentials() error {
+	store, err := cm.LoadCredentials()
+	if err != nil {
+		return err
+	}
+
+	store.Copilot = nil
+
+	if store.Anthropic == nil && store.OpenAI == nil && store.Copilot == nil {
+		if err := os.Remove(cm.credentialsPath); err != nil && !os.IsNotExist(err) {
+			return fmt.Errorf("failed to remove credentials file: %w", err)
+		}
+		return nil
+	}
+
+	return cm.SaveCredentials(store)
+}
+
+// HasCopilotCredentials checks if valid GitHub Copilot credentials are stored.
+func (cm *CredentialManager) HasCopilotCredentials() (bool, error) {
+	creds, err := cm.GetCopilotCredentials()
+	if err != nil {
+		return false, err
+	}
+	if creds == nil {
+		return false, nil
+	}
+
+	return creds.Type == "oauth" && creds.GitHubToken != "", nil
+}
+
+// SetCopilotOAuthCredentials stores GitHub Copilot OAuth credentials.
+func (cm *CredentialManager) SetCopilotOAuthCredentials(creds *CopilotCredentials) error {
+	store, err := cm.LoadCredentials()
+	if err != nil {
+		return err
+	}
+
+	store.Copilot = creds
+	return cm.SaveCredentials(store)
+}
+
+// GetValidCopilotAccessToken returns a fresh Copilot API token, renewing it
+// with the stored GitHub OAuth token when needed.
+func (cm *CredentialManager) GetValidCopilotAccessToken() (string, error) {
+	return cm.GetValidCopilotAccessTokenContext(context.Background())
+}
+
+// GetValidCopilotAccessTokenContext returns a fresh Copilot API token, renewing
+// it with the stored GitHub OAuth token when needed.
+func (cm *CredentialManager) GetValidCopilotAccessTokenContext(ctx context.Context) (string, error) {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+
+	creds, err := cm.GetCopilotCredentials()
+	if err != nil {
+		return "", err
+	}
+	if creds == nil {
+		return "", fmt.Errorf("no Copilot credentials found")
+	}
+	if creds.Type != "oauth" {
+		return "", fmt.Errorf("unknown credential type: %s", creds.Type)
+	}
+	if creds.GitHubToken == "" {
+		return "", fmt.Errorf("GitHub OAuth token missing from Copilot credentials")
+	}
+
+	if creds.CopilotAccessToken == "" || creds.NeedsRefresh() {
+		client := NewCopilotOAuthClient()
+		newCreds, err := client.RefreshCopilotToken(ctx, creds.GitHubToken)
+		if err != nil {
+			return "", fmt.Errorf("failed to refresh Copilot token: %w", err)
+		}
+		newCreds.CreatedAt = creds.CreatedAt
+
+		if err := cm.SetCopilotOAuthCredentials(newCreds); err != nil {
+			return "", fmt.Errorf("failed to save refreshed Copilot token: %w", err)
+		}
+
+		return newCreds.CopilotAccessToken, nil
+	}
+
+	return creds.CopilotAccessToken, nil
+}
+
+// HasOpenAICredentials checks if valid OpenAI credentials are stored.
+// Returns true if either a non-empty OAuth access token or API key is present,
+// false otherwise. Returns an error if credentials cannot be loaded.
+func (cm *CredentialManager) HasOpenAICredentials() (bool, error) {
+	creds, err := cm.GetOpenAICredentials()
+	if err != nil {
+		return false, err
+	}
+	if creds == nil {
+		return false, nil
+	}
+
+	// Check based on credential type
+	switch creds.Type {
+	case "oauth":
+		return creds.AccessToken != "", nil
+	case "api_key":
+		return creds.APIKey != "", nil
+	default:
+		return false, nil
+	}
+}
+
+// SetOpenAIOAuthCredentials stores OpenAI OAuth credentials in the credential manager's secure storage.
+// The credentials should include access token, refresh token, and expiration information.
+// Returns an error if the credentials cannot be saved.
+func (cm *CredentialManager) SetOpenAIOAuthCredentials(creds *OpenAICredentials) error {
+	store, err := cm.LoadCredentials()
+	if err != nil {
+		return err
+	}
+
+	store.OpenAI = creds
+	return cm.SaveCredentials(store)
+}
+
+// GetValidOpenAIAccessToken returns a valid access token for API requests. For OAuth credentials,
+// it automatically refreshes the token if it's expired or about to expire. For API key
+// credentials, it simply returns the API key. Returns an error if no credentials are found,
+// if token refresh fails, or if the credential type is unknown.
+func (cm *CredentialManager) GetValidOpenAIAccessToken() (string, error) {
+	creds, err := cm.GetOpenAICredentials()
+	if err != nil {
+		return "", err
+	}
+
+	if creds == nil {
+		return "", fmt.Errorf("no credentials found")
+	}
+
+	// For API key auth, return the API key
+	if creds.Type == "api_key" {
+		return creds.APIKey, nil
+	}
+
+	// For OAuth, check if token needs refresh
+	if creds.Type == "oauth" {
+		if creds.NeedsRefresh() {
+			// Refresh the token
+			client := NewOpenAIOAuthClient()
+			newCreds, err := client.RefreshToken(creds.RefreshToken)
+			if err != nil {
+				return "", fmt.Errorf("failed to refresh token: %w", err)
+			}
+
+			// Update stored credentials
+			if err := cm.SetOpenAIOAuthCredentials(newCreds); err != nil {
+				return "", fmt.Errorf("failed to save refreshed token: %w", err)
+			}
+
+			return newCreds.AccessToken, nil
+		}
+
+		return creds.AccessToken, nil
+	}
+
+	return "", fmt.Errorf("unknown credential type: %s", creds.Type)
+}
+
 // GetCredentialsPath returns the absolute path to the credentials JSON file.
 // This is useful for debugging or displaying the storage location to users.
 func (cm *CredentialManager) GetCredentialsPath() string {
@@ -238,6 +513,20 @@ func validateAnthropicAPIKey(apiKey string) error {
 	return nil
 }
 
+// CredentialSourceOAuth is the source description returned by
+// GetAnthropicAPIKey when the key resolves to stored OAuth credentials.
+// Consumers should compare against this constant (or use IsAnthropicOAuth)
+// rather than matching the string literal.
+const CredentialSourceOAuth = "stored OAuth credentials"
+
+// IsAnthropicOAuth reports whether the active Anthropic credential resolves
+// to a stored OAuth token (in which case the user is not billed per-token).
+// flagValue is the --provider-api-key flag value (may be empty).
+func IsAnthropicOAuth(flagValue string) bool {
+	_, source, err := GetAnthropicAPIKey(flagValue)
+	return err == nil && source == CredentialSourceOAuth
+}
+
 // GetAnthropicAPIKey retrieves an Anthropic API key from multiple sources in priority order:
 // 1. Command-line flag value (highest priority)
 // 2. Stored credentials (OAuth or API key)
@@ -260,7 +549,7 @@ func GetAnthropicAPIKey(flagValue string) (string, string, error) {
 				if err != nil {
 					return "", "", fmt.Errorf("failed to get valid OAuth token: %w", err)
 				}
-				return token, "stored OAuth credentials", nil
+				return token, CredentialSourceOAuth, nil
 			} else if creds.Type == "api_key" && creds.APIKey != "" {
 				return creds.APIKey, "stored API key", nil
 			}
@@ -272,5 +561,13 @@ func GetAnthropicAPIKey(flagValue string) (string, string, error) {
 		return envKey, "ANTHROPIC_API_KEY environment variable", nil
 	}
 
+	// Check if OpenAI credentials exist to provide a helpful suggestion
+	if cm != nil {
+		hasOpenAI, _ := cm.HasOpenAICredentials()
+		if hasOpenAI {
+			return "", "", fmt.Errorf("no Anthropic API key found. Use 'kit auth login anthropic', set ANTHROPIC_API_KEY environment variable, or use --provider-api-key flag\n\nNote: OpenAI credentials were detected. To use OpenAI, run with --model openai/gpt-5.4 or set it as default:\n  kit auth login openai --set-default")
+		}
+	}
+
 	return "", "", fmt.Errorf("no Anthropic API key found. Use 'kit auth login anthropic', set ANTHROPIC_API_KEY environment variable, or use --provider-api-key flag")
 }

internal/auth/credentials_test.go

@@ -4,6 +4,7 @@ import (
 	"os"
 	"path/filepath"
 	"testing"
+	"time"
 )
 
 func TestCredentialManager(t *testing.T) {
@@ -215,6 +216,7 @@ func TestCredentialStorePersistence(t *testing.T) {
 	if err != nil {
 		t.Fatalf("Failed to create temp dir: %v", err)
 	}
+
 	defer func() { _ = os.RemoveAll(tempDir) }()
 
 	credentialsPath := filepath.Join(tempDir, "credentials.json")
@@ -252,3 +254,98 @@ func TestCredentialStorePersistence(t *testing.T) {
 		t.Errorf("Expected file permissions 0600, got %v", info.Mode().Perm())
 	}
 }
+
+func TestCopilotCredentials(t *testing.T) {
+	tempDir, err := os.MkdirTemp("", "kit-auth-test")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer func() { _ = os.RemoveAll(tempDir) }()
+
+	cm := &CredentialManager{
+		credentialsPath: filepath.Join(tempDir, "credentials.json"),
+	}
+
+	creds := &CopilotCredentials{
+		Type:               "oauth",
+		GitHubToken:        "github-token",
+		CopilotAccessToken: "copilot-token",
+		ExpiresAt:          time.Now().Add(time.Hour).Unix(),
+		CreatedAt:          time.Now(),
+	}
+
+	if err := cm.SetCopilotOAuthCredentials(creds); err != nil {
+		t.Fatalf("SetCopilotOAuthCredentials failed: %v", err)
+	}
+
+	hasAuth, err := cm.HasCopilotCredentials()
+	if err != nil {
+		t.Fatalf("HasCopilotCredentials failed: %v", err)
+	}
+	if !hasAuth {
+		t.Fatal("Expected Copilot credentials")
+	}
+
+	token, err := cm.GetValidCopilotAccessToken()
+	if err != nil {
+		t.Fatalf("GetValidCopilotAccessToken failed: %v", err)
+	}
+	if token != creds.CopilotAccessToken {
+		t.Fatalf("Expected Copilot token %q, got %q", creds.CopilotAccessToken, token)
+	}
+
+	if err := cm.RemoveCopilotCredentials(); err != nil {
+		t.Fatalf("RemoveCopilotCredentials failed: %v", err)
+	}
+	hasAuth, err = cm.HasCopilotCredentials()
+	if err != nil {
+		t.Fatalf("HasCopilotCredentials after removal failed: %v", err)
+	}
+	if hasAuth {
+		t.Fatal("Expected no Copilot credentials after removal")
+	}
+}
+
+func TestRemoveCredentialsPreservesOtherProviders(t *testing.T) {
+	tempDir, err := os.MkdirTemp("", "kit-auth-test")
+	if err != nil {
+		t.Fatalf("Failed to create temp dir: %v", err)
+	}
+	defer func() { _ = os.RemoveAll(tempDir) }()
+
+	cm := &CredentialManager{
+		credentialsPath: filepath.Join(tempDir, "credentials.json"),
+	}
+
+	if err := cm.SetOpenAIOAuthCredentials(&OpenAICredentials{
+		Type:         "oauth",
+		AccessToken:  "openai-token",
+		RefreshToken: "refresh-token",
+		ExpiresAt:    time.Now().Add(time.Hour).Unix(),
+		AccountID:    "account",
+		CreatedAt:    time.Now(),
+	}); err != nil {
+		t.Fatalf("SetOpenAIOAuthCredentials failed: %v", err)
+	}
+	if err := cm.SetCopilotOAuthCredentials(&CopilotCredentials{
+		Type:               "oauth",
+		GitHubToken:        "github-token",
+		CopilotAccessToken: "copilot-token",
+		ExpiresAt:          time.Now().Add(time.Hour).Unix(),
+		CreatedAt:          time.Now(),
+	}); err != nil {
+		t.Fatalf("SetCopilotOAuthCredentials failed: %v", err)
+	}
+
+	if err := cm.RemoveCopilotCredentials(); err != nil {
+		t.Fatalf("RemoveCopilotCredentials failed: %v", err)
+	}
+
+	hasOpenAI, err := cm.HasOpenAICredentials()
+	if err != nil {
+		t.Fatalf("HasOpenAICredentials failed: %v", err)
+	}
+	if !hasOpenAI {
+		t.Fatal("Expected OpenAI credentials to remain after removing Copilot credentials")
+	}
+}

internal/auth/oauth.go

@@ -7,8 +7,10 @@ import (
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
+	"io"
 	"net/http"
 	"net/url"
+	"strconv"
 	"strings"
 	"time"
 )
@@ -30,6 +32,7 @@ type OAuthClient struct {
 type AuthData struct {
 	URL      string
 	Verifier string
+	State    string // Optional state parameter for CSRF protection
 }
 
 // NewOAuthClient creates a new OAuth client configured for Anthropic's OAuth service.
@@ -199,6 +202,526 @@ func (c *OAuthClient) parseCodeAndState(code string) (parsedCode, parsedState st
 	return
 }
 
+// OpenAIOAuthClient handles OAuth 2.0 authentication flow with OpenAI Codex (ChatGPT Plus/Pro).
+// This uses OpenAI's auth0-based OAuth service for ChatGPT account authentication.
+type OpenAIOAuthClient struct {
+	ClientID     string
+	AuthorizeURL string
+	TokenURL     string
+	RedirectURI  string
+	Scopes       string
+}
+
+// CopilotOAuthClient handles GitHub device-flow OAuth and exchanges the
+// GitHub token for a short-lived GitHub Copilot API token.
+//
+// The GitHub token comes from GitHub's OAuth device flow. It is then presented
+// to GitHub's internal Copilot token endpoint, which returns the bearer token
+// used by api.githubcopilot.com.
+type CopilotOAuthClient struct {
+	ClientID      string
+	DeviceURL     string
+	TokenURL      string
+	CopilotURL    string
+	Scopes        string
+	PollTimeout   time.Duration
+	ClientTimeout time.Duration
+}
+
+// CopilotDeviceCode contains data returned by GitHub's device-code endpoint.
+type CopilotDeviceCode struct {
+	DeviceCode      string `json:"device_code"`
+	UserCode        string `json:"user_code"`
+	VerificationURI string `json:"verification_uri"`
+	ExpiresIn       int    `json:"expires_in"`
+	Interval        int    `json:"interval"`
+}
+
+// NewCopilotOAuthClient creates a GitHub Copilot OAuth client.
+func NewCopilotOAuthClient() *CopilotOAuthClient {
+	return &CopilotOAuthClient{
+		ClientID:      "Iv1.b507a08c87ecfe98",
+		DeviceURL:     "https://github.com/login/device/code",
+		TokenURL:      "https://github.com/login/oauth/access_token",
+		CopilotURL:    "https://api.github.com/copilot_internal/v2/token",
+		Scopes:        "read:user",
+		PollTimeout:   15 * time.Minute,
+		ClientTimeout: 30 * time.Second,
+	}
+}
+
+// StartDeviceFlow requests a GitHub device code for browser login.
+//
+// The returned user code and verification URI are displayed by loginCopilot.
+// GitHub's response may omit interval, so this method normalizes it to the
+// documented five-second default.
+func (c *CopilotOAuthClient) StartDeviceFlow(ctx context.Context) (*CopilotDeviceCode, error) {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+
+	data := url.Values{
+		"client_id": {c.ClientID},
+		"scope":     {c.Scopes},
+	}
+
+	req, err := http.NewRequestWithContext(ctx, "POST", c.DeviceURL, strings.NewReader(data.Encode()))
+	if err != nil {
+		return nil, fmt.Errorf("failed to create device-code request: %w", err)
+	}
+	req.Header.Set("Accept", "application/json")
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+
+	resp, err := (&http.Client{Timeout: c.ClientTimeout}).Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to request device code: %w", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		return nil, fmt.Errorf("device-code request failed with status %d: %s", resp.StatusCode, string(body))
+	}
+
+	var code CopilotDeviceCode
+	if err := json.NewDecoder(resp.Body).Decode(&code); err != nil {
+		return nil, fmt.Errorf("failed to decode device-code response: %w", err)
+	}
+	if code.DeviceCode == "" || code.UserCode == "" || code.VerificationURI == "" {
+		return nil, fmt.Errorf("device-code response missing required fields")
+	}
+	if code.Interval <= 0 {
+		code.Interval = 5
+	}
+	return &code, nil
+}
+
+// PollDeviceToken waits until the user authorizes the device code and returns
+// the resulting GitHub OAuth token.
+//
+// It follows GitHub's device-flow polling contract: authorization_pending keeps
+// polling, slow_down increases the interval, and polling stops at the earlier of
+// the client timeout or the device-code expiry.
+func (c *CopilotOAuthClient) PollDeviceToken(ctx context.Context, deviceCode *CopilotDeviceCode) (string, error) {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+
+	if deviceCode == nil || deviceCode.DeviceCode == "" {
+		return "", fmt.Errorf("device code missing")
+	}
+
+	deadline := time.Now().Add(c.PollTimeout)
+	if deviceCode.ExpiresIn > 0 {
+		expiresAt := time.Now().Add(time.Duration(deviceCode.ExpiresIn) * time.Second)
+		if expiresAt.Before(deadline) {
+			deadline = expiresAt
+		}
+	}
+
+	interval := time.Duration(deviceCode.Interval) * time.Second
+	if interval <= 0 {
+		interval = 5 * time.Second
+	}
+
+	for time.Now().Before(deadline) {
+		wait := interval
+		if remaining := time.Until(deadline); remaining < wait {
+			wait = remaining
+		}
+		select {
+		case <-ctx.Done():
+			return "", ctx.Err()
+		case <-time.After(wait):
+		}
+
+		data := url.Values{
+			"client_id":   {c.ClientID},
+			"device_code": {deviceCode.DeviceCode},
+			"grant_type":  {"urn:ietf:params:oauth:grant-type:device_code"},
+		}
+
+		req, err := http.NewRequestWithContext(ctx, "POST", c.TokenURL, strings.NewReader(data.Encode()))
+		if err != nil {
+			return "", fmt.Errorf("failed to create device-token request: %w", err)
+		}
+		req.Header.Set("Accept", "application/json")
+		req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+
+		resp, err := (&http.Client{Timeout: c.ClientTimeout}).Do(req)
+		if err != nil {
+			return "", fmt.Errorf("failed to poll device token: %w", err)
+		}
+
+		var tokenResp struct {
+			AccessToken string `json:"access_token"`
+			Error       string `json:"error"`
+			Description string `json:"error_description"`
+		}
+		decodeErr := json.NewDecoder(resp.Body).Decode(&tokenResp)
+		_ = resp.Body.Close()
+		if decodeErr != nil {
+			return "", fmt.Errorf("failed to decode device-token response: %w", decodeErr)
+		}
+
+		if tokenResp.AccessToken != "" {
+			return tokenResp.AccessToken, nil
+		}
+
+		switch tokenResp.Error {
+		case "authorization_pending":
+			continue
+		case "slow_down":
+			interval += 5 * time.Second
+			continue
+		case "expired_token":
+			return "", fmt.Errorf("device code expired; restart login")
+		case "access_denied":
+			return "", fmt.Errorf("github login denied")
+		case "":
+			return "", fmt.Errorf("device-token request failed with status %d", resp.StatusCode)
+		default:
+			if tokenResp.Description != "" {
+				return "", fmt.Errorf("device-token request failed: %s: %s", tokenResp.Error, tokenResp.Description)
+			}
+			return "", fmt.Errorf("device-token request failed: %s", tokenResp.Error)
+		}
+	}
+
+	return "", fmt.Errorf("timed out waiting for github device authorization")
+}
+
+// ExchangeGitHubToken converts a GitHub OAuth token into a Copilot API token.
+// It is a semantic wrapper over RefreshCopilotToken used by the login flow.
+func (c *CopilotOAuthClient) ExchangeGitHubToken(ctx context.Context, githubToken string) (*CopilotCredentials, error) {
+	return c.RefreshCopilotToken(ctx, githubToken)
+}
+
+// RefreshCopilotToken obtains a fresh short-lived Copilot token from GitHub.
+//
+// GitHub may return expires_at as either a Unix timestamp or RFC3339 string.
+// parseCopilotExpiry handles both forms and falls back to a conservative
+// 20-minute lifetime when the field is absent or unrecognized.
+func (c *CopilotOAuthClient) RefreshCopilotToken(ctx context.Context, githubToken string) (*CopilotCredentials, error) {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+
+	req, err := http.NewRequestWithContext(ctx, "GET", c.CopilotURL, nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create copilot token request: %w", err)
+	}
+	req.Header.Set("Authorization", "token "+githubToken)
+	req.Header.Set("Accept", "application/json")
+	req.Header.Set("User-Agent", "kit")
+	req.Header.Set("X-GitHub-Api-Version", "2022-11-28")
+
+	resp, err := (&http.Client{Timeout: c.ClientTimeout}).Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to request copilot token: %w", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		return nil, fmt.Errorf("copilot token request failed with status %d: %s", resp.StatusCode, string(body))
+	}
+
+	var tokenResp struct {
+		Token     string `json:"token"`
+		ExpiresAt any    `json:"expires_at"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&tokenResp); err != nil {
+		return nil, fmt.Errorf("failed to decode copilot token response: %w", err)
+	}
+	if tokenResp.Token == "" {
+		return nil, fmt.Errorf("copilot token response missing token")
+	}
+
+	expiresAt := parseCopilotExpiry(tokenResp.ExpiresAt)
+	if expiresAt == 0 {
+		expiresAt = time.Now().Add(20 * time.Minute).Unix()
+	}
+
+	return &CopilotCredentials{
+		Type:               "oauth",
+		GitHubToken:        githubToken,
+		CopilotAccessToken: tokenResp.Token,
+		ExpiresAt:          expiresAt,
+		CreatedAt:          time.Now(),
+	}, nil
+}
+
+// parseCopilotExpiry normalizes GitHub's expires_at variants to a Unix second.
+func parseCopilotExpiry(value any) int64 {
+	switch v := value.(type) {
+	case float64:
+		return int64(v)
+	case string:
+		if parsed, err := strconv.ParseInt(v, 10, 64); err == nil {
+			return parsed
+		}
+		if parsed, err := time.Parse(time.RFC3339, v); err == nil {
+			return parsed.Unix()
+		}
+	}
+	return 0
+}
+
+// NewOpenAIOAuthClient creates a new OAuth client configured for OpenAI Codex OAuth.
+// This uses the public client ID for CLI applications with PKCE for security.
+func NewOpenAIOAuthClient() *OpenAIOAuthClient {
+	return &OpenAIOAuthClient{
+		// Public client ID for OpenAI Codex CLI OAuth
+		ClientID:     "app_EMoamEEZ73f0CkXaXp7hrann",
+		AuthorizeURL: "https://auth.openai.com/oauth/authorize",
+		TokenURL:     "https://auth.openai.com/oauth/token",
+		RedirectURI:  "http://localhost:1455/auth/callback",
+		Scopes:       "openid profile email offline_access",
+	}
+}
+
+// GetAuthorizationURL generates a complete authorization URL for the OAuth flow with
+// PKCE parameters. Returns an AuthData structure containing the URL for user
+// authentication and the PKCE verifier for the subsequent code exchange.
+func (c *OpenAIOAuthClient) GetAuthorizationURL() (*AuthData, error) {
+	verifier, challenge, err := generatePKCE()
+	if err != nil {
+		return nil, fmt.Errorf("failed to generate PKCE: %w", err)
+	}
+
+	// Generate random state
+	stateBytes := make([]byte, 16)
+	if _, err := rand.Read(stateBytes); err != nil {
+		return nil, fmt.Errorf("failed to generate state: %w", err)
+	}
+	state := fmt.Sprintf("%x", stateBytes)
+
+	params := url.Values{
+		"response_type":              {"code"},
+		"client_id":                  {c.ClientID},
+		"redirect_uri":               {c.RedirectURI},
+		"scope":                      {c.Scopes},
+		"code_challenge":             {challenge},
+		"code_challenge_method":      {"S256"},
+		"state":                      {state},
+		"id_token_add_organizations": {"true"},
+		"codex_cli_simplified_flow":  {"true"},
+		"originator":                 {"kit"},
+	}
+
+	authURL := fmt.Sprintf("%s?%s", c.AuthorizeURL, params.Encode())
+
+	return &AuthData{
+		URL:      authURL,
+		Verifier: verifier,
+		State:    state,
+	}, nil
+}
+
+// ExchangeCode exchanges an authorization code for access and refresh tokens.
+// The code parameter should be the authorization code received from the OAuth callback.
+// The verifier parameter must be the same PKCE verifier generated during GetAuthorizationURL.
+// Returns OpenAICredentials containing the tokens, expiration, and account ID.
+func (c *OpenAIOAuthClient) ExchangeCode(code, verifier string) (*OpenAICredentials, error) {
+	return c.exchangeAuthorizationCode(code, verifier, c.RedirectURI)
+}
+
+// exchangeAuthorizationCode performs the token exchange with the OAuth server
+func (c *OpenAIOAuthClient) exchangeAuthorizationCode(code, verifier, redirectUri string) (*OpenAICredentials, error) {
+	data := url.Values{
+		"grant_type":    {"authorization_code"},
+		"client_id":     {c.ClientID},
+		"code":          {code},
+		"code_verifier": {verifier},
+		"redirect_uri":  {redirectUri},
+	}
+
+	req, err := http.NewRequestWithContext(context.Background(), "POST", c.TokenURL, strings.NewReader(data.Encode()))
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %w", err)
+	}
+
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+
+	client := &http.Client{Timeout: 30 * time.Second}
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to make token request: %w", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		return nil, fmt.Errorf("token exchange failed: %s", string(body))
+	}
+
+	var tokenResp struct {
+		AccessToken  string `json:"access_token"`
+		RefreshToken string `json:"refresh_token"`
+		ExpiresIn    int    `json:"expires_in"`
+		IDToken      string `json:"id_token"`
+	}
+
+	if err := json.NewDecoder(resp.Body).Decode(&tokenResp); err != nil {
+		return nil, fmt.Errorf("failed to decode token response: %w", err)
+	}
+
+	if tokenResp.AccessToken == "" || tokenResp.RefreshToken == "" {
+		return nil, fmt.Errorf("token response missing required fields")
+	}
+
+	// Extract account ID from JWT token
+	accountID := extractOpenAIAccountID(tokenResp.AccessToken)
+	if accountID == "" {
+		return nil, fmt.Errorf("failed to extract account ID from token")
+	}
+
+	return &OpenAICredentials{
+		Type:         "oauth",
+		AccessToken:  tokenResp.AccessToken,
+		RefreshToken: tokenResp.RefreshToken,
+		ExpiresAt:    time.Now().Unix() + int64(tokenResp.ExpiresIn),
+		CreatedAt:    time.Now(),
+		AccountID:    accountID,
+	}, nil
+}
+
+// RefreshToken refreshes an expired or expiring access token using a refresh token.
+// Returns new OpenAICredentials with updated access token, refresh token (may be
+// rotated), and new expiration timestamp. Returns an error if the refresh fails or
+// the refresh token is invalid.
+func (c *OpenAIOAuthClient) RefreshToken(refreshToken string) (*OpenAICredentials, error) {
+	data := url.Values{
+		"grant_type":    {"refresh_token"},
+		"refresh_token": {refreshToken},
+		"client_id":     {c.ClientID},
+	}
+
+	req, err := http.NewRequestWithContext(context.Background(), "POST", c.TokenURL, strings.NewReader(data.Encode()))
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %w", err)
+	}
+
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+
+	client := &http.Client{Timeout: 30 * time.Second}
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to make refresh request: %w", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		return nil, fmt.Errorf("token refresh failed: %s", string(body))
+	}
+
+	var tokenResp struct {
+		AccessToken  string `json:"access_token"`
+		RefreshToken string `json:"refresh_token"`
+		ExpiresIn    int    `json:"expires_in"`
+	}
+
+	if err := json.NewDecoder(resp.Body).Decode(&tokenResp); err != nil {
+		return nil, fmt.Errorf("failed to decode refresh response: %w", err)
+	}
+
+	if tokenResp.AccessToken == "" || tokenResp.RefreshToken == "" {
+		return nil, fmt.Errorf("refresh response missing required fields")
+	}
+
+	// Extract account ID from JWT token
+	accountID := extractOpenAIAccountID(tokenResp.AccessToken)
+	if accountID == "" {
+		return nil, fmt.Errorf("failed to extract account ID from refreshed token")
+	}
+
+	return &OpenAICredentials{
+		Type:         "oauth",
+		AccessToken:  tokenResp.AccessToken,
+		RefreshToken: tokenResp.RefreshToken,
+		ExpiresAt:    time.Now().Unix() + int64(tokenResp.ExpiresIn),
+		CreatedAt:    time.Now(),
+		AccountID:    accountID,
+	}, nil
+}
+
+// extractOpenAIAccountID extracts the ChatGPT account ID from a JWT access token.
+// The account ID is stored in the claim path https://api.openai.com/auth.chatgpt_account_id
+func extractOpenAIAccountID(token string) string {
+	// JWT tokens are base64-encoded JSON payloads
+	parts := strings.Split(token, ".")
+	if len(parts) != 3 {
+		return ""
+	}
+
+	// Decode payload (second part)
+	payload := parts[1]
+	// Add padding if needed
+	if len(payload)%4 != 0 {
+		payload += strings.Repeat("=", 4-len(payload)%4)
+	}
+
+	decoded, err := base64.URLEncoding.DecodeString(payload)
+	if err != nil {
+		return ""
+	}
+
+	var claims map[string]any
+	if err := json.Unmarshal(decoded, &claims); err != nil {
+		return ""
+	}
+
+	// Navigate to the claim path: https://api.openai.com/auth.chatgpt_account_id
+	authPath, ok := claims["https://api.openai.com/auth"].(map[string]any)
+	if !ok {
+		return ""
+	}
+
+	accountID, ok := authPath["chatgpt_account_id"].(string)
+	if !ok {
+		return ""
+	}
+
+	return accountID
+}
+
+// ParseOpenAIAuthorizationInput parses various forms of authorization input:
+// - Full callback URL: http://localhost:1455/auth/callback?code=xxx&state=yyy
+// - Code#State format: abc123#state456
+// - Query string: code=abc123&state=state456
+// - Just the code: abc123
+func ParseOpenAIAuthorizationInput(input string) (code, state string) {
+	input = strings.TrimSpace(input)
+	if input == "" {
+		return "", ""
+	}
+
+	// Try parsing as URL
+	if strings.HasPrefix(input, "http") {
+		if u, err := url.Parse(input); err == nil {
+			return u.Query().Get("code"), u.Query().Get("state")
+		}
+	}
+
+	// Try code#state format
+	if strings.Contains(input, "#") {
+		parts := strings.SplitN(input, "#", 2)
+		return parts[0], parts[1]
+	}
+
+	// Try query string format
+	if strings.Contains(input, "code=") {
+		if values, err := url.ParseQuery(input); err == nil {
+			return values.Get("code"), values.Get("state")
+		}
+	}
+
+	// Assume it's just the code
+	return input, ""
+}
+
 // SetOAuthCredentials stores OAuth credentials in the credential manager's secure storage.
 // The credentials should include access token, refresh token, and expiration information.
 // Returns an error if the credentials cannot be saved.

internal/auth/oauth_test.go

@@ -0,0 +1,124 @@
+package auth
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+)
+
+func TestCopilotStartDeviceFlow(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			t.Fatalf("expected POST, got %s", r.Method)
+		}
+		if err := r.ParseForm(); err != nil {
+			t.Fatalf("ParseForm failed: %v", err)
+		}
+		if r.Form.Get("client_id") != "client-id" {
+			t.Fatalf("expected client id, got %q", r.Form.Get("client_id"))
+		}
+		if r.Form.Get("scope") != "read:user" {
+			t.Fatalf("expected scope, got %q", r.Form.Get("scope"))
+		}
+		_ = json.NewEncoder(w).Encode(map[string]any{
+			"device_code":      "device-code",
+			"user_code":        "USER-CODE",
+			"verification_uri": "https://github.com/login/device",
+			"expires_in":       600,
+			"interval":         1,
+		})
+	}))
+	defer server.Close()
+
+	client := NewCopilotOAuthClient()
+	client.ClientID = "client-id"
+	client.DeviceURL = server.URL
+
+	code, err := client.StartDeviceFlow(context.Background())
+	if err != nil {
+		t.Fatalf("StartDeviceFlow failed: %v", err)
+	}
+	if code.DeviceCode != "device-code" || code.UserCode != "USER-CODE" || code.Interval != 1 {
+		t.Fatalf("unexpected device code: %#v", code)
+	}
+}
+
+func TestCopilotPollDeviceToken(t *testing.T) {
+	polls := 0
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		polls++
+		if r.Method != http.MethodPost {
+			t.Fatalf("expected POST, got %s", r.Method)
+		}
+		if err := r.ParseForm(); err != nil {
+			t.Fatalf("ParseForm failed: %v", err)
+		}
+		if r.Form.Get("grant_type") != "urn:ietf:params:oauth:grant-type:device_code" {
+			t.Fatalf("unexpected grant type: %q", r.Form.Get("grant_type"))
+		}
+		if polls == 1 {
+			_ = json.NewEncoder(w).Encode(map[string]any{"error": "authorization_pending"})
+			return
+		}
+		_ = json.NewEncoder(w).Encode(map[string]any{"access_token": "github-token"})
+	}))
+	defer server.Close()
+
+	client := NewCopilotOAuthClient()
+	client.ClientID = "client-id"
+	client.TokenURL = server.URL
+	client.PollTimeout = 5 * time.Second
+	client.ClientTimeout = time.Second
+
+	token, err := client.PollDeviceToken(context.Background(), &CopilotDeviceCode{
+		DeviceCode: "device-code",
+		ExpiresIn:  10,
+		Interval:   1,
+	})
+	if err != nil {
+		t.Fatalf("PollDeviceToken failed: %v", err)
+	}
+	if token != "github-token" {
+		t.Fatalf("expected github-token, got %q", token)
+	}
+	if polls != 2 {
+		t.Fatalf("expected 2 polls, got %d", polls)
+	}
+}
+
+func TestCopilotRefreshToken(t *testing.T) {
+	expiresAt := time.Now().Add(time.Hour).Unix()
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodGet {
+			t.Fatalf("expected GET, got %s", r.Method)
+		}
+		if r.Header.Get("Authorization") != "token github-token" {
+			t.Fatalf("unexpected authorization header: %q", r.Header.Get("Authorization"))
+		}
+		if r.Header.Get("User-Agent") != "kit" {
+			t.Fatalf("unexpected user agent: %q", r.Header.Get("User-Agent"))
+		}
+		_ = json.NewEncoder(w).Encode(map[string]any{
+			"token":      "copilot-token",
+			"expires_at": expiresAt,
+		})
+	}))
+	defer server.Close()
+
+	client := NewCopilotOAuthClient()
+	client.CopilotURL = server.URL
+
+	creds, err := client.RefreshCopilotToken(context.Background(), "github-token")
+	if err != nil {
+		t.Fatalf("RefreshCopilotToken failed: %v", err)
+	}
+	if creds.GitHubToken != "github-token" || creds.CopilotAccessToken != "copilot-token" {
+		t.Fatalf("unexpected credentials: %#v", creds)
+	}
+	if creds.ExpiresAt != expiresAt {
+		t.Fatalf("expected expires_at %d, got %d", expiresAt, creds.ExpiresAt)
+	}
+}

internal/compaction/compaction.go

@@ -428,6 +428,10 @@ type PreviousCompaction struct {
 	ModifiedFiles []string
 }
 
+// StreamCallback is called for each chunk of text during streaming compaction.
+// Return a non-nil error to cancel the stream.
+type StreamCallback func(delta string) error
+
 // Compact summarises older messages using the LLM, returning the compaction
 // result and a new message slice (summary message + preserved recent
 // messages).
@@ -442,6 +446,8 @@ type PreviousCompaction struct {
 //
 // prev carries file tracking from a previous compaction for cumulative
 // tracking. Pass nil if there is no prior compaction.
+// onChunk is an optional callback for streaming summary text. Pass nil for
+// non-streaming compaction.
 func Compact(
 	ctx context.Context,
 	model fantasy.LanguageModel,
@@ -449,6 +455,7 @@ func Compact(
 	opts CompactionOptions,
 	customInstructions string,
 	prev *PreviousCompaction,
+	onChunk StreamCallback,
 ) (*CompactionResult, []fantasy.Message, error) {
 	opts.defaults()
 
@@ -487,9 +494,9 @@ func Compact(
 	var err error
 
 	if IsSplitTurn(messages, cutPoint) {
-		summaryText, err = compactSplitTurn(ctx, model, oldMessages, messages, cutPoint, opts, customInstructions)
+		summaryText, err = compactSplitTurn(ctx, model, oldMessages, messages, cutPoint, opts, customInstructions, onChunk)
 	} else {
-		summaryText, err = compactNormal(ctx, model, oldMessages, opts, customInstructions)
+		summaryText, err = compactNormal(ctx, model, oldMessages, opts, customInstructions, onChunk)
 	}
 	if err != nil {
 		return nil, nil, err
@@ -527,15 +534,17 @@ func Compact(
 }
 
 // compactNormal generates a summary for a clean turn-boundary cut.
+// If onChunk is provided, text deltas are streamed to it.
 func compactNormal(
 	ctx context.Context,
 	model fantasy.LanguageModel,
 	oldMessages []fantasy.Message,
 	opts CompactionOptions,
 	customInstructions string,
+	onChunk StreamCallback,
 ) (string, error) {
 	conversationText := serializeMessages(oldMessages)
-	return generateSummary(ctx, model, conversationText, opts, customInstructions)
+	return generateSummary(ctx, model, conversationText, opts, customInstructions, onChunk)
 }
 
 // compactSplitTurn handles the case where the cut point lands mid-turn.
@@ -546,6 +555,7 @@ func compactNormal(
 //
 // The merged result preserves context from both the older history and the
 // beginning of the current long turn.
+// If onChunk is provided, both summaries and the separator are streamed.
 func compactSplitTurn(
 	ctx context.Context,
 	model fantasy.LanguageModel,
@@ -554,6 +564,7 @@ func compactSplitTurn(
 	cutPoint int,
 	opts CompactionOptions,
 	customInstructions string,
+	onChunk StreamCallback,
 ) (string, error) {
 	// Find where the split turn starts.
 	turnStart := findTurnStart(allMessages, cutPoint)
@@ -573,12 +584,19 @@ func compactSplitTurn(
 	// Generate history summary if there are complete turns before the split.
 	if len(historyMessages) >= 2 {
 		historySummary, err = generateSummary(ctx, model,
-			serializeMessages(historyMessages), opts, "")
+			serializeMessages(historyMessages), opts, "", onChunk)
 		if err != nil {
 			return "", fmt.Errorf("split turn history summary failed: %w", err)
 		}
 	}
 
+	// Stream the separator between history and turn prefix summaries.
+	if onChunk != nil && historySummary != "" {
+		if err := onChunk("\n\n---\n\n## Current Turn (in progress)\n\n"); err != nil {
+			return "", fmt.Errorf("streaming separator failed: %w", err)
+		}
+	}
+
 	// Generate turn prefix summary.
 	turnPrefixText := serializeMessages(turnPrefixMessages)
 	turnPrefixPrompt := "The messages above are the BEGINNING of a long turn that was split. " +
@@ -588,16 +606,10 @@ func compactSplitTurn(
 		turnPrefixPrompt += "\n\nAdditional instructions: " + customInstructions
 	}
 
-	summaryAgent := fantasy.NewAgent(model,
-		fantasy.WithSystemPrompt(defaultSystemPrompt),
-	)
-	result, err := summaryAgent.Generate(ctx, fantasy.AgentCall{
-		Prompt: turnPrefixText + "\n\n" + turnPrefixPrompt,
-	})
+	turnPrefixSummary, err := generateSummary(ctx, model, turnPrefixText, opts, turnPrefixPrompt, onChunk)
 	if err != nil {
 		return "", fmt.Errorf("split turn prefix summary failed: %w", err)
 	}
-	turnPrefixSummary := result.Response.Content.Text()
 
 	// Merge the two summaries.
 	if historySummary != "" && turnPrefixSummary != "" {
@@ -610,12 +622,14 @@ func compactSplitTurn(
 }
 
 // generateSummary calls the LLM to produce a structured summary.
+// If onChunk is provided, the summary is streamed using Agent.Stream().
 func generateSummary(
 	ctx context.Context,
 	model fantasy.LanguageModel,
 	conversationText string,
 	opts CompactionOptions,
 	customInstructions string,
+	onChunk StreamCallback,
 ) (string, error) {
 	userPrompt := opts.SummaryPrompt
 	if userPrompt == "" {
@@ -628,8 +642,31 @@ func generateSummary(
 	summaryAgent := fantasy.NewAgent(model,
 		fantasy.WithSystemPrompt(defaultSystemPrompt),
 	)
+
+	prompt := conversationText + "\n\n" + userPrompt
+
+	// Use streaming if onChunk is provided.
+	if onChunk != nil {
+		var fullText strings.Builder
+		_, err := summaryAgent.Stream(ctx, fantasy.AgentStreamCall{
+			Prompt: prompt,
+			OnTextDelta: func(_, delta string) error {
+				if delta != "" {
+					fullText.WriteString(delta)
+					return onChunk(delta)
+				}
+				return nil
+			},
+		})
+		if err != nil {
+			return "", fmt.Errorf("compaction summarisation (streaming) failed: %w", err)
+		}
+		return fullText.String(), nil
+	}
+
+	// Non-streaming path.
 	result, err := summaryAgent.Generate(ctx, fantasy.AgentCall{
-		Prompt: conversationText + "\n\n" + userPrompt,
+		Prompt: prompt,
 	})
 	if err != nil {
 		return "", fmt.Errorf("compaction summarisation failed: %w", err)

internal/compaction/compaction_test.go

@@ -243,7 +243,7 @@ func TestCompact_TooFewMessages(t *testing.T) {
 		makeTextMessageN(fantasy.MessageRoleUser, 400),
 	}
 
-	result, newMsgs, err := Compact(context.TODO(), nil, msgs, CompactionOptions{}, "", nil)
+	result, newMsgs, err := Compact(context.TODO(), nil, msgs, CompactionOptions{}, "", nil, nil)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
@@ -262,7 +262,7 @@ func TestCompact_WithinBudget(t *testing.T) {
 		makeTextMessageN(fantasy.MessageRoleAssistant, 400),
 	}
 
-	result, newMsgs, err := Compact(context.TODO(), nil, msgs, CompactionOptions{}, "", nil)
+	result, newMsgs, err := Compact(context.TODO(), nil, msgs, CompactionOptions{}, "", nil, nil)
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}

internal/config/config.go

@@ -22,6 +22,45 @@ type MCPServerConfig struct {
 	AllowedTools  []string          `json:"allowedTools,omitempty" yaml:"allowedTools,omitempty"`
 	ExcludedTools []string          `json:"excludedTools,omitempty" yaml:"excludedTools,omitempty"`
 
+	// OAuth configuration for remote servers that don't support dynamic
+	// client registration (e.g. GitHub). When OAuthClientID is set, it is
+	// passed directly to the transport's OAuthConfig instead of relying on
+	// dynamic registration.
+	OAuthClientID     string   `json:"oauthClientId,omitempty" yaml:"oauthClientId,omitempty"`
+	OAuthClientSecret string   `json:"oauthClientSecret,omitempty" yaml:"oauthClientSecret,omitempty"`
+	OAuthScopes       []string `json:"oauthScopes,omitempty" yaml:"oauthScopes,omitempty"`
+
+	// NoOAuth disables OAuth transport configuration for this server, even
+	// when the connection pool has an auth handler. Use this for public MCP
+	// servers (e.g. PubMed) that don't require authentication. Without this
+	// flag, the pool would attach OAuth transport to every remote server,
+	// causing proactive dynamic-client-registration attempts that fail on
+	// servers that don't support it.
+	NoOAuth bool `json:"noOAuth,omitempty" yaml:"noOAuth,omitempty"`
+
+	// TasksMode controls when this server's tools/call requests are augmented
+	// with MCP task metadata (turning a synchronous call into an asynchronous,
+	// pollable job — see https://modelcontextprotocol.io/specification/2025-11-25/basic/utilities/tasks).
+	//
+	// Valid values:
+	//   - "" or "auto": (default) augment requests with task metadata only
+	//     when the server advertises tasks/toolCalls capability during initialize.
+	//   - "never":      never augment — every tool call is synchronous, regardless
+	//     of server capability.
+	//   - "always":     always augment, even when the server didn't advertise
+	//     task support. The server may still respond synchronously; this just
+	//     opts in unconditionally on the client side.
+	//
+	// In all modes, when the server returns a CreateTaskResult the client polls
+	// tasks/get / tasks/result until the task reaches a terminal state.
+	TasksMode string `json:"tasksMode,omitempty" yaml:"tasksMode,omitempty"`
+
+	// InProcessServer holds a live *server.MCPServer for in-process transport.
+	// When set (and Type is "inprocess"), the connection pool creates an
+	// in-process client instead of spawning a subprocess or making HTTP calls.
+	// This field is never serialized — it is only used programmatically via the SDK.
+	InProcessServer any `json:"-" yaml:"-"`
+
 	// Legacy fields for backward compatibility
 	Transport string         `json:"transport,omitempty"`
 	Args      []string       `json:"args,omitempty"`
@@ -35,13 +74,18 @@ type MCPServerConfig struct {
 func (s *MCPServerConfig) UnmarshalJSON(data []byte) error {
 	// First try to unmarshal as the new format
 	type newFormat struct {
-		Type          string            `json:"type"`
-		Command       []string          `json:"command,omitempty"`
-		Environment   map[string]string `json:"environment,omitempty"`
-		URL           string            `json:"url,omitempty"`
-		Headers       []string          `json:"headers,omitempty"`
-		AllowedTools  []string          `json:"allowedTools,omitempty" yaml:"allowedTools,omitempty"`
-		ExcludedTools []string          `json:"excludedTools,omitempty" yaml:"excludedTools,omitempty"`
+		Type              string            `json:"type"`
+		Command           []string          `json:"command,omitempty"`
+		Environment       map[string]string `json:"environment,omitempty"`
+		URL               string            `json:"url,omitempty"`
+		Headers           []string          `json:"headers,omitempty"`
+		AllowedTools      []string          `json:"allowedTools,omitempty" yaml:"allowedTools,omitempty"`
+		ExcludedTools     []string          `json:"excludedTools,omitempty" yaml:"excludedTools,omitempty"`
+		OAuthClientID     string            `json:"oauthClientId,omitempty" yaml:"oauthClientId,omitempty"`
+		OAuthClientSecret string            `json:"oauthClientSecret,omitempty" yaml:"oauthClientSecret,omitempty"`
+		OAuthScopes       []string          `json:"oauthScopes,omitempty" yaml:"oauthScopes,omitempty"`
+		NoOAuth           bool              `json:"noOAuth,omitempty" yaml:"noOAuth,omitempty"`
+		TasksMode         string            `json:"tasksMode,omitempty" yaml:"tasksMode,omitempty"`
 	}
 
 	// Also try legacy format
@@ -54,6 +98,7 @@ func (s *MCPServerConfig) UnmarshalJSON(data []byte) error {
 		Headers       []string       `json:"headers,omitempty"`
 		AllowedTools  []string       `json:"allowedTools,omitempty" yaml:"allowedTools,omitempty"`
 		ExcludedTools []string       `json:"excludedTools,omitempty" yaml:"excludedTools,omitempty"`
+		TasksMode     string         `json:"tasksMode,omitempty" yaml:"tasksMode,omitempty"`
 	}
 
 	// Try new format first
@@ -66,6 +111,11 @@ func (s *MCPServerConfig) UnmarshalJSON(data []byte) error {
 		s.Headers = newConfig.Headers
 		s.AllowedTools = newConfig.AllowedTools
 		s.ExcludedTools = newConfig.ExcludedTools
+		s.OAuthClientID = newConfig.OAuthClientID
+		s.OAuthClientSecret = newConfig.OAuthClientSecret
+		s.OAuthScopes = newConfig.OAuthScopes
+		s.NoOAuth = newConfig.NoOAuth
+		s.TasksMode = newConfig.TasksMode
 		return nil
 	}
 
@@ -86,6 +136,7 @@ func (s *MCPServerConfig) UnmarshalJSON(data []byte) error {
 	s.Headers = legacyConfig.Headers
 	s.AllowedTools = legacyConfig.AllowedTools
 	s.ExcludedTools = legacyConfig.ExcludedTools
+	s.TasksMode = legacyConfig.TasksMode
 
 	// Infer type from legacy format for better compatibility
 	// Only set Type when it doesn't change existing transport behavior
@@ -157,11 +208,28 @@ type Theme struct {
 	Markdown MarkdownThemeConfig `json:"markdown,omitzero" yaml:"markdown,omitempty"`
 }
 
+// GenerationParams defines generation parameter defaults that can be attached
+// to individual models. These act as model-level defaults — CLI flags and
+// global config values take precedence when explicitly set.
+type GenerationParams struct {
+	MaxTokens        *int     `json:"maxTokens,omitempty" yaml:"maxTokens,omitempty"`
+	Temperature      *float32 `json:"temperature,omitempty" yaml:"temperature,omitempty"`
+	TopP             *float32 `json:"topP,omitempty" yaml:"topP,omitempty"`
+	TopK             *int32   `json:"topK,omitempty" yaml:"topK,omitempty"`
+	FrequencyPenalty *float32 `json:"frequencyPenalty,omitempty" yaml:"frequencyPenalty,omitempty"`
+	PresencePenalty  *float32 `json:"presencePenalty,omitempty" yaml:"presencePenalty,omitempty"`
+	StopSequences    []string `json:"stopSequences,omitempty" yaml:"stopSequences,omitempty"`
+	ThinkingLevel    string   `json:"thinkingLevel,omitempty" yaml:"thinkingLevel,omitempty"`
+	SystemPrompt     string   `json:"systemPrompt,omitempty" yaml:"systemPrompt,omitempty"`
+}
+
 // CustomModelConfig defines a custom model that can be used with custom/custom
 // or other custom/ prefixed models. These models are loaded from the config file
 // and merged into the custom provider in the model registry.
 type CustomModelConfig struct {
 	Name        string      `json:"name" yaml:"name"`
+	BaseURL     string      `json:"baseUrl,omitempty" yaml:"baseUrl,omitempty"`
+	APIKey      string      `json:"apiKey,omitempty" yaml:"apiKey,omitempty"`
 	Family      string      `json:"family,omitempty" yaml:"family,omitempty"`
 	Attachment  bool        `json:"attachment,omitempty" yaml:"attachment,omitempty"`
 	Reasoning   bool        `json:"reasoning,omitempty" yaml:"reasoning,omitempty"`
@@ -169,6 +237,11 @@ type CustomModelConfig struct {
 	Knowledge   string      `json:"knowledge,omitempty" yaml:"knowledge,omitempty"`
 	Cost        CostConfig  `json:"cost" yaml:"cost"`
 	Limit       LimitConfig `json:"limit" yaml:"limit"`
+
+	// Generation parameter defaults for this model.
+	// These are applied when the user hasn't explicitly set the corresponding
+	// CLI flag or global config value.
+	Params GenerationParams `json:"params,omitzero" yaml:"params,omitempty"`
 }
 
 // CostConfig defines the pricing for a custom model.
@@ -191,18 +264,19 @@ type Config struct {
 	Model          string                     `json:"model,omitempty" yaml:"model,omitempty"`
 	MaxSteps       int                        `json:"max-steps,omitempty" yaml:"max-steps,omitempty"`
 	Debug          bool                       `json:"debug,omitempty" yaml:"debug,omitempty"`
-	Compact        bool                       `json:"compact,omitempty" yaml:"compact,omitempty"`
 	SystemPrompt   string                     `json:"system-prompt,omitempty" yaml:"system-prompt,omitempty"`
 	ProviderAPIKey string                     `json:"provider-api-key,omitempty" yaml:"provider-api-key,omitempty"`
 	ProviderURL    string                     `json:"provider-url,omitempty" yaml:"provider-url,omitempty"`
 	Stream         *bool                      `json:"stream,omitempty" yaml:"stream,omitempty"`
 	Theme          any                        `json:"theme" yaml:"theme"`
 	// Model generation parameters
-	MaxTokens     int      `json:"max-tokens,omitempty" yaml:"max-tokens,omitempty"`
-	Temperature   *float32 `json:"temperature,omitempty" yaml:"temperature,omitempty"`
-	TopP          *float32 `json:"top-p,omitempty" yaml:"top-p,omitempty"`
-	TopK          *int32   `json:"top-k,omitempty" yaml:"top-k,omitempty"`
-	StopSequences []string `json:"stop-sequences,omitempty" yaml:"stop-sequences,omitempty"`
+	MaxTokens        int      `json:"max-tokens,omitempty" yaml:"max-tokens,omitempty"`
+	Temperature      *float32 `json:"temperature,omitempty" yaml:"temperature,omitempty"`
+	TopP             *float32 `json:"top-p,omitempty" yaml:"top-p,omitempty"`
+	TopK             *int32   `json:"top-k,omitempty" yaml:"top-k,omitempty"`
+	FrequencyPenalty *float32 `json:"frequency-penalty,omitempty" yaml:"frequency-penalty,omitempty"`
+	PresencePenalty  *float32 `json:"presence-penalty,omitempty" yaml:"presence-penalty,omitempty"`
+	StopSequences    []string `json:"stop-sequences,omitempty" yaml:"stop-sequences,omitempty"`
 
 	// Thinking / extended reasoning
 	ThinkingLevel string `json:"thinking-level,omitempty" yaml:"thinking-level,omitempty"`
@@ -216,6 +290,12 @@ type Config struct {
 
 	// Custom model definitions (under custom/ provider)
 	CustomModels map[string]CustomModelConfig `json:"customModels,omitempty" yaml:"customModels,omitempty"`
+
+	// Per-model generation parameter overrides. Keys are "provider/model" strings
+	// (e.g. "anthropic/claude-sonnet-4-5-20250929", "openai/gpt-4o"). These
+	// settings act as model-level defaults — CLI flags and global config values
+	// take precedence when explicitly set.
+	ModelSettings map[string]GenerationParams `json:"modelSettings,omitempty" yaml:"modelSettings,omitempty"`
 }
 
 // GetTransportType returns the transport type for the server config, mapping
@@ -234,11 +314,18 @@ func (s *MCPServerConfig) GetTransportType() string {
 			return "stdio"
 		case "remote":
 			return "streamable"
+		case "inprocess":
+			return "inprocess"
 		default:
 			return s.Type
 		}
 	}
 
+	// Programmatic in-process server detection.
+	if s.InProcessServer != nil {
+		return "inprocess"
+	}
+
 	// Backward compatibility: infer transport type
 	if len(s.Command) > 0 {
 		return "stdio"
@@ -258,6 +345,17 @@ func (c *Config) Validate() error {
 			return fmt.Errorf("server %s: allowedTools and excludedTools are mutually exclusive", serverName)
 		}
 
+		// Reject unknown tasksMode values up front so a typo (e.g. "alwasy")
+		// fails loud here instead of being silently downgraded to "auto" by
+		// the runtime parser. Comparison is case-insensitive to match
+		// tools.ParseTaskMode.
+		switch strings.ToLower(strings.TrimSpace(serverConfig.TasksMode)) {
+		case "", "auto", "never", "always":
+			// ok
+		default:
+			return fmt.Errorf("server %s: invalid tasksMode %q (expected one of: auto, never, always)", serverName, serverConfig.TasksMode)
+		}
+
 		transport := serverConfig.GetTransportType()
 		switch transport {
 		case "stdio":
@@ -269,8 +367,12 @@ func (c *Config) Validate() error {
 			if serverConfig.URL == "" {
 				return fmt.Errorf("server %s: url is required for %s transport", serverName, transport)
 			}
+		case "inprocess":
+			if serverConfig.InProcessServer == nil {
+				return fmt.Errorf("server %s: InProcessServer is required for inprocess transport", serverName)
+			}
 		default:
-			return fmt.Errorf("server %s: unsupported transport type '%s'. Supported types: stdio, sse, streamable", serverName, transport)
+			return fmt.Errorf("server %s: unsupported transport type '%s'. Supported types: stdio, sse, streamable, inprocess", serverName, transport)
 		}
 	}
 	return nil
@@ -364,16 +466,61 @@ mcpServers:
 # debug: false                                 # Enable debug logging
 # system-prompt: "/path/to/system-prompt.txt" # System prompt text file
 
-# Model generation parameters (all optional)
+# Model generation parameters (all optional, apply globally to all models)
 # max-tokens: 4096                             # Maximum tokens in response
 # temperature: 0.7                             # Randomness (0.0-1.0)
 # top-p: 0.95                                  # Nucleus sampling (0.0-1.0)
 # top-k: 40                                    # Top K sampling
+# frequency-penalty: 0.0                        # Penalize frequent tokens (0.0-2.0)
+# presence-penalty: 0.0                         # Penalize present tokens (0.0-2.0)
 # stop-sequences: ["Human:", "Assistant:"]     # Custom stop sequences
 
+# Per-model generation parameter overrides (apply to specific models)
+# These act as model-level defaults — CLI flags and global settings above take precedence.
+# Keys are "provider/model" strings matching the model you use.
+# modelSettings:
+#   anthropic/claude-sonnet-4-5-20250929:
+#     temperature: 0.3
+#     maxTokens: 8192
+#   openai/gpt-4o:
+#     temperature: 0.7
+#     topP: 0.95
+#     topK: 40
+#     frequencyPenalty: 0.1
+#     presencePenalty: 0.1
+#   anthropic/claude-opus-4-6:
+#     thinkingLevel: "high"
+#     maxTokens: 16384
+#     systemPrompt: "You are a deep reasoning assistant."  # or a file path
+
+# Skills configuration (all optional)
+# no-skills: false                          # Set to true to disable all skill loading
+# skill:                                    # Explicit skill files/dirs (disables auto-discovery)
+#   - "/path/to/skill.md"
+# skills-dir: "/path/to/skills"            # Override project-local directory for auto-discovery
+
 # API Configuration (can also use environment variables)
 # provider-api-key: "your-api-key"         # API key for OpenAI, Anthropic, or Google
 # provider-url: "https://api.openai.com/v1" # Base URL for OpenAI, Anthropic, or Ollama
+
+# Custom model definitions (under custom/ provider)
+# customModels:
+#   my-local-llama:
+#     name: "Local Llama 3"
+#     baseUrl: "http://localhost:8080/v1"
+#     family: "llama"
+#     temperature: true
+#     cost:
+#       input: 0.0
+#       output: 0.0
+#     limit:
+#       context: 131072
+#       output: 8192
+#     params:                              # Generation parameter defaults for this model
+#       temperature: 0.8
+#       topP: 0.95
+#       topK: 40
+#       systemPrompt: "You are a helpful local assistant."
 `
 
 	_, err = file.WriteString(content)
@@ -403,10 +550,9 @@ func FilepathOr[T any](key string, value *T) error {
 				if err != nil {
 					return err
 				}
-				filepath.Join(home, absPath[2:])
+				absPath = filepath.Join(home, absPath[2:])
 			}
 			if !filepath.IsAbs(absPath) {
-				// base := GetConfigPath()
 				base := configPath
 				if base == "" {
 					fmt.Fprintf(os.Stderr, "unable to build relative path to config.")

internal/config/config_test.go

@@ -6,6 +6,8 @@ import (
 	"path/filepath"
 	"strings"
 	"testing"
+
+	"gopkg.in/yaml.v3"
 )
 
 func TestMCPServerConfig_NewFormat(t *testing.T) {
@@ -203,6 +205,9 @@ func TestEnsureConfigExists(t *testing.T) {
 		"type: \"local\"",
 		"type: \"remote\"",
 		"Core tools",
+		"# Skills configuration",
+		"no-skills:",
+		"skills-dir:",
 	}
 
 	for _, expected := range expectedSections {
@@ -542,3 +547,175 @@ func TestEnsureConfigExistsWhenFileExists(t *testing.T) {
 		t.Error("Existing config file was modified when it shouldn't have been")
 	}
 }
+
+func TestMCPServerConfig_OAuthFields_JSON(t *testing.T) {
+	jsonData := `{
+		"type": "remote",
+		"url": "https://api.githubcopilot.com/mcp/",
+		"oauthClientId": "Ov23liXXXXXXXXXXXXXX",
+		"oauthClientSecret": "secret123",
+		"oauthScopes": ["read:user", "repo"]
+	}`
+
+	var cfg MCPServerConfig
+	err := json.Unmarshal([]byte(jsonData), &cfg)
+	if err != nil {
+		t.Fatalf("Failed to unmarshal: %v", err)
+	}
+
+	if cfg.Type != "remote" {
+		t.Errorf("Expected type 'remote', got %q", cfg.Type)
+	}
+	if cfg.URL != "https://api.githubcopilot.com/mcp/" {
+		t.Errorf("Expected URL, got %q", cfg.URL)
+	}
+	if cfg.OAuthClientID != "Ov23liXXXXXXXXXXXXXX" {
+		t.Errorf("Expected OAuthClientID 'Ov23liXXXXXXXXXXXXXX', got %q", cfg.OAuthClientID)
+	}
+	if cfg.OAuthClientSecret != "secret123" {
+		t.Errorf("Expected OAuthClientSecret 'secret123', got %q", cfg.OAuthClientSecret)
+	}
+	if len(cfg.OAuthScopes) != 2 || cfg.OAuthScopes[0] != "read:user" || cfg.OAuthScopes[1] != "repo" {
+		t.Errorf("Expected OAuthScopes [read:user, repo], got %v", cfg.OAuthScopes)
+	}
+}
+
+func TestMCPServerConfig_OAuthFields_YAML(t *testing.T) {
+	yamlData := `
+type: remote
+url: https://api.githubcopilot.com/mcp/
+oauthClientId: "Ov23liXXXXXXXXXXXXXX"
+oauthScopes:
+  - read:user
+  - repo
+`
+
+	var cfg MCPServerConfig
+	err := yaml.Unmarshal([]byte(yamlData), &cfg)
+	if err != nil {
+		t.Fatalf("Failed to unmarshal YAML: %v", err)
+	}
+
+	if cfg.Type != "remote" {
+		t.Errorf("Expected type 'remote', got %q", cfg.Type)
+	}
+	if cfg.OAuthClientID != "Ov23liXXXXXXXXXXXXXX" {
+		t.Errorf("Expected OAuthClientID 'Ov23liXXXXXXXXXXXXXX', got %q", cfg.OAuthClientID)
+	}
+	if len(cfg.OAuthScopes) != 2 || cfg.OAuthScopes[0] != "read:user" || cfg.OAuthScopes[1] != "repo" {
+		t.Errorf("Expected OAuthScopes [read:user, repo], got %v", cfg.OAuthScopes)
+	}
+}
+
+func TestMCPServerConfig_OAuthFields_Omitted(t *testing.T) {
+	// Verify that omitting OAuth fields still works (backward compat).
+	jsonData := `{
+		"type": "remote",
+		"url": "https://example.com/mcp"
+	}`
+
+	var cfg MCPServerConfig
+	err := json.Unmarshal([]byte(jsonData), &cfg)
+	if err != nil {
+		t.Fatalf("Failed to unmarshal: %v", err)
+	}
+
+	if cfg.OAuthClientID != "" {
+		t.Errorf("Expected empty OAuthClientID, got %q", cfg.OAuthClientID)
+	}
+	if cfg.OAuthClientSecret != "" {
+		t.Errorf("Expected empty OAuthClientSecret, got %q", cfg.OAuthClientSecret)
+	}
+	if len(cfg.OAuthScopes) != 0 {
+		t.Errorf("Expected empty OAuthScopes, got %v", cfg.OAuthScopes)
+	}
+}
+
+func TestMCPServerConfig_TasksMode_NewFormat(t *testing.T) {
+	jsonData := `{
+		"type": "remote",
+		"url": "https://my-mcp-server.com",
+		"tasksMode": "always"
+	}`
+	var cfg MCPServerConfig
+	if err := json.Unmarshal([]byte(jsonData), &cfg); err != nil {
+		t.Fatalf("Failed to unmarshal: %v", err)
+	}
+	if cfg.TasksMode != "always" {
+		t.Errorf("expected TasksMode 'always', got %q", cfg.TasksMode)
+	}
+}
+
+func TestMCPServerConfig_TasksMode_LegacyFormat(t *testing.T) {
+	// tasksMode also recognised in the legacy unmarshal path so users on
+	// the older command/args shape can opt in without migrating.
+	jsonData := `{
+		"command": "npx",
+		"args": ["@modelcontextprotocol/server-filesystem", "/path"],
+		"tasksMode": "never"
+	}`
+	var cfg MCPServerConfig
+	if err := json.Unmarshal([]byte(jsonData), &cfg); err != nil {
+		t.Fatalf("Failed to unmarshal: %v", err)
+	}
+	if cfg.TasksMode != "never" {
+		t.Errorf("expected TasksMode 'never', got %q", cfg.TasksMode)
+	}
+}
+
+func TestMCPServerConfig_TasksMode_DefaultEmpty(t *testing.T) {
+	// When tasksMode is not set the field stays empty, which downstream
+	// resolves to "auto" via tools.ParseTaskMode.
+	jsonData := `{"type":"remote","url":"https://x.example"}`
+	var cfg MCPServerConfig
+	if err := json.Unmarshal([]byte(jsonData), &cfg); err != nil {
+		t.Fatalf("Failed to unmarshal: %v", err)
+	}
+	if cfg.TasksMode != "" {
+		t.Errorf("expected default TasksMode to be empty, got %q", cfg.TasksMode)
+	}
+}
+
+func TestConfig_Validate_TasksMode(t *testing.T) {
+	t.Run("empty is valid", func(t *testing.T) {
+		cfg := &Config{
+			MCPServers: map[string]MCPServerConfig{
+				"a": {Type: "remote", URL: "https://x.example"},
+			},
+		}
+		if err := cfg.Validate(); err != nil {
+			t.Errorf("empty TasksMode should validate, got %v", err)
+		}
+	})
+
+	t.Run("known values are valid", func(t *testing.T) {
+		for _, mode := range []string{"auto", "never", "always", "AUTO", " always "} {
+			cfg := &Config{
+				MCPServers: map[string]MCPServerConfig{
+					"a": {Type: "remote", URL: "https://x.example", TasksMode: mode},
+				},
+			}
+			if err := cfg.Validate(); err != nil {
+				t.Errorf("TasksMode=%q should validate, got %v", mode, err)
+			}
+		}
+	})
+
+	t.Run("typo is rejected with a clear error", func(t *testing.T) {
+		cfg := &Config{
+			MCPServers: map[string]MCPServerConfig{
+				"buildbot": {Type: "remote", URL: "https://x.example", TasksMode: "alwasy"},
+			},
+		}
+		err := cfg.Validate()
+		if err == nil {
+			t.Fatal("expected validation error for invalid TasksMode")
+		}
+		// Error must mention the server name AND the bad value so the
+		// user knows where to look.
+		msg := err.Error()
+		if !strings.Contains(msg, "buildbot") || !strings.Contains(msg, `"alwasy"`) {
+			t.Errorf("error %q should mention both server name and bad value", msg)
+		}
+	})
+}

internal/config/merger.go

@@ -7,32 +7,48 @@ import (
 	"github.com/spf13/viper"
 )
 
-// LoadAndValidateConfig loads configuration from viper, fixes environment variable
-// casing issues, and validates the configuration. Returns an error if loading or
-// validation fails.
+// LoadAndValidateConfig loads configuration from the process-global viper
+// store, fixes environment variable casing issues, and validates the
+// configuration. Returns an error if loading or validation fails.
+//
+// This is a convenience wrapper around [LoadAndValidateConfigFrom] using the
+// shared global store; it is retained for the CLI and other callers that rely
+// on viper's process-global state.
 func LoadAndValidateConfig() (*Config, error) {
+	return LoadAndValidateConfigFrom(viper.GetViper())
+}
+
+// LoadAndValidateConfigFrom loads configuration from the supplied per-instance
+// store, fixes environment variable casing issues, and validates the
+// configuration. When v is nil, the process-global store is used. Threading an
+// explicit store lets each Kit instance own an isolated configuration without
+// clobbering other instances in the same process.
+func LoadAndValidateConfigFrom(v *viper.Viper) (*Config, error) {
+	if v == nil {
+		v = viper.GetViper()
+	}
 	config := &Config{
 		MCPServers: make(map[string]MCPServerConfig),
 	}
-	if err := viper.Unmarshal(config); err != nil {
-		return nil, fmt.Errorf("failed to unmarshal config: %v", err)
+	if err := v.Unmarshal(config); err != nil {
+		return nil, fmt.Errorf("failed to unmarshal config: %w", err)
 	}
 
 	// Fix environment variable case sensitivity issue
 	// Viper lowercases all keys, but we need to preserve the original case for environment variables
-	fixEnvironmentCase(config)
+	fixEnvironmentCase(v, config)
 
 	if err := config.Validate(); err != nil {
-		return nil, fmt.Errorf("invalid config: %v", err)
+		return nil, fmt.Errorf("invalid config: %w", err)
 	}
 
 	return config, nil
 }
 
 // fixEnvironmentCase fixes the case of environment variable keys that were lowercased by Viper
-func fixEnvironmentCase(config *Config) {
+func fixEnvironmentCase(v *viper.Viper, config *Config) {
 	// Get the raw config data from viper
-	rawConfig := viper.AllSettings()
+	rawConfig := v.AllSettings()
 
 	// Check if we have mcpServers in the raw config
 	if mcpServersRaw, ok := rawConfig["mcpservers"]; ok {

internal/config/substitution.go

@@ -56,9 +56,3 @@ func (e *EnvSubstituter) SubstituteEnvVars(content string) (string, error) {
 
 	return result, nil
 }
-
-// HasEnvVars checks if content contains environment variable patterns (${env://...}).
-// This is useful for determining if substitution is needed before processing.
-func HasEnvVars(content string) bool {
-	return envVarPattern.MatchString(content)
-}

internal/config/substitution_test.go

@@ -187,41 +187,3 @@ func TestEnvSubstituter_SubstituteEnvVars(t *testing.T) {
 		})
 	}
 }
-
-func TestHasEnvVars(t *testing.T) {
-	tests := []struct {
-		name     string
-		content  string
-		expected bool
-	}{
-		{
-			name:     "has env vars",
-			content:  `{"token": "${env://GITHUB_TOKEN}"}`,
-			expected: true,
-		},
-		{
-			name:     "has env vars with default",
-			content:  `{"debug": "${env://DEBUG:-false}"}`,
-			expected: true,
-		},
-		{
-			name:     "no env vars",
-			content:  `{"name": "${username}", "normal": "value"}`,
-			expected: false,
-		},
-		{
-			name:     "empty content",
-			content:  "",
-			expected: false,
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			result := HasEnvVars(tt.content)
-			if result != tt.expected {
-				t.Errorf("Expected %v, got %v", tt.expected, result)
-			}
-		})
-	}
-}

internal/core/bash.go

@@ -7,6 +7,7 @@ import (
 	"io"
 	"os"
 	"os/exec"
+	"regexp"
 	"strings"
 	"sync"
 	"time"
@@ -18,10 +19,18 @@ import (
 // It receives tool call ID, tool name, output chunk, and whether it's stderr.
 type ToolOutputCallback func(toolCallID, toolName, chunk string, isStderr bool)
 
+// PasswordPromptCallback is the signature for password prompts.
+// It receives a prompt message and returns the password and whether it was cancelled.
+type PasswordPromptCallback func(prompt string) (password string, cancelled bool)
+
 // contextKey is a custom type for context keys to avoid collisions.
 type contextKey string
 
-const toolOutputCallbackKey contextKey = "toolOutputCallback"
+const (
+	toolOutputCallbackKey contextKey = "toolOutputCallback"
+	sudoPasswordKey       contextKey = "sudoPassword"
+	passwordPromptKey     contextKey = "passwordPrompt"
+)
 
 // ContextWithToolOutputCallback returns a new context with the tool output callback set.
 func ContextWithToolOutputCallback(ctx context.Context, callback ToolOutputCallback) context.Context {
@@ -36,23 +45,33 @@ func toolOutputCallbackFromContext(ctx context.Context) ToolOutputCallback {
 	return nil
 }
 
+// ContextWithPasswordPrompt returns a new context with the password prompt callback set.
+// This allows the TUI to show a modal password prompt when sudo needs a password.
+func ContextWithPasswordPrompt(ctx context.Context, callback PasswordPromptCallback) context.Context {
+	return context.WithValue(ctx, passwordPromptKey, callback)
+}
+
+// passwordPromptFromContext retrieves the password prompt callback from context.
+func passwordPromptFromContext(ctx context.Context) PasswordPromptCallback {
+	if cb, ok := ctx.Value(passwordPromptKey).(PasswordPromptCallback); ok {
+		return cb
+	}
+	return nil
+}
+
+// sudoPasswordFromContext retrieves the sudo password from context.
+func sudoPasswordFromContext(ctx context.Context) string {
+	if pw, ok := ctx.Value(sudoPasswordKey).(string); ok {
+		return pw
+	}
+	return ""
+}
+
 const defaultBashTimeout = 120 * time.Second
 const maxBashTimeout = 600 * time.Second
 
-var bannedCommands = []string{
-	"alias ", "bg ", "bind ", "builtin ",
-	"caller ", "command ", "compgen ",
-	"complete ", "compopt ", "coproc ",
-	"dirs ", "disown ", "enable ",
-	"fc ", "fg ", "hash ", "help ",
-	"history ", "jobs ", "kill ",
-	"logout ", "mapfile ", "popd ",
-	"pushd ", "readonly ", "select ",
-	"set ", "shopt ", "source ",
-	"suspend ", "times ", "trap ",
-	"type ", "typeset ", "ulimit ",
-	"umask ", "unalias ", "wait ",
-}
+// bannedCmdRe matches bash builtin commands that are not allowed for security reasons.
+var bannedCmdRe = regexp.MustCompile(`^(alias|bg|bind|builtin|caller|command|compgen|complete|compopt|coproc|dirs|disown|enable|fc|fg|hash|help|history|jobs|kill|logout|mapfile|popd|pushd|readonly|select|set|shopt|source|suspend|times|trap|type|typeset|ulimit|umask|unalias|wait)\s`)
 
 type bashArgs struct {
 	Command string  `json:"command"`
@@ -84,6 +103,57 @@ func NewBashTool(opts ...ToolOption) fantasy.AgentTool {
 	}
 }
 
+// sudoCommandRe matches sudo commands that need to be rewritten for -S mode.
+// It matches "sudo" as a word boundary, optionally preceded by environment variables.
+var sudoCommandRe = regexp.MustCompile(`(?i)(^|[&|;|]|\|\||&&)\s*(\w+=\S+\s+)?\bsudo\b`)
+
+// truncateCommand truncates a long command for display.
+func truncateCommand(cmd string, maxLen int) string {
+	if len(cmd) <= maxLen {
+		return cmd
+	}
+	return cmd[:maxLen-3] + "..."
+}
+
+// rewriteSudoForStdin rewrites sudo commands to use -S -p ” for stdin password input.
+// It transforms: sudo cmd → sudo -S -p ” cmd
+func rewriteSudoForStdin(command string) string {
+	// Find all matches and their positions
+	matches := sudoCommandRe.FindAllStringIndex(command, -1)
+	if matches == nil {
+		return command
+	}
+
+	// Build result from end to start to preserve indices
+	result := command
+	for i := len(matches) - 1; i >= 0; i-- {
+		match := matches[i]
+		start, end := match[0], match[1]
+		matchedText := result[start:end]
+
+		// Extract just the "sudo" part (after any prefix)
+		sudoIdx := strings.Index(strings.ToLower(matchedText), "sudo")
+		if sudoIdx == -1 {
+			continue
+		}
+		prefix := matchedText[:sudoIdx]
+		sudoPart := matchedText[sudoIdx:]
+
+		// Check if the text immediately after "sudo" in the result contains -S
+		afterSudo := result[end:]
+		if strings.HasPrefix(strings.TrimLeft(afterSudo, " \t"), "-S") {
+			// Already has -S flag, skip
+			continue
+		}
+
+		// Insert -S -p '' after "sudo"
+		newSudo := strings.Replace(sudoPart, "sudo", "sudo -S -p ''", 1)
+		result = result[:start] + prefix + newSudo + result[end:]
+	}
+
+	return result
+}
+
 func executeBash(ctx context.Context, call fantasy.ToolCall, workDir string) (fantasy.ToolResponse, error) {
 	var args bashArgs
 	if err := parseArgs(call.Input, &args); err != nil {
@@ -94,10 +164,8 @@ func executeBash(ctx context.Context, call fantasy.ToolCall, workDir string) (fa
 	}
 
 	// Check for banned commands
-	for _, banned := range bannedCommands {
-		if strings.HasPrefix(args.Command, banned) {
-			return fantasy.NewTextErrorResponse(fmt.Sprintf("command '%s' is not allowed", args.Command)), nil
-		}
+	if bannedCmdRe.MatchString(args.Command) {
+		return fantasy.NewTextErrorResponse(fmt.Sprintf("command '%s' is not allowed", args.Command)), nil
 	}
 
 	// Determine timeout
@@ -110,7 +178,47 @@ func executeBash(ctx context.Context, call fantasy.ToolCall, workDir string) (fa
 	cmdCtx, cancel := context.WithTimeout(ctx, timeout)
 	defer cancel()
 
-	cmd := exec.CommandContext(cmdCtx, "bash", "-c", args.Command)
+	// Check for sudo password in context or environment
+	sudoPassword := sudoPasswordFromContext(ctx)
+	if sudoPassword == "" {
+		sudoPassword = os.Getenv("SUDO_PASSWORD")
+	}
+	command := args.Command
+
+	// If command contains sudo and we don't have a password, check if sudo needs one
+	if sudoPassword == "" && sudoCommandRe.MatchString(command) {
+		// Check if sudo credentials are cached using sudo -n (non-interactive)
+		testCmd := exec.CommandContext(cmdCtx, "sudo", "-n", "true")
+		testCmd.Dir = workDir
+		if err := testCmd.Run(); err != nil {
+			// Sudo needs a password - try to prompt via callback
+			if promptCallback := passwordPromptFromContext(ctx); promptCallback != nil {
+				pw, cancelled := promptCallback("Sudo password required for: " + truncateCommand(args.Command, 60))
+				if cancelled {
+					return fantasy.NewTextErrorResponse("sudo password prompt cancelled"), nil
+				}
+				if pw == "" {
+					return fantasy.NewTextErrorResponse("no sudo password provided"), nil
+				}
+				sudoPassword = pw
+				command = rewriteSudoForStdin(command)
+			} else {
+				// No callback available - return error with helpful message
+				return fantasy.NewTextErrorResponse(
+					"This command requires sudo access. " +
+						"Please run 'sudo -v' in your terminal first to cache credentials, " +
+						"or set the SUDO_PASSWORD environment variable."), nil
+			}
+		}
+		// Credentials are cached or password was provided, proceed
+	}
+
+	// If we have a sudo password, rewrite the command to use sudo -S
+	if sudoPassword != "" && sudoCommandRe.MatchString(command) {
+		command = rewriteSudoForStdin(command)
+	}
+
+	cmd := exec.CommandContext(cmdCtx, "bash", "-c", command)
 	if workDir != "" {
 		cmd.Dir = workDir
 	}
@@ -128,44 +236,94 @@ func executeBash(ctx context.Context, call fantasy.ToolCall, workDir string) (fa
 
 	if outputCallback != nil {
 		// Streaming mode: use pipes to capture output as it arrives
-		return executeBashStreaming(cmdCtx, call, cmd, outputCallback)
+		return executeBashStreaming(cmdCtx, call, cmd, outputCallback, sudoPassword)
 	}
 
 	// Non-streaming mode: collect all output at once (original behavior)
-	return executeBashBuffered(cmdCtx, call, cmd)
+	return executeBashBuffered(cmdCtx, call, cmd, sudoPassword)
+}
+
+// setupBashPipes opens stdout/stderr pipes (plus an optional sudo stdin),
+// starts the command, and asynchronously writes the sudo password if any.
+// Returns the readers ready for the caller to consume. If setup fails,
+// errResp is non-nil and the readers must not be used; the caller should
+// return the response directly.
+func setupBashPipes(cmd *exec.Cmd, sudoPassword string) (stdout, stderr io.Reader, errResp *fantasy.ToolResponse) {
+	stdoutPipe, err := cmd.StdoutPipe()
+	if err != nil {
+		r := fantasy.NewTextErrorResponse("failed to create stdout pipe")
+		return nil, nil, &r
+	}
+	stderrPipe, err := cmd.StderrPipe()
+	if err != nil {
+		r := fantasy.NewTextErrorResponse("failed to create stderr pipe")
+		return nil, nil, &r
+	}
+
+	var stdinPipe io.WriteCloser
+	if sudoPassword != "" {
+		stdinPipe, err = cmd.StdinPipe()
+		if err != nil {
+			r := fantasy.NewTextErrorResponse("failed to create stdin pipe")
+			return nil, nil, &r
+		}
+	}
+
+	if err := cmd.Start(); err != nil {
+		r := fantasy.NewTextErrorResponse(fmt.Sprintf("failed to start command: %v", err))
+		return nil, nil, &r
+	}
+
+	if sudoPassword != "" && stdinPipe != nil {
+		go func() {
+			defer func() { _ = stdinPipe.Close() }()
+			_, _ = io.WriteString(stdinPipe, sudoPassword+"\n")
+		}()
+	}
+
+	return stdoutPipe, stderrPipe, nil
+}
+
+// interpretBashExit decodes cmd.Wait()'s error into an exit code, mapping
+// context-deadline-exceeded to a friendly "command timed out" response.
+// errResp is non-nil only when the caller should short-circuit and return
+// it directly (e.g. timeout).
+func interpretBashExit(waitErr error, cmdCtx context.Context) (exitCode int, errResp *fantasy.ToolResponse) {
+	if waitErr == nil {
+		return 0, nil
+	}
+	if exitErr, ok := waitErr.(*exec.ExitError); ok {
+		return exitErr.ExitCode(), nil
+	}
+	if cmdCtx.Err() == context.DeadlineExceeded {
+		r := fantasy.NewTextErrorResponse("command timed out")
+		return 0, &r
+	}
+	return 0, nil
 }
 
 // executeBashBuffered collects all output before returning (original behavior).
 // It uses explicit pipes (not cmd.Stdout) so that cmd.WaitDelay can forcibly
 // close them when grandchild processes hold pipe handles open after the
 // direct child exits.
-func executeBashBuffered(cmdCtx context.Context, call fantasy.ToolCall, cmd *exec.Cmd) (fantasy.ToolResponse, error) {
-	stdoutPipe, err := cmd.StdoutPipe()
-	if err != nil {
-		return fantasy.NewTextErrorResponse("failed to create stdout pipe"), nil
-	}
-	stderrPipe, err := cmd.StderrPipe()
-	if err != nil {
-		return fantasy.NewTextErrorResponse("failed to create stderr pipe"), nil
-	}
-
-	if err := cmd.Start(); err != nil {
-		return fantasy.NewTextErrorResponse(fmt.Sprintf("failed to start command: %v", err)), nil
+func executeBashBuffered(cmdCtx context.Context, _ fantasy.ToolCall, cmd *exec.Cmd, sudoPassword string) (fantasy.ToolResponse, error) {
+	stdoutPipe, stderrPipe, errResp := setupBashPipes(cmd, sudoPassword)
+	if errResp != nil {
+		return *errResp, nil
 	}
 
 	// Read pipes concurrently
 	var wg sync.WaitGroup
 	var stdout, stderr strings.Builder
-	var stdoutErr, stderrErr error
 
 	wg.Add(2)
 	go func() {
 		defer wg.Done()
-		_, stdoutErr = io.Copy(&stdout, stdoutPipe)
+		_, _ = io.Copy(&stdout, stdoutPipe)
 	}()
 	go func() {
 		defer wg.Done()
-		_, stderrErr = io.Copy(&stderr, stderrPipe)
+		_, _ = io.Copy(&stderr, stderrPipe)
 	}()
 
 	// Wait for the process to exit first. cmd.WaitDelay ensures that if
@@ -176,37 +334,19 @@ func executeBashBuffered(cmdCtx context.Context, call fantasy.ToolCall, cmd *exe
 	// Wait for pipe readers to finish draining.
 	wg.Wait()
 
-	// Ignore pipe read errors caused by WaitDelay force-closing —
-	// we still have whatever was read before the close.
-	_ = stdoutErr
-	_ = stderrErr
-
-	exitCode := 0
-	if waitErr != nil {
-		if exitErr, ok := waitErr.(*exec.ExitError); ok {
-			exitCode = exitErr.ExitCode()
-		} else if cmdCtx.Err() == context.DeadlineExceeded {
-			return fantasy.NewTextErrorResponse("command timed out"), nil
-		}
+	exitCode, errResp := interpretBashExit(waitErr, cmdCtx)
+	if errResp != nil {
+		return *errResp, nil
 	}
 
 	return buildBashResponse(stdout.String(), stderr.String(), exitCode)
 }
 
 // executeBashStreaming streams output as it arrives via the callback.
-func executeBashStreaming(cmdCtx context.Context, call fantasy.ToolCall, cmd *exec.Cmd, outputCallback ToolOutputCallback) (fantasy.ToolResponse, error) {
-	stdoutPipe, err := cmd.StdoutPipe()
-	if err != nil {
-		return fantasy.NewTextErrorResponse("failed to create stdout pipe"), nil
-	}
-	stderrPipe, err := cmd.StderrPipe()
-	if err != nil {
-		return fantasy.NewTextErrorResponse("failed to create stderr pipe"), nil
-	}
-
-	// Start command execution
-	if err := cmd.Start(); err != nil {
-		return fantasy.NewTextErrorResponse(fmt.Sprintf("failed to start command: %v", err)), nil
+func executeBashStreaming(cmdCtx context.Context, call fantasy.ToolCall, cmd *exec.Cmd, outputCallback ToolOutputCallback, sudoPassword string) (fantasy.ToolResponse, error) {
+	stdoutPipe, stderrPipe, errResp := setupBashPipes(cmd, sudoPassword)
+	if errResp != nil {
+		return *errResp, nil
 	}
 
 	// Stream stdout and stderr concurrently
@@ -243,20 +383,16 @@ func executeBashStreaming(cmdCtx context.Context, call fantasy.ToolCall, cmd *ex
 	// Wait for the process to exit. cmd.WaitDelay ensures that if pipes
 	// remain open (held by grandchild processes), they'll be forcibly closed
 	// after the grace period, which unblocks the scanners above.
-	err = cmd.Wait()
+	waitErr := cmd.Wait()
 
 	// Wait for the pipe readers to finish draining. This will complete
 	// quickly since cmd.Wait() (with WaitDelay) has already ensured
 	// the pipes are closed.
 	wg.Wait()
 
-	exitCode := 0
-	if err != nil {
-		if exitErr, ok := err.(*exec.ExitError); ok {
-			exitCode = exitErr.ExitCode()
-		} else if cmdCtx.Err() == context.DeadlineExceeded {
-			return fantasy.NewTextErrorResponse("command timed out"), nil
-		}
+	exitCode, errResp := interpretBashExit(waitErr, cmdCtx)
+	if errResp != nil {
+		return *errResp, nil
 	}
 
 	return buildBashResponse(strings.Join(stdoutChunks, "\n"), strings.Join(stderrChunks, "\n"), exitCode)

internal/core/bash_test.go

@@ -127,3 +127,72 @@ func TestBash_EmptyCommand(t *testing.T) {
 		t.Fatal("expected error for empty command")
 	}
 }
+
+func TestRewriteSudoForStdin(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{
+			name:     "simple sudo",
+			input:    "sudo apt update",
+			expected: "sudo -S -p '' apt update",
+		},
+		{
+			name:     "sudo with env var",
+			input:    "DEBIAN_FRONTEND=noninteractive sudo apt update",
+			expected: "DEBIAN_FRONTEND=noninteractive sudo -S -p '' apt update",
+		},
+		{
+			name:     "sudo in pipeline",
+			input:    "echo test | sudo tee /etc/test.conf",
+			expected: "echo test | sudo -S -p '' tee /etc/test.conf",
+		},
+		{
+			name:     "sudo after &&",
+			input:    "apt update && sudo apt upgrade",
+			expected: "apt update && sudo -S -p '' apt upgrade",
+		},
+		{
+			name:     "already has -S flag",
+			input:    "sudo -S apt update",
+			expected: "sudo -S apt update",
+		},
+		{
+			name:     "no sudo",
+			input:    "apt update && apt upgrade",
+			expected: "apt update && apt upgrade",
+		},
+		{
+			name:     "sudo in string (should not match)",
+			input:    "echo 'use sudo carefully'",
+			expected: "echo 'use sudo carefully'",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := rewriteSudoForStdin(tt.input)
+			if result != tt.expected {
+				t.Errorf("rewriteSudoForStdin(%q) = %q, want %q", tt.input, result, tt.expected)
+			}
+		})
+	}
+}
+
+func TestSudoPasswordFromContext(t *testing.T) {
+	// Test with password in context
+	ctx := context.WithValue(context.Background(), sudoPasswordKey, "secret123")
+	pw := sudoPasswordFromContext(ctx)
+	if pw != "secret123" {
+		t.Errorf("expected password 'secret123', got %q", pw)
+	}
+
+	// Test without password
+	ctx = context.Background()
+	pw = sudoPasswordFromContext(ctx)
+	if pw != "" {
+		t.Errorf("expected empty password, got %q", pw)
+	}
+}

internal/core/edit.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"os"
+	"sort"
 	"strings"
 	"unicode"
 	"unicode/utf8"
@@ -13,34 +14,67 @@ import (
 	udiff "github.com/aymanbagabas/go-udiff"
 )
 
-type editArgs struct {
-	Path    string `json:"path"`
+// Edit represents a single replacement in a multi-edit operation.
+type Edit struct {
 	OldText string `json:"old_text"`
 	NewText string `json:"new_text"`
 }
 
+// editArgs holds the arguments for the edit tool.
+type editArgs struct {
+	Path  string `json:"path"`
+	Edits []Edit `json:"edits"`
+}
+
+// replacement represents a normalized edit ready for processing.
+type replacement struct {
+	oldText     string // normalized old text for matching
+	newText     string // normalized new text
+	originalOld string // original old text for metadata
+	originalNew string // original new text for metadata
+	index       int    // index in the original edits array (for error messages)
+}
+
+// matchedReplacement represents a replacement with its match location.
+type matchedReplacement struct {
+	replacement
+	start          int  // start index in normalized content
+	end            int  // end index in normalized content
+	usedFuzzyMatch bool // true if fuzzy matching was used
+}
+
 // NewEditTool creates the edit core tool.
 func NewEditTool(opts ...ToolOption) fantasy.AgentTool {
 	cfg := ApplyOptions(opts)
 	return &coreTool{
 		info: fantasy.ToolInfo{
 			Name:        "edit",
-			Description: "Edit a file by replacing exact text. The old_text must match exactly (including whitespace). Use this for precise, surgical edits. Fails if old_text is not found or matches multiple locations.",
+			Description: "Edit a file by replacing exact text. All edits in the array are matched against the original file content (non-incremental) and must be non-overlapping.",
 			Parameters: map[string]any{
 				"path": map[string]any{
 					"type":        "string",
 					"description": "Path to the file to edit (relative or absolute)",
 				},
-				"old_text": map[string]any{
-					"type":        "string",
-					"description": "Exact text to find and replace (must match exactly)",
-				},
-				"new_text": map[string]any{
-					"type":        "string",
-					"description": "New text to replace the old text with",
+				"edits": map[string]any{
+					"type":        "array",
+					"description": "Array of edits for multi-region replacement. Each edit must have unique, non-overlapping old_text. All matches are against the original file content.",
+					"items": map[string]any{
+						"type": "object",
+						"properties": map[string]any{
+							"old_text": map[string]any{
+								"type":        "string",
+								"description": "Exact text to find and replace for this edit",
+							},
+							"new_text": map[string]any{
+								"type":        "string",
+								"description": "New text for this edit",
+							},
+						},
+						"required": []string{"old_text", "new_text"},
+					},
 				},
 			},
-			Required: []string{"path", "old_text", "new_text"},
+			Required: []string{"path", "edits"},
 		},
 		handler: func(ctx context.Context, call fantasy.ToolCall) (fantasy.ToolResponse, error) {
 			return executeEdit(ctx, call, cfg.WorkDir)
@@ -49,9 +83,12 @@ func NewEditTool(opts ...ToolOption) fantasy.AgentTool {
 }
 
 func executeEdit(ctx context.Context, call fantasy.ToolCall, workDir string) (fantasy.ToolResponse, error) {
+	if err := ctx.Err(); err != nil {
+		return fantasy.ToolResponse{}, err
+	}
 	var args editArgs
 	if err := parseArgs(call.Input, &args); err != nil {
-		return fantasy.NewTextErrorResponse("path, old_text, and new_text parameters are required"), nil
+		return fantasy.NewTextErrorResponse("failed to parse arguments: " + err.Error()), nil
 	}
 	if args.Path == "" {
 		return fantasy.NewTextErrorResponse("path parameter is required"), nil
@@ -69,56 +106,176 @@ func executeEdit(ctx context.Context, call fantasy.ToolCall, workDir string) (fa
 
 	content := string(contentBytes)
 
-	// Normalize line endings for matching
-	normalized := strings.ReplaceAll(content, "\r\n", "\n")
-	normalizedOld := strings.ReplaceAll(args.OldText, "\r\n", "\n")
-
-	// Try exact match first
-	count := strings.Count(normalized, normalizedOld)
-
-	// If no exact match, try fuzzy matching
-	if count == 0 {
-		if idx, matchLen := fuzzyMatch(normalized, normalizedOld); idx >= 0 {
-			// Apply fuzzy match — the matched text is the original content slice
-			matchedText := normalized[idx : idx+matchLen]
-			newContent := normalized[:idx] + args.NewText + normalized[idx+matchLen:]
-			if err := os.WriteFile(absPath, []byte(newContent), 0644); err != nil {
-				return fantasy.NewTextErrorResponse(fmt.Sprintf("failed to write file: %v", err)), nil
-			}
-			diff := generateDiff(absPath, normalized, newContent)
-			resp := fantasy.NewTextResponse(fmt.Sprintf("Applied edit (fuzzy match) to %s\n%s", args.Path, diff))
-			return fantasy.WithResponseMetadata(resp, editDiffMeta(absPath, matchedText, args.NewText)), nil
-		}
-		return fantasy.NewTextErrorResponse(fmt.Sprintf("old_text not found in %s", args.Path)), nil
+	// Normalize and validate input
+	replacements, err := normalizeEditInput(args)
+	if err != nil {
+		return fantasy.NewTextErrorResponse(err.Error()), nil
 	}
 
-	if count > 1 {
-		return fantasy.NewTextErrorResponse(fmt.Sprintf("found %d matches for old_text in %s. Provide more context to identify the correct match.", count, args.Path)), nil
+	// Apply all edits
+	newContent, applied, err := applyEdits(content, replacements)
+	if err != nil {
+		return fantasy.NewTextErrorResponse(err.Error()), nil
 	}
 
-	// Apply the edit
-	newContent := strings.Replace(normalized, normalizedOld, args.NewText, 1)
-
+	// Write the file
 	if err := os.WriteFile(absPath, []byte(newContent), 0644); err != nil {
 		return fantasy.NewTextErrorResponse(fmt.Sprintf("failed to write file: %v", err)), nil
 	}
 
-	diff := generateDiff(absPath, normalized, newContent)
-	resp := fantasy.NewTextResponse(fmt.Sprintf("Applied edit to %s\n%s", args.Path, diff))
-	return fantasy.WithResponseMetadata(resp, editDiffMeta(absPath, normalizedOld, args.NewText)), nil
+	// Generate diff
+	normalizedContent := strings.ReplaceAll(content, "\r\n", "\n")
+	diff := generateDiff(absPath, normalizedContent, newContent)
+
+	// Build response with fuzzy match indication
+	fuzzyCount := 0
+	for _, m := range applied {
+		if m.usedFuzzyMatch {
+			fuzzyCount++
+		}
+	}
+
+	var msg string
+	if len(applied) == 1 {
+		if fuzzyCount > 0 {
+			msg = fmt.Sprintf("Applied edit (fuzzy match) to %s\n%s", args.Path, diff)
+		} else {
+			msg = fmt.Sprintf("Applied edit to %s\n%s", args.Path, diff)
+		}
+	} else {
+		if fuzzyCount > 0 {
+			msg = fmt.Sprintf("Applied %d edits (%d fuzzy) to %s\n%s", len(applied), fuzzyCount, args.Path, diff)
+		} else {
+			msg = fmt.Sprintf("Applied %d edits to %s\n%s", len(applied), args.Path, diff)
+		}
+	}
+
+	resp := fantasy.NewTextResponse(msg)
+	return fantasy.WithResponseMetadata(resp, editDiffMeta(absPath, applied)), nil
+}
+
+// normalizeEditInput validates and normalizes the edit input.
+func normalizeEditInput(args editArgs) ([]replacement, error) {
+	if len(args.Edits) == 0 {
+		return nil, fmt.Errorf("edits array is required and must not be empty")
+	}
+
+	var reps []replacement
+	for i, edit := range args.Edits {
+		if edit.OldText == "" {
+			return nil, fmt.Errorf("edits[%d].old_text is required", i)
+		}
+		reps = append(reps, replacement{
+			oldText:     strings.ReplaceAll(edit.OldText, "\r\n", "\n"),
+			newText:     strings.ReplaceAll(edit.NewText, "\r\n", "\n"),
+			originalOld: edit.OldText,
+			originalNew: edit.NewText,
+			index:       i,
+		})
+	}
+	return reps, nil
+}
+
+// applyEdits applies multiple replacements to the content.
+// All matches are against the original content (non-incremental).
+// Returns the new content, the applied matches, and any error.
+func applyEdits(content string, edits []replacement) (string, []matchedReplacement, error) {
+	normalizedContent := strings.ReplaceAll(content, "\r\n", "\n")
+
+	// Find all matches
+	var matched []matchedReplacement
+	for _, edit := range edits {
+		m, err := findMatch(normalizedContent, edit)
+		if err != nil {
+			return "", nil, err
+		}
+		matched = append(matched, *m)
+	}
+
+	// Sort by position
+	sort.Slice(matched, func(i, j int) bool {
+		return matched[i].start < matched[j].start
+	})
+
+	// Check for overlaps
+	for i := 1; i < len(matched); i++ {
+		if matched[i-1].end > matched[i].start {
+			return "", nil, fmt.Errorf("edits[%d] and edits[%d] overlap; merge them into a single edit",
+				matched[i-1].index, matched[i].index)
+		}
+	}
+
+	// Apply edits in reverse order (end to start) to maintain stable offsets
+	result := normalizedContent
+	for i := len(matched) - 1; i >= 0; i-- {
+		m := matched[i]
+		result = result[:m.start] + m.newText + result[m.end:]
+	}
+
+	return result, matched, nil
+}
+
+// findMatch finds a unique match for the edit in the content.
+// Returns error if not found or ambiguous.
+func findMatch(content string, edit replacement) (*matchedReplacement, error) {
+	// Try exact match first
+	count := strings.Count(content, edit.oldText)
+
+	if count == 0 {
+		// Try fuzzy match
+		idx, matchLen := fuzzyMatch(content, edit.oldText)
+		if idx < 0 {
+			return nil, fmt.Errorf("edits[%d]: could not find old_text in file. The text must match exactly (including whitespace)", edit.index)
+		}
+		// Use the matched text from content for the replacement
+		matchedText := content[idx : idx+matchLen]
+		return &matchedReplacement{
+			replacement: replacement{
+				oldText:     matchedText,
+				newText:     edit.newText,
+				originalOld: edit.originalOld,
+				originalNew: edit.originalNew,
+				index:       edit.index,
+			},
+			start:          idx,
+			end:            idx + matchLen,
+			usedFuzzyMatch: true,
+		}, nil
+	}
+
+	if count > 1 {
+		return nil, fmt.Errorf("found %d matches for edits[%d].old_text; each old_text must be unique, provide more context to identify the correct match", count, edit.index)
+	}
+
+	// Single exact match
+	idx := strings.Index(content, edit.oldText)
+	return &matchedReplacement{
+		replacement: edit,
+		start:       idx,
+		end:         idx + len(edit.oldText),
+	}, nil
 }
 
 // editDiffMeta builds the structured metadata attached to edit tool responses.
-func editDiffMeta(path, oldText, newText string) map[string]any {
+func editDiffMeta(path string, applied []matchedReplacement) map[string]any {
+	var diffBlocks []map[string]any
+	totalAdditions, totalDeletions := 0, 0
+
+	for _, m := range applied {
+		diffBlocks = append(diffBlocks, map[string]any{
+			"old_text": m.originalOld,
+			"new_text": m.originalNew,
+		})
+		totalAdditions += strings.Count(m.originalNew, "\n") + 1
+		totalDeletions += strings.Count(m.originalOld, "\n") + 1
+	}
+
 	return map[string]any{
 		"file_diffs": []map[string]any{{
-			"path":      path,
-			"additions": strings.Count(newText, "\n") + 1,
-			"deletions": strings.Count(oldText, "\n") + 1,
-			"diff_blocks": []map[string]any{{
-				"old_text": oldText,
-				"new_text": newText,
-			}},
+			"path":        path,
+			"additions":   totalAdditions,
+			"deletions":   totalDeletions,
+			"diff_blocks": diffBlocks,
 		}},
 	}
 }

internal/core/edit_test.go

@@ -389,9 +389,11 @@ func TestExecuteEdit_ExactMatch(t *testing.T) {
 	writeFileOrFail(t, path, original)
 
 	input, _ := json.Marshal(editArgs{
-		Path:    path,
-		OldText: "fmt.Println(\"hello\")",
-		NewText: "fmt.Println(\"world\")",
+		Path: path,
+		Edits: []Edit{{
+			OldText: "fmt.Println(\"hello\")",
+			NewText: "fmt.Println(\"world\")",
+		}},
 	})
 
 	resp, err := executeEdit(t.Context(), fantasy.ToolCall{Input: string(input)}, dir)
@@ -426,9 +428,11 @@ func TestExecuteEdit_ExactMatch_DoesNotCorruptRest(t *testing.T) {
 	target := lines[49]
 	replacement := "REPLACED_LINE_50"
 	input, _ := json.Marshal(editArgs{
-		Path:    path,
-		OldText: target,
-		NewText: replacement,
+		Path: path,
+		Edits: []Edit{{
+			OldText: target,
+			NewText: replacement,
+		}},
 	})
 
 	resp, err := executeEdit(t.Context(), fantasy.ToolCall{Input: string(input)}, dir)
@@ -470,9 +474,11 @@ func TestExecuteEdit_FuzzyMatch_TrailingWhitespace(t *testing.T) {
 
 	// Search without trailing whitespace (common LLM behavior)
 	input, _ := json.Marshal(editArgs{
-		Path:    path,
-		OldText: "func foo() {\n\treturn 1\n}",
-		NewText: "func foo() {\n\treturn 2\n}",
+		Path: path,
+		Edits: []Edit{{
+			OldText: "func foo() {\n\treturn 1\n}",
+			NewText: "func foo() {\n\treturn 2\n}",
+		}},
 	})
 
 	resp, err := executeEdit(t.Context(), fantasy.ToolCall{Input: string(input)}, dir)
@@ -519,9 +525,11 @@ func TestExecuteEdit_FuzzyMatch_DoesNotCorruptRest(t *testing.T) {
 	search := strings.Repeat("x", 10) + "\n" + strings.Repeat("x", 10)
 	// But this matches lines 1-2, 2-3, etc. — should fail due to ambiguity.
 	input, _ := json.Marshal(editArgs{
-		Path:    path,
-		OldText: search,
-		NewText: "REPLACED",
+		Path: path,
+		Edits: []Edit{{
+			OldText: search,
+			NewText: "REPLACED",
+		}},
 	})
 
 	resp, err := executeEdit(t.Context(), fantasy.ToolCall{Input: string(input)}, dir)
@@ -546,9 +554,11 @@ func TestExecuteEdit_MultipleMatches_Fails(t *testing.T) {
 	writeFileOrFail(t, path, "hello\nworld\nhello\n")
 
 	input, _ := json.Marshal(editArgs{
-		Path:    path,
-		OldText: "hello",
-		NewText: "goodbye",
+		Path: path,
+		Edits: []Edit{{
+			OldText: "hello",
+			NewText: "goodbye",
+		}},
 	})
 
 	resp, err := executeEdit(t.Context(), fantasy.ToolCall{Input: string(input)}, dir)
@@ -575,9 +585,11 @@ func TestExecuteEdit_NoMatch_Fails(t *testing.T) {
 	writeFileOrFail(t, path, "hello world\n")
 
 	input, _ := json.Marshal(editArgs{
-		Path:    path,
-		OldText: "nonexistent text",
-		NewText: "replacement",
+		Path: path,
+		Edits: []Edit{{
+			OldText: "nonexistent text",
+			NewText: "replacement",
+		}},
 	})
 
 	resp, err := executeEdit(t.Context(), fantasy.ToolCall{Input: string(input)}, dir)
@@ -601,9 +613,11 @@ func TestExecuteEdit_CRLFNormalization(t *testing.T) {
 	writeFileOrFail(t, path, "line1\r\nline2\r\nline3\r\n")
 
 	input, _ := json.Marshal(editArgs{
-		Path:    path,
-		OldText: "line2",
-		NewText: "LINE2",
+		Path: path,
+		Edits: []Edit{{
+			OldText: "line2",
+			NewText: "LINE2",
+		}},
 	})
 
 	resp, err := executeEdit(t.Context(), fantasy.ToolCall{Input: string(input)}, dir)
@@ -622,8 +636,10 @@ func TestExecuteEdit_CRLFNormalization(t *testing.T) {
 
 func TestExecuteEdit_MissingPath(t *testing.T) {
 	input, _ := json.Marshal(editArgs{
-		OldText: "x",
-		NewText: "y",
+		Edits: []Edit{{
+			OldText: "x",
+			NewText: "y",
+		}},
 	})
 	resp, err := executeEdit(t.Context(), fantasy.ToolCall{Input: string(input)}, "")
 	if err != nil {
@@ -636,9 +652,11 @@ func TestExecuteEdit_MissingPath(t *testing.T) {
 
 func TestExecuteEdit_NonexistentFile(t *testing.T) {
 	input, _ := json.Marshal(editArgs{
-		Path:    "/tmp/nonexistent_edit_test_file_12345.go",
-		OldText: "x",
-		NewText: "y",
+		Path: "/tmp/nonexistent_edit_test_file_12345.go",
+		Edits: []Edit{{
+			OldText: "x",
+			NewText: "y",
+		}},
 	})
 	resp, err := executeEdit(t.Context(), fantasy.ToolCall{Input: string(input)}, "")
 	if err != nil {
@@ -661,9 +679,11 @@ func TestExecuteEdit_DiffContainsHunkHeader(t *testing.T) {
 	writeFileOrFail(t, path, strings.Join(lines, "\n")+"\n")
 
 	input, _ := json.Marshal(editArgs{
-		Path:    path,
-		OldText: "line_10_content",
-		NewText: "REPLACED",
+		Path: path,
+		Edits: []Edit{{
+			OldText: "line_10_content",
+			NewText: "REPLACED",
+		}},
 	})
 
 	resp, err := executeEdit(t.Context(), fantasy.ToolCall{Input: string(input)}, dir)
@@ -684,9 +704,11 @@ func TestExecuteEdit_MetadataContainsFileDiffs(t *testing.T) {
 	writeFileOrFail(t, path, "old content\n")
 
 	input, _ := json.Marshal(editArgs{
-		Path:    path,
-		OldText: "old content",
-		NewText: "new content",
+		Path: path,
+		Edits: []Edit{{
+			OldText: "old content",
+			NewText: "new content",
+		}},
 	})
 
 	resp, err := executeEdit(t.Context(), fantasy.ToolCall{Input: string(input)}, dir)
@@ -715,3 +737,311 @@ func TestExecuteEdit_MetadataContainsFileDiffs(t *testing.T) {
 		t.Fatal("file_diffs should be a non-empty array")
 	}
 }
+
+// ---------------------------------------------------------------------------
+// Multi-edit tests
+// ---------------------------------------------------------------------------
+
+func TestExecuteEdit_MultiEdit_Basic(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "multi.txt")
+	writeFileOrFail(t, path, "line1\nline2\nline3\nline4\n")
+
+	input, _ := json.Marshal(editArgs{
+		Path: path,
+		Edits: []Edit{
+			{OldText: "line1", NewText: "LINE1"},
+			{OldText: "line3", NewText: "LINE3"},
+		},
+	})
+
+	resp, err := executeEdit(t.Context(), fantasy.ToolCall{Input: string(input)}, dir)
+	if err != nil {
+		t.Fatalf("executeEdit error: %v", err)
+	}
+	if resp.IsError {
+		t.Fatalf("tool returned error: %s", resp.Content)
+	}
+
+	got, _ := os.ReadFile(path)
+	gotStr := string(got)
+
+	if !strings.Contains(gotStr, "LINE1") {
+		t.Error("first edit not applied: missing LINE1")
+	}
+	if !strings.Contains(gotStr, "LINE3") {
+		t.Error("second edit not applied: missing LINE3")
+	}
+	if !strings.Contains(gotStr, "line2") {
+		t.Error("line2 was modified but should be untouched")
+	}
+	if !strings.Contains(gotStr, "line4") {
+		t.Error("line4 was modified but should be untouched")
+	}
+
+	// Check response mentions multiple edits
+	if !strings.Contains(resp.Content, "2 edits") {
+		t.Errorf("response should mention '2 edits', got: %s", resp.Content)
+	}
+}
+
+func TestExecuteEdit_MultiEdit_NonIncrementalMatching(t *testing.T) {
+	// All edits are matched against the original content, not incrementally
+	dir := t.TempDir()
+	path := filepath.Join(dir, "noninc.txt")
+	writeFileOrFail(t, path, "aaa\nbbb\nccc\n")
+
+	input, _ := json.Marshal(editArgs{
+		Path: path,
+		Edits: []Edit{
+			{OldText: "aaa", NewText: "AAA"},
+			{OldText: "bbb", NewText: "BBB"},
+		},
+	})
+
+	resp, err := executeEdit(t.Context(), fantasy.ToolCall{Input: string(input)}, dir)
+	if err != nil {
+		t.Fatalf("executeEdit error: %v", err)
+	}
+	if resp.IsError {
+		t.Fatalf("tool returned error: %s", resp.Content)
+	}
+
+	got, _ := os.ReadFile(path)
+	gotStr := string(got)
+
+	want := "AAA\nBBB\nccc\n"
+	if gotStr != want {
+		t.Errorf("got %q, want %q", gotStr, want)
+	}
+}
+
+func TestExecuteEdit_MultiEdit_OverlapDetection(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "overlap.txt")
+	writeFileOrFail(t, path, "hello world\n")
+
+	input, _ := json.Marshal(editArgs{
+		Path: path,
+		Edits: []Edit{
+			{OldText: "hello", NewText: "HELLO"},
+			{OldText: "hello world", NewText: "GOODBYE"}, // Overlaps with first edit
+		},
+	})
+
+	resp, err := executeEdit(t.Context(), fantasy.ToolCall{Input: string(input)}, dir)
+	if err != nil {
+		t.Fatalf("executeEdit error: %v", err)
+	}
+	if !resp.IsError {
+		t.Error("expected error for overlapping edits")
+	}
+	if !strings.Contains(resp.Content, "overlap") {
+		t.Errorf("expected 'overlap' in error, got: %s", resp.Content)
+	}
+
+	// File should be untouched
+	got, _ := os.ReadFile(path)
+	if string(got) != "hello world\n" {
+		t.Error("file was modified despite error")
+	}
+}
+
+func TestExecuteEdit_MultiEdit_DuplicateDetection(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "dup.txt")
+	writeFileOrFail(t, path, "hello\nworld\nhello\n")
+
+	input, _ := json.Marshal(editArgs{
+		Path: path,
+		Edits: []Edit{
+			{OldText: "hello", NewText: "HELLO"},
+			{OldText: "world", NewText: "WORLD"},
+		},
+	})
+
+	resp, err := executeEdit(t.Context(), fantasy.ToolCall{Input: string(input)}, dir)
+	if err != nil {
+		t.Fatalf("executeEdit error: %v", err)
+	}
+	if !resp.IsError {
+		t.Error("expected error for ambiguous old_text (duplicate matches)")
+	}
+	if !strings.Contains(resp.Content, "unique") {
+		t.Errorf("expected 'unique' in error, got: %s", resp.Content)
+	}
+
+	// File should be untouched
+	got, _ := os.ReadFile(path)
+	if string(got) != "hello\nworld\nhello\n" {
+		t.Error("file was modified despite error")
+	}
+}
+
+func TestExecuteEdit_MultiEdit_NotFound(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "notfound.txt")
+	writeFileOrFail(t, path, "hello world\n")
+
+	input, _ := json.Marshal(editArgs{
+		Path: path,
+		Edits: []Edit{
+			{OldText: "nonexistent", NewText: "REPLACEMENT"},
+		},
+	})
+
+	resp, err := executeEdit(t.Context(), fantasy.ToolCall{Input: string(input)}, dir)
+	if err != nil {
+		t.Fatalf("executeEdit error: %v", err)
+	}
+	if !resp.IsError {
+		t.Error("expected error for not found")
+	}
+	if !strings.Contains(resp.Content, "edits[0]") {
+		t.Errorf("expected 'edits[0]' in error, got: %s", resp.Content)
+	}
+
+	// File should be untouched
+	got, _ := os.ReadFile(path)
+	if string(got) != "hello world\n" {
+		t.Error("file was modified despite error")
+	}
+}
+
+func TestExecuteEdit_MultiEdit_EmptyArray(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "empty.txt")
+	writeFileOrFail(t, path, "hello\n")
+
+	input, _ := json.Marshal(editArgs{
+		Path:  path,
+		Edits: []Edit{},
+	})
+
+	resp, err := executeEdit(t.Context(), fantasy.ToolCall{Input: string(input)}, dir)
+	if err != nil {
+		t.Fatalf("executeEdit error: %v", err)
+	}
+	if !resp.IsError {
+		t.Error("expected error for empty edits array")
+	}
+}
+
+func TestExecuteEdit_EmptyEditsArray_Fails(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "empty.txt")
+	writeFileOrFail(t, path, "hello\n")
+
+	input, _ := json.Marshal(editArgs{
+		Path:  path,
+		Edits: []Edit{},
+	})
+
+	resp, err := executeEdit(t.Context(), fantasy.ToolCall{Input: string(input)}, dir)
+	if err != nil {
+		t.Fatalf("executeEdit error: %v", err)
+	}
+	if !resp.IsError {
+		t.Error("expected error for empty edits array")
+	}
+	if !strings.Contains(resp.Content, "required") {
+		t.Errorf("expected 'required' in error, got: %s", resp.Content)
+	}
+}
+
+func TestExecuteEdit_MultiEdit_FuzzyMatch(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "fuzzy_multi.txt")
+	// File has trailing whitespace
+	original := "func foo() {   \n\treturn 1   \n}\nfunc bar() {   \n\treturn 2   \n}\n"
+	writeFileOrFail(t, path, original)
+
+	// Search without trailing whitespace (common LLM behavior)
+	input, _ := json.Marshal(editArgs{
+		Path: path,
+		Edits: []Edit{
+			{OldText: "func foo() {\n\treturn 1\n}", NewText: "func foo() {\n\treturn 10\n}"},
+			{OldText: "func bar() {\n\treturn 2\n}", NewText: "func bar() {\n\treturn 20\n}"},
+		},
+	})
+
+	resp, err := executeEdit(t.Context(), fantasy.ToolCall{Input: string(input)}, dir)
+	if err != nil {
+		t.Fatalf("executeEdit error: %v", err)
+	}
+	if resp.IsError {
+		t.Fatalf("tool returned error: %s", resp.Content)
+	}
+
+	got, _ := os.ReadFile(path)
+	gotStr := string(got)
+
+	if !strings.Contains(gotStr, "return 10") {
+		t.Error("first edit not applied")
+	}
+	if !strings.Contains(gotStr, "return 20") {
+		t.Error("second edit not applied")
+	}
+
+	// Response should mention fuzzy match
+	if !strings.Contains(resp.Content, "fuzzy") {
+		t.Errorf("response should mention 'fuzzy', got: %s", resp.Content)
+	}
+}
+
+func TestExecuteEdit_MultiEdit_Metadata(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "meta_multi.txt")
+	writeFileOrFail(t, path, "aaa\nbbb\nccc\n")
+
+	input, _ := json.Marshal(editArgs{
+		Path: path,
+		Edits: []Edit{
+			{OldText: "aaa", NewText: "AAA"},
+			{OldText: "bbb", NewText: "BBB"},
+		},
+	})
+
+	resp, err := executeEdit(t.Context(), fantasy.ToolCall{Input: string(input)}, dir)
+	if err != nil {
+		t.Fatalf("error: %v", err)
+	}
+	if resp.IsError {
+		t.Fatalf("tool returned error: %s", resp.Content)
+	}
+
+	var meta map[string]any
+	if err := json.Unmarshal([]byte(resp.Metadata), &meta); err != nil {
+		t.Fatalf("metadata is not valid JSON: %v", err)
+	}
+
+	diffs, ok := meta["file_diffs"].([]any)
+	if !ok || len(diffs) == 0 {
+		t.Fatal("metadata missing file_diffs")
+	}
+
+	firstDiff, ok := diffs[0].(map[string]any)
+	if !ok {
+		t.Fatal("first diff is not an object")
+	}
+
+	// Check that diff_blocks contains both edits
+	diffBlocks, ok := firstDiff["diff_blocks"].([]any)
+	if !ok || len(diffBlocks) != 2 {
+		t.Fatalf("expected 2 diff_blocks, got %d", len(diffBlocks))
+	}
+
+	// Verify each block has old_text and new_text
+	for i, block := range diffBlocks {
+		b, ok := block.(map[string]any)
+		if !ok {
+			t.Fatalf("diff_block[%d] is not an object", i)
+		}
+		if _, ok := b["old_text"]; !ok {
+			t.Fatalf("diff_block[%d] missing old_text", i)
+		}
+		if _, ok := b["new_text"]; !ok {
+			t.Fatalf("diff_block[%d] missing new_text", i)
+		}
+	}
+}

internal/core/ls.go

@@ -42,6 +42,9 @@ func NewLsTool(opts ...ToolOption) fantasy.AgentTool {
 }
 
 func executeLs(ctx context.Context, call fantasy.ToolCall, workDir string) (fantasy.ToolResponse, error) {
+	if err := ctx.Err(); err != nil {
+		return fantasy.ToolResponse{}, err
+	}
 	var args lsArgs
 	_ = parseArgs(call.Input, &args) // optional args
 

internal/core/read.go

@@ -47,6 +47,9 @@ func NewReadTool(opts ...ToolOption) fantasy.AgentTool {
 }
 
 func executeRead(ctx context.Context, call fantasy.ToolCall, workDir string) (fantasy.ToolResponse, error) {
+	if err := ctx.Err(); err != nil {
+		return fantasy.ToolResponse{}, err
+	}
 	var args readArgs
 	if err := parseArgs(call.Input, &args); err != nil {
 		return fantasy.NewTextErrorResponse("path parameter is required"), nil
@@ -67,7 +70,7 @@ func executeRead(ctx context.Context, call fantasy.ToolCall, workDir string) (fa
 	}
 
 	if info.IsDir() {
-		return readDirectory(absPath)
+		return fantasy.NewTextErrorResponse(fmt.Sprintf("'%s' is a directory, not a file. Use the ls tool to list directory contents.", args.Path)), nil
 	}
 
 	content, err := os.ReadFile(absPath)
@@ -116,25 +119,6 @@ func executeRead(ctx context.Context, call fantasy.ToolCall, workDir string) (fa
 	return fantasy.NewTextResponse(tr.Content), nil
 }
 
-func readDirectory(absPath string) (fantasy.ToolResponse, error) {
-	entries, err := os.ReadDir(absPath)
-	if err != nil {
-		return fantasy.NewTextErrorResponse(fmt.Sprintf("failed to read directory: %v", err)), nil
-	}
-
-	var result strings.Builder
-	for _, entry := range entries {
-		name := entry.Name()
-		if entry.IsDir() {
-			name += "/"
-		}
-		result.WriteString(name + "\n")
-	}
-
-	tr := truncateHead(result.String(), 500, defaultMaxBytes)
-	return fantasy.NewTextResponse(tr.Content), nil
-}
-
 // resolvePathWithWorkDir resolves a path to an absolute path relative to the
 // given workDir. If workDir is empty, os.Getwd() is used.
 func resolvePathWithWorkDir(path, workDir string) (string, error) {

internal/core/subagent.go

@@ -28,14 +28,14 @@ type SubagentSpawnResult struct {
 // SubagentSpawnFunc is a callback that spawns an in-process subagent. The
 // parent Kit instance injects this into the context so the core tool can
 // call back without importing pkg/kit (which would create a cycle).
-// The toolCallID parameter is the LLM-assigned ID of the spawn_subagent
+// The toolCallID parameter is the LLM-assigned ID of the subagent
 // tool call, enabling the parent to correlate subagent events.
 type SubagentSpawnFunc func(ctx context.Context, toolCallID, prompt, model, systemPrompt string, timeout time.Duration) (*SubagentSpawnResult, error)
 
 type subagentCtxKey struct{}
 
 // WithSubagentSpawner stores a spawn function in the context so that the
-// spawn_subagent core tool can create in-process subagents.
+// subagent core tool can create in-process subagents.
 func WithSubagentSpawner(ctx context.Context, fn SubagentSpawnFunc) context.Context {
 	return context.WithValue(ctx, subagentCtxKey{}, fn)
 }
@@ -49,7 +49,7 @@ func getSubagentSpawner(ctx context.Context) SubagentSpawnFunc {
 }
 
 // ---------------------------------------------------------------------------
-// spawn_subagent tool
+// subagent tool
 // ---------------------------------------------------------------------------
 
 type subagentArgs struct {
@@ -59,11 +59,11 @@ type subagentArgs struct {
 	TimeoutSeconds int    `json:"timeout_seconds,omitempty"`
 }
 
-// NewSubagentTool creates the spawn_subagent core tool.
+// NewSubagentTool creates the subagent core tool.
 func NewSubagentTool(opts ...ToolOption) fantasy.AgentTool {
 	return &coreTool{
 		info: fantasy.ToolInfo{
-			Name: "spawn_subagent",
+			Name: "subagent",
 			Description: `Spawn a subagent to perform a task autonomously.
 
 The subagent runs as a separate in-process Kit instance with full tool access
@@ -86,7 +86,7 @@ Example use cases:
 				},
 				"model": map[string]any{
 					"type":        "string",
-					"description": "Optional model override (e.g. 'anthropic/claude-haiku-3-5-20241022' for faster/cheaper tasks)",
+					"description": "Optional model override. Empty string uses the current model.",
 				},
 				"system_prompt": map[string]any{
 					"type":        "string",
@@ -94,7 +94,7 @@ Example use cases:
 				},
 				"timeout_seconds": map[string]any{
 					"type":        "number",
-					"description": "Maximum execution time in seconds (default: 300, max: 1800)",
+					"description": "Maximum execution time in seconds (default: 300, max: 1800, minimum recommended: 240)",
 				},
 			},
 			Required: []string{"task"},
@@ -130,13 +130,22 @@ func executeSubagent(ctx context.Context, call fantasy.ToolCall) (fantasy.ToolRe
 		), fmt.Errorf("no subagent spawner in context")
 	}
 
-	// Detach from the parent's deadline so the subagent gets its own
-	// independent timeout (applied downstream in Kit.Subagent). The parent
-	// context may carry a tight deadline from the LLM generation loop or
-	// other tool timeouts that would prematurely kill the subagent.
-	// We preserve context values (spawner, etc.) and propagate parent
-	// cancellation (e.g. user hits Ctrl-C) without inheriting the deadline.
-	spawnCtx := detachedWithCancel(ctx)
+	// Build a clean context for the subagent that inherits values (e.g. the
+	// spawner callback) but is completely detached from the parent's
+	// deadline AND cancellation. The subagent gets its own independent
+	// timeout (applied downstream in Kit.Subagent).
+	//
+	// Why full detachment instead of propagating parent cancellation?
+	// The parent context may already be done (deadline exceeded or
+	// cancelled) by the time this tool handler executes — for example when
+	// the generation loop context carries a deadline, when the user
+	// double-ESC cancels mid-turn, or when parallel tool execution
+	// encounters a race between stream completion and tool dispatch. Using
+	// context.WithoutCancel (Go 1.21+) ensures the subagent always starts
+	// cleanly with a fresh timeout, following the pattern used by crush for
+	// shutdown-resilient child work. The subagent's own timeout
+	// (defaultSubagentTimeout / user-specified) provides the safety net.
+	spawnCtx := context.WithoutCancel(valuesContext{parent: ctx})
 
 	// Spawn in-process subagent.
 	result, err := spawner(spawnCtx, call.ID, args.Task, args.Model, args.SystemPrompt, timeout)
@@ -173,37 +182,21 @@ func executeSubagent(ctx context.Context, call fantasy.ToolCall) (fantasy.ToolRe
 }
 
 // ---------------------------------------------------------------------------
-// Context detachment
+// Context helpers
 // ---------------------------------------------------------------------------
 
-// detachedContext wraps a parent context, preserving its values but removing
-// its deadline and cancellation. This allows the subagent to have its own
-// independent timeout while still accessing context-stored values (e.g. the
-// subagent spawner function).
-type detachedContext struct {
+// valuesContext preserves a parent context's values (e.g. the subagent
+// spawner callback) while stripping its deadline and cancellation. Combined
+// with context.WithoutCancel() this gives the subagent a completely clean
+// context that only inherits value-based dependencies.
+type valuesContext struct {
 	parent context.Context
 }
 
-func (d detachedContext) Deadline() (time.Time, bool) { return time.Time{}, false }
-func (d detachedContext) Done() <-chan struct{}       { return nil }
-func (d detachedContext) Err() error                  { return nil }
-func (d detachedContext) Value(key any) any           { return d.parent.Value(key) }
-
-// detachedWithCancel creates a new context that inherits values from the
-// parent but has no deadline. Cancellation of the parent is propagated: when
-// the parent is cancelled the returned context is also cancelled, but the
-// parent's deadline does not apply to the child.
-func detachedWithCancel(parent context.Context) context.Context {
-	child, cancel := context.WithCancel(detachedContext{parent: parent})
-	go func() {
-		select {
-		case <-parent.Done():
-			cancel()
-		case <-child.Done():
-		}
-	}()
-	return child
-}
+func (v valuesContext) Deadline() (time.Time, bool) { return time.Time{}, false }
+func (v valuesContext) Done() <-chan struct{}       { return nil }
+func (v valuesContext) Err() error                  { return nil }
+func (v valuesContext) Value(key any) any           { return v.parent.Value(key) }
 
 // truncateResponse limits the response length to avoid overwhelming context windows.
 func truncateResponse(s string, maxLen int) string {

internal/core/subagent_test.go

@@ -0,0 +1,115 @@
+package core
+
+import (
+	"context"
+	"testing"
+	"time"
+)
+
+func TestValuesContext_StripsDeadlineAndCancellation(t *testing.T) {
+	// Parent with a tight deadline.
+	parent, cancel := context.WithTimeout(context.Background(), 1*time.Millisecond)
+	defer cancel()
+	time.Sleep(5 * time.Millisecond) // Let deadline expire.
+
+	if parent.Err() == nil {
+		t.Fatal("expected parent to be expired")
+	}
+
+	vc := valuesContext{parent: parent}
+
+	if _, ok := vc.Deadline(); ok {
+		t.Error("valuesContext should report no deadline")
+	}
+	if vc.Done() != nil {
+		t.Error("valuesContext.Done() should return nil")
+	}
+	if vc.Err() != nil {
+		t.Errorf("valuesContext.Err() should be nil, got %v", vc.Err())
+	}
+}
+
+func TestValuesContext_PreservesValues(t *testing.T) {
+	type testKey struct{}
+	parent := context.WithValue(context.Background(), testKey{}, "hello")
+
+	vc := valuesContext{parent: parent}
+
+	got, ok := vc.Value(testKey{}).(string)
+	if !ok || got != "hello" {
+		t.Errorf("expected value 'hello', got %q (ok=%v)", got, ok)
+	}
+}
+
+func TestSpawnContext_SurvivesCancelledParent(t *testing.T) {
+	// Simulate the exact scenario from the bug: the parent generation
+	// context is already cancelled when the subagent tool handler runs.
+	parent, cancel := context.WithCancel(context.Background())
+	cancel() // Cancelled before detach.
+
+	// This is what executeSubagent now does:
+	spawnCtx := context.WithoutCancel(valuesContext{parent: parent})
+
+	// The spawn context must be alive.
+	if spawnCtx.Err() != nil {
+		t.Fatalf("spawnCtx should be alive, got err: %v", spawnCtx.Err())
+	}
+
+	// Adding a timeout should produce a working context.
+	tCtx, tCancel := context.WithTimeout(spawnCtx, 5*time.Second)
+	defer tCancel()
+
+	if tCtx.Err() != nil {
+		t.Fatalf("timeout context should be alive, got err: %v", tCtx.Err())
+	}
+}
+
+func TestSpawnContext_SurvivesDeadlineExceededParent(t *testing.T) {
+	// Simulate: parent had a deadline that already expired.
+	parent, pCancel := context.WithTimeout(context.Background(), 1*time.Millisecond)
+	defer pCancel()
+	time.Sleep(5 * time.Millisecond)
+
+	if parent.Err() != context.DeadlineExceeded {
+		t.Fatalf("expected parent deadline exceeded, got: %v", parent.Err())
+	}
+
+	spawnCtx := context.WithoutCancel(valuesContext{parent: parent})
+
+	if spawnCtx.Err() != nil {
+		t.Fatalf("spawnCtx should be alive after deadline-exceeded parent, got: %v", spawnCtx.Err())
+	}
+}
+
+func TestSpawnContext_PreservesSpawnerValue(t *testing.T) {
+	// Verify the subagent spawner callback survives context detachment.
+	called := false
+	spawner := SubagentSpawnFunc(func(ctx context.Context, toolCallID, prompt, model, systemPrompt string, timeout time.Duration) (*SubagentSpawnResult, error) {
+		called = true
+		return &SubagentSpawnResult{Response: "ok"}, nil
+	})
+
+	parent := WithSubagentSpawner(context.Background(), spawner)
+	// Cancel the parent.
+	parentCtx, cancel := context.WithCancel(parent)
+	cancel()
+
+	spawnCtx := context.WithoutCancel(valuesContext{parent: parentCtx})
+
+	// Should be able to retrieve the spawner from the detached context.
+	recovered := getSubagentSpawner(spawnCtx)
+	if recovered == nil {
+		t.Fatal("spawner should be recoverable from detached context")
+	}
+
+	result, err := recovered(spawnCtx, "tc1", "test task", "", "", time.Minute)
+	if err != nil {
+		t.Fatalf("spawner call failed: %v", err)
+	}
+	if !called {
+		t.Error("spawner was not called")
+	}
+	if result.Response != "ok" {
+		t.Errorf("expected 'ok', got %q", result.Response)
+	}
+}

internal/core/tools.go

@@ -86,7 +86,7 @@ func ReadOnlyTools(opts ...ToolOption) []fantasy.AgentTool {
 	}
 }
 
-// SubagentTools returns all core tools except spawn_subagent. This prevents
+// SubagentTools returns all core tools except subagent. This prevents
 // infinite recursion when a subagent is itself a Kit instance.
 func SubagentTools(opts ...ToolOption) []fantasy.AgentTool {
 	return []fantasy.AgentTool{

internal/core/write.go

@@ -41,6 +41,9 @@ func NewWriteTool(opts ...ToolOption) fantasy.AgentTool {
 }
 
 func executeWrite(ctx context.Context, call fantasy.ToolCall, workDir string) (fantasy.ToolResponse, error) {
+	if err := ctx.Err(); err != nil {
+		return fantasy.ToolResponse{}, err
+	}
 	var args writeArgs
 	if err := parseArgs(call.Input, &args); err != nil {
 		return fantasy.NewTextErrorResponse("path and content parameters are required"), nil

internal/extbridge/context.go

@@ -0,0 +1,234 @@
+package extbridge
+
+import (
+	"context"
+
+	"github.com/mark3labs/kit/internal/extensions"
+	kit "github.com/mark3labs/kit/pkg/kit"
+)
+
+// BaseContext returns an extensions.Context populated with the headless,
+// TUI-independent delegation fields: data access, state, options,
+// model/tool management, completions, subagents, tree navigation, skills,
+// template parsing, and model resolution.
+//
+// Callers overlay their UI-specific fields (print routes, widgets, prompts,
+// editor, TUI-aware SetModel/ReloadExtensions, etc.) on the returned value:
+// cmd/extension_context.go for the interactive TUI and
+// internal/acpserver/session.go for headless ACP mode. Keeping the shared
+// half here means a new data-access Context field only has to be wired once.
+//
+// ctx is used for subagent spawns; pass a long-lived context (not a
+// per-request one) so later spawns aren't cancelled prematurely.
+func BaseContext(ctx context.Context, kitInstance *kit.Kit) extensions.Context {
+	return extensions.Context{
+		// -------------------------------------------------------------------
+		// Data access
+		// -------------------------------------------------------------------
+		GetContextStats: func() extensions.ContextStats {
+			s := kitInstance.GetContextStats()
+			return extensions.ContextStats{
+				EstimatedTokens: s.EstimatedTokens,
+				ContextLimit:    s.ContextLimit,
+				UsagePercent:    s.UsagePercent,
+				MessageCount:    s.MessageCount,
+			}
+		},
+		GetMessages: func() []extensions.SessionMessage {
+			return kitInstance.Extensions().GetSessionMessages()
+		},
+		GetSessionPath: func() string {
+			return kitInstance.GetSessionPath()
+		},
+		AppendEntry: func(entryType string, data string) (string, error) {
+			return kitInstance.Extensions().AppendEntry(entryType, data)
+		},
+		GetEntries: func(entryType string) []extensions.ExtensionEntry {
+			return kitInstance.Extensions().GetEntries(entryType)
+		},
+
+		// -------------------------------------------------------------------
+		// Extension state
+		// -------------------------------------------------------------------
+		SetState: func(key string, value string) {
+			kitInstance.Extensions().SetState(key, value)
+		},
+		GetState: func(key string) (string, bool) {
+			return kitInstance.Extensions().GetState(key)
+		},
+		DeleteState: func(key string) {
+			kitInstance.Extensions().DeleteState(key)
+		},
+		ListState: func() []string {
+			return kitInstance.Extensions().ListState()
+		},
+
+		// -------------------------------------------------------------------
+		// Options, model, and tool management
+		// -------------------------------------------------------------------
+		GetOption: func(name string) string {
+			return kitInstance.Extensions().GetOption(name)
+		},
+		SetOption: func(name string, value string) {
+			kitInstance.Extensions().SetOption(name, value)
+		},
+		// Headless model switch. The interactive TUI overrides this with a
+		// version that also notifies the TUI and refreshes the usage tracker.
+		SetModel: func(modelString string) error {
+			previousModel := kitInstance.Extensions().GetContext().Model
+			if err := kitInstance.SetModel(context.Background(), modelString); err != nil {
+				return err
+			}
+			kitInstance.Extensions().UpdateContextModel(modelString)
+			kitInstance.Extensions().EmitModelChange(modelString, previousModel, "extension")
+			return nil
+		},
+		GetAvailableModels: func() []extensions.ModelInfoEntry {
+			return kitInstance.GetAvailableModels()
+		},
+		EmitCustomEvent: func(name string, data string) {
+			kitInstance.Extensions().EmitCustomEvent(name, data)
+		},
+		GetAllTools: func() []extensions.ToolInfo {
+			return kitInstance.Extensions().GetToolInfos()
+		},
+		SetActiveTools: func(names []string) {
+			kitInstance.Extensions().SetActiveTools(names)
+		},
+		// Headless reload. The interactive TUI overrides this to also
+		// refresh widgets/status/commands.
+		ReloadExtensions: func() error {
+			return kitInstance.Extensions().Reload()
+		},
+
+		// -------------------------------------------------------------------
+		// LLM completions and subagents
+		// -------------------------------------------------------------------
+		Complete: func(req extensions.CompleteRequest) (extensions.CompleteResponse, error) {
+			return kitInstance.ExecuteCompletion(context.Background(), req)
+		},
+		SpawnSubagent: func(config extensions.SubagentConfig) (*extensions.SubagentHandle, *extensions.SubagentResult, error) {
+			return SpawnSubagent(ctx, kitInstance, config)
+		},
+
+		// -------------------------------------------------------------------
+		// Tree Navigation API
+		// -------------------------------------------------------------------
+		GetTreeNode: func(entryID string) *extensions.TreeNode {
+			node := kitInstance.GetTreeNode(entryID)
+			if node == nil {
+				return nil
+			}
+			return &extensions.TreeNode{
+				ID:        node.ID,
+				ParentID:  node.ParentID,
+				Type:      node.Type,
+				Role:      node.Role,
+				Content:   node.Content,
+				Model:     node.Model,
+				Provider:  node.Provider,
+				Timestamp: node.Timestamp,
+				Children:  node.Children,
+			}
+		},
+		GetCurrentBranch: func() []extensions.TreeNode {
+			nodes := kitInstance.GetCurrentBranch()
+			result := make([]extensions.TreeNode, len(nodes))
+			for i, n := range nodes {
+				result[i] = extensions.TreeNode{
+					ID:        n.ID,
+					ParentID:  n.ParentID,
+					Type:      n.Type,
+					Role:      n.Role,
+					Content:   n.Content,
+					Model:     n.Model,
+					Provider:  n.Provider,
+					Timestamp: n.Timestamp,
+					Children:  n.Children,
+				}
+			}
+			return result
+		},
+		GetChildren: func(parentID string) []string {
+			return kitInstance.GetChildren(parentID)
+		},
+		NavigateTo: func(entryID string) extensions.TreeNavigationResult {
+			err := kitInstance.NavigateTo(entryID)
+			if err != nil {
+				return extensions.TreeNavigationResult{Success: false, Error: err.Error()}
+			}
+			return extensions.TreeNavigationResult{Success: true}
+		},
+		SummarizeBranch: func(fromID, toID string) string {
+			summary, _ := kitInstance.SummarizeBranch(fromID, toID)
+			return summary
+		},
+		CollapseBranch: func(fromID, toID, summary string) extensions.TreeNavigationResult {
+			err := kitInstance.CollapseBranch(fromID, toID, summary)
+			if err != nil {
+				return extensions.TreeNavigationResult{Success: false, Error: err.Error()}
+			}
+			return extensions.TreeNavigationResult{Success: true}
+		},
+
+		// -------------------------------------------------------------------
+		// Skill Loading API (context-injection variants are TUI-specific and
+		// wired by the interactive overlay)
+		// -------------------------------------------------------------------
+		LoadSkill: func(path string) (*extensions.Skill, string) {
+			s, err := kitInstance.LoadSkillForExtension(path)
+			return s, err
+		},
+		LoadSkillsFromDir: func(dir string) extensions.SkillLoadResult {
+			return kitInstance.LoadSkillsFromDirForExtension(dir)
+		},
+		DiscoverSkills: func() extensions.SkillLoadResult {
+			skills := kitInstance.DiscoverSkillsForExtension()
+			return extensions.SkillLoadResult{Skills: skills}
+		},
+		GetAvailableSkills: func() []extensions.Skill {
+			return kitInstance.DiscoverSkillsForExtension()
+		},
+
+		// -------------------------------------------------------------------
+		// Template Parsing API
+		// -------------------------------------------------------------------
+		ParseTemplate: func(name, content string) extensions.PromptTemplate {
+			return kit.ParseTemplate(name, content)
+		},
+		RenderTemplate: func(tpl extensions.PromptTemplate, vars map[string]string) string {
+			return kit.RenderTemplate(tpl, vars)
+		},
+		ParseArguments: func(input string, pattern extensions.ArgumentPattern) extensions.ParseResult {
+			return kit.ParseArguments(input, pattern)
+		},
+		SimpleParseArguments: func(input string, count int) []string {
+			return kit.SimpleParseArguments(input, count)
+		},
+		EvaluateModelConditional: func(condition string) bool {
+			return kit.EvaluateModelConditional(kitInstance.Extensions().GetContext().Model, condition)
+		},
+		RenderWithModelConditionals: func(content string) string {
+			return kit.RenderWithModelConditionals(content, kitInstance.Extensions().GetContext().Model)
+		},
+
+		// -------------------------------------------------------------------
+		// Model Resolution API
+		// -------------------------------------------------------------------
+		ResolveModelChain: func(preferences []string) extensions.ModelResolutionResult {
+			return kit.ResolveModelChain(preferences)
+		},
+		GetModelCapabilities: func(model string) (extensions.ModelCapabilities, string) {
+			return kit.GetModelCapabilities(model)
+		},
+		CheckModelAvailable: func(model string) bool {
+			return kit.CheckModelAvailable(model)
+		},
+		GetCurrentProvider: func() string {
+			return kit.GetCurrentProvider(kitInstance.Extensions().GetContext().Model)
+		},
+		GetCurrentModelID: func() string {
+			return kit.GetCurrentModelID(kitInstance.Extensions().GetContext().Model)
+		},
+	}
+}

internal/extbridge/extbridge.go

@@ -0,0 +1,98 @@
+// Package extbridge wires the public Kit SDK to the internal extensions
+// package. It exists so that cmd/ and internal/acpserver/ don't both
+// reimplement the same SDK→extension event/subagent conversions.
+package extbridge
+
+import (
+	"context"
+
+	"github.com/mark3labs/kit/internal/extensions"
+	kit "github.com/mark3labs/kit/pkg/kit"
+)
+
+// SDKEventToSubagentEvent converts an SDK [kit.Event] into the
+// extension-facing [extensions.SubagentEvent]. Returns a zero-value event
+// (Type=="") for events that don't map to anything useful — callers should
+// drop those.
+func SDKEventToSubagentEvent(e kit.Event) extensions.SubagentEvent {
+	switch ev := e.(type) {
+	case kit.MessageUpdateEvent:
+		return extensions.SubagentEvent{Type: "text", Content: ev.Chunk}
+	case kit.ReasoningDeltaEvent:
+		return extensions.SubagentEvent{Type: "reasoning", Content: ev.Delta}
+	case kit.ToolCallEvent:
+		return extensions.SubagentEvent{
+			Type: "tool_call", ToolCallID: ev.ToolCallID,
+			ToolName: ev.ToolName, ToolKind: ev.ToolKind, ToolArgs: ev.ToolArgs,
+		}
+	case kit.ToolExecutionStartEvent:
+		return extensions.SubagentEvent{
+			Type: "tool_execution_start", ToolCallID: ev.ToolCallID,
+			ToolName: ev.ToolName, ToolKind: ev.ToolKind,
+		}
+	case kit.ToolExecutionEndEvent:
+		return extensions.SubagentEvent{
+			Type: "tool_execution_end", ToolCallID: ev.ToolCallID,
+			ToolName: ev.ToolName, ToolKind: ev.ToolKind,
+		}
+	case kit.ToolResultEvent:
+		return extensions.SubagentEvent{
+			Type: "tool_result", ToolCallID: ev.ToolCallID,
+			ToolName: ev.ToolName, ToolKind: ev.ToolKind,
+			ToolResult: ev.Result, IsError: ev.IsError,
+		}
+	case kit.TurnStartEvent:
+		return extensions.SubagentEvent{Type: "turn_start"}
+	case kit.TurnEndEvent:
+		return extensions.SubagentEvent{Type: "turn_end"}
+	default:
+		return extensions.SubagentEvent{}
+	}
+}
+
+// SpawnSubagent runs a subagent in-process via the Kit SDK and translates
+// the result/events back into the extension-facing types. The returned
+// handle is always nil — the SDK path runs synchronously and does not
+// expose a separate process handle. Callers that need non-blocking
+// behaviour should run this in their own goroutine.
+//
+// This function consolidates the previously-duplicated wiring in
+// cmd/root.go (interactive + runtime contexts) and
+// internal/acpserver/session.go.
+func SpawnSubagent(ctx context.Context, k *kit.Kit, cfg extensions.SubagentConfig) (*extensions.SubagentHandle, *extensions.SubagentResult, error) {
+	sdkCfg := kit.SubagentConfig{
+		Prompt:       cfg.Prompt,
+		Model:        cfg.Model,
+		SystemPrompt: cfg.SystemPrompt,
+		Timeout:      cfg.Timeout,
+		NoSession:    cfg.NoSession,
+		Tools:        k.GetToolsForSubagent(),
+	}
+	if cfg.OnEvent != nil {
+		sdkCfg.OnEvent = func(e kit.Event) {
+			se := SDKEventToSubagentEvent(e)
+			if se.Type != "" {
+				cfg.OnEvent(se)
+			}
+		}
+	}
+
+	result, err := k.Subagent(ctx, sdkCfg)
+	if result == nil {
+		return nil, &extensions.SubagentResult{Error: err}, err
+	}
+
+	extResult := &extensions.SubagentResult{
+		Response:  result.Response,
+		Error:     err,
+		SessionID: result.SessionID,
+		Elapsed:   result.Elapsed,
+	}
+	if result.Usage != nil {
+		extResult.Usage = &extensions.SubagentUsage{
+			InputTokens:  result.Usage.InputTokens,
+			OutputTokens: result.Usage.OutputTokens,
+		}
+	}
+	return nil, extResult, err
+}

internal/extensions/api.go

@@ -77,6 +77,64 @@ type Context struct {
 	//   ctx.CancelAndSend("Stop what you're doing and focus on the tests")
 	CancelAndSend func(string)
 
+	// Abort cancels the current agent turn (if running) and clears the
+	// message queue. Unlike CancelAndSend, no new message is injected —
+	// the agent simply stops. Safe to call when idle (no-op).
+	//
+	// Example:
+	//
+	//   ctx.Abort()  // stop whatever the agent is doing
+	Abort func()
+
+	// IsIdle returns true when the agent is not processing a turn.
+	// Extensions can use this to decide whether to dispatch immediately
+	// or queue work for later.
+	//
+	// Example:
+	//
+	//   if ctx.IsIdle() {
+	//       ctx.SendMessage("start new task")
+	//   }
+	IsIdle func() bool
+
+	// Compact triggers context compaction, summarising older messages to
+	// free context window space. Returns an error if compaction cannot
+	// start (e.g. agent is busy or app is closed). The actual compaction
+	// runs asynchronously; use OnComplete/OnError callbacks in
+	// CompactConfig to observe the result.
+	//
+	// Example:
+	//
+	//   err := ctx.Compact(ext.CompactConfig{
+	//       OnComplete: func() { ctx.PrintInfo("Compaction done") },
+	//       OnError:    func(errMsg string) { ctx.PrintError("Compact failed: " + errMsg) },
+	//   })
+	Compact func(CompactConfig) error
+
+	// SendMultimodalMessage injects a message with file attachments (images,
+	// documents) into the conversation and triggers a new agent turn. Files
+	// are described by FilePart structs containing the raw bytes, filename,
+	// and MIME type. If the agent is busy the message is queued.
+	//
+	// Example:
+	//
+	//   data, _ := os.ReadFile("photo.jpg")
+	//   ctx.SendMultimodalMessage("Describe this image", []ext.FilePart{
+	//       {Filename: "photo.jpg", Data: data, MediaType: "image/jpeg"},
+	//   })
+	SendMultimodalMessage func(text string, files []FilePart)
+
+	// GetSessionUsage returns aggregated token usage and cost statistics
+	// for the current session. This includes total input/output tokens,
+	// cache read/write tokens, total cost, and request count.
+	//
+	// Example:
+	//
+	//   usage := ctx.GetSessionUsage()
+	//   fmt.Sprintf("Tokens: ↑%d ↓%d Cost: $%.3f",
+	//       usage.TotalInputTokens, usage.TotalOutputTokens, usage.TotalCost)
+	GetSessionUsage func() SessionUsage
+
 	// SetWidget places or updates a persistent widget in the TUI. Widgets
 	// remain visible across agent turns until explicitly removed. The
 	// widget is identified by WidgetConfig.ID; calling SetWidget with the
@@ -283,6 +341,13 @@ type Context struct {
 	// The data survives across session restarts and can be retrieved via
 	// GetEntries. Use entryType to namespace your data (e.g. "myext:state").
 	//
+	// AppendEntry is append-only and lives in the conversation tree, which
+	// makes it the right tool for audit logs and event histories. For
+	// last-write-wins snapshot state — "what's the current value of X?" —
+	// prefer SetState / GetState instead. Those primitives store data in a
+	// sidecar file outside the conversation tree, are O(1) to read/write,
+	// and do not bloat branch reads or duplicate on fork.
+	//
 	// Example:
 	//
 	//   data, _ := json.Marshal(myState)
@@ -302,6 +367,45 @@ type Context struct {
 	//   }
 	GetEntries func(entryType string) []ExtensionEntry
 
+	// SetState stores a key-value pair in session-scoped, last-write-wins
+	// extension state. Unlike AppendEntry the value is kept in a sidecar
+	// file outside the conversation tree, so:
+	//   - reads are O(1) (no branch walk)
+	//   - writes don't bloat the session JSONL
+	//   - state is not duplicated on fork (branches share the sidecar)
+	//   - state is invisible to the LLM
+	//
+	// Use SetState for snapshot state ("current value of X"); use
+	// AppendEntry for audit logs and event histories. Namespace keys with
+	// your extension name to avoid collisions (e.g. "myext:budget-cap").
+	//
+	// State persists for the lifetime of the session. For ephemeral or
+	// in-memory sessions the state lives only in memory.
+	//
+	// Example:
+	//
+	//   ctx.SetState("myext:budget-cap", "10.00")
+	SetState func(key string, value string)
+
+	// GetState returns the value previously stored via SetState. The bool
+	// is false when the key was never written. Returns ("", false) when
+	// state is unavailable.
+	//
+	// Example:
+	//
+	//   if cap, ok := ctx.GetState("myext:budget-cap"); ok {
+	//       fmt.Println("current cap:", cap)
+	//   }
+	GetState func(key string) (string, bool)
+
+	// DeleteState removes a key from session-scoped extension state.
+	// No-op when the key is missing.
+	DeleteState func(key string)
+
+	// ListState returns all keys currently stored in session-scoped
+	// extension state, in unspecified order.
+	ListState func() []string
+
 	// SetEditorText sets the text content of the input editor. This can
 	// be used to pre-fill the editor with suggested text (e.g. extracted
 	// questions, handoff prompts). The cursor is moved to the end.
@@ -572,6 +676,102 @@ type Context struct {
 	//   })
 	//   // handle.Kill() to cancel, handle.Wait() to block
 	SpawnSubagent func(SubagentConfig) (*SubagentHandle, *SubagentResult, error)
+
+	// -------------------------------------------------------------------------
+	// Tree Navigation API (Phase 1 Bridge)
+	// -------------------------------------------------------------------------
+
+	// GetTreeNode returns a node by ID with full metadata and children.
+	// Returns nil if entry not found.
+	GetTreeNode func(entryID string) *TreeNode
+
+	// GetCurrentBranch returns the path from root to current leaf.
+	// Each node contains full metadata (unlike GetMessages which flattens).
+	GetCurrentBranch func() []TreeNode
+
+	// GetChildren returns direct child IDs of an entry.
+	GetChildren func(entryID string) []string
+
+	// NavigateTo branches/forks the session to the specified entry ID.
+	// Equivalent to SDK's Branch() but for extensions.
+	NavigateTo func(entryID string) TreeNavigationResult
+
+	// SummarizeBranch uses LLM to summarize a branch range.
+	// Returns summary text or error string (empty if success).
+	SummarizeBranch func(fromID, toID string) string
+
+	// CollapseBranch replaces a branch range with a summary entry.
+	// This is the "fresh context" primitive for context window management.
+	CollapseBranch func(fromID, toID, summary string) TreeNavigationResult
+
+	// -------------------------------------------------------------------------
+	// Skill Loading API (Phase 2 Bridge)
+	// -------------------------------------------------------------------------
+
+	// LoadSkill loads a single skill file from path.
+	// Parses YAML frontmatter, returns skill with content ready for injection.
+	LoadSkill func(path string) (*Skill, string)
+
+	// LoadSkillsFromDir discovers and loads all skills from a directory.
+	LoadSkillsFromDir func(dir string) SkillLoadResult
+
+	// DiscoverSkills finds skills in standard locations.
+	// Checks ~/.config/kit/skills/, .kit/skills/, .agents/skills/
+	DiscoverSkills func() SkillLoadResult
+
+	// InjectSkillAsContext sends a skill's content as a system message.
+	// Looks up skill by name from discovered skills.
+	InjectSkillAsContext func(skillName string) string
+
+	// InjectRawSkillAsContext loads and immediately injects a skill file.
+	InjectRawSkillAsContext func(path string) string
+
+	// GetAvailableSkills returns all currently loaded/discovered skills.
+	GetAvailableSkills func() []Skill
+
+	// -------------------------------------------------------------------------
+	// Template Parsing API (Phase 3 Bridge)
+	// -------------------------------------------------------------------------
+
+	// ParseTemplate extracts {{variables}} from template content.
+	ParseTemplate func(name, content string) PromptTemplate
+
+	// RenderTemplate substitutes variables into template content.
+	RenderTemplate func(tpl PromptTemplate, vars map[string]string) string
+
+	// ParseArguments parses command-line style arguments.
+	ParseArguments func(input string, pattern ArgumentPattern) ParseResult
+
+	// SimpleParseArguments parses $1, $2, $@ style arguments.
+	// Returns slice where [0]=full input, [1]=$1, [2]=$2, ... [n]=$@
+	SimpleParseArguments func(input string, count int) []string
+
+	// EvaluateModelConditional checks if condition matches current model.
+	// Condition supports wildcards: * matches any, ? matches single char.
+	EvaluateModelConditional func(condition string) bool
+
+	// RenderWithModelConditionals processes <if-model> blocks in content.
+	RenderWithModelConditionals func(content string) string
+
+	// -------------------------------------------------------------------------
+	// Model Resolution API (Phase 4 Bridge)
+	// -------------------------------------------------------------------------
+
+	// ResolveModelChain attempts each model in order until one is available.
+	ResolveModelChain func(preferences []string) ModelResolutionResult
+
+	// GetModelCapabilities returns capabilities for a specific model.
+	// If model is empty, uses current model.
+	GetModelCapabilities func(model string) (ModelCapabilities, string)
+
+	// CheckModelAvailable verifies if a model string is valid.
+	CheckModelAvailable func(model string) bool
+
+	// GetCurrentProvider returns just the provider part of current model.
+	GetCurrentProvider func() string
+
+	// GetCurrentModelID returns just the model ID part of current model.
+	GetCurrentModelID func() string
 }
 
 // ---------------------------------------------------------------------------
@@ -598,6 +798,148 @@ type SessionMessage struct {
 	Timestamp string
 }
 
+// ---------------------------------------------------------------------------
+// Tree navigation types (exposed to Yaegi — concrete structs)
+// ---------------------------------------------------------------------------
+
+// TreeNode represents a node in the session tree for navigation.
+// Extensions use this to traverse conversation history and implement
+// features like "fresh context" loops and branch summarization.
+type TreeNode struct {
+	// ID is the unique entry identifier.
+	ID string
+	// ParentID links this entry to its parent (empty if root).
+	ParentID string
+	// Type is the entry type: "message", "branch_summary", "model_change", "extension_data", "tool_execution".
+	Type string
+	// Role is the message role for message entries: "user", "assistant", "system", "tool".
+	Role string
+	// Content is the text content or summary.
+	Content string
+	// Model is the model that generated this (for assistant messages).
+	Model string
+	// Provider is the provider used.
+	Provider string
+	// Timestamp is the RFC3339-formatted creation time.
+	Timestamp string
+	// Children is the list of child entry IDs for tree traversal.
+	Children []string
+}
+
+// TreeNavigationResult reports success or failure of tree operations.
+type TreeNavigationResult struct {
+	// Success is true if the operation completed.
+	Success bool
+	// Error describes what went wrong (empty if success).
+	Error string
+}
+
+// ---------------------------------------------------------------------------
+// Skill types (exposed to Yaegi — concrete structs)
+// ---------------------------------------------------------------------------
+
+// Skill represents a loaded skill file with parsed YAML frontmatter.
+type Skill struct {
+	// Name is the human-readable identifier.
+	Name string
+	// Description summarizes what this skill provides.
+	Description string
+	// Content is the markdown body (frontmatter stripped).
+	Content string
+	// Path is the absolute filesystem path.
+	Path string
+	// Tags are optional labels for categorization.
+	Tags []string
+	// When controls automatic inclusion: "always", "on-demand", or file-glob.
+	When string
+}
+
+// SkillLoadResult reports skills loaded from a directory.
+type SkillLoadResult struct {
+	// Skills is the list of loaded skills.
+	Skills []Skill
+	// Error describes loading failures (empty if success).
+	Error string
+}
+
+// ---------------------------------------------------------------------------
+// Template parsing types (exposed to Yaegi — concrete structs)
+// ---------------------------------------------------------------------------
+
+// PromptTemplate represents a parsed template with variable placeholders.
+type PromptTemplate struct {
+	// Name is the template identifier.
+	Name string
+	// Content is the original template content.
+	Content string
+	// Variables are the extracted {{variable}} names.
+	Variables []string
+}
+
+// ArgumentPattern defines how to parse command arguments.
+type ArgumentPattern struct {
+	// Positional names for $1, $2, etc.
+	Positional []string
+	// Rest is the variable name for $@ (all remaining).
+	Rest string
+	// Flags maps flag names to variable names (e.g., "--loop" -> "loop").
+	Flags map[string]string
+}
+
+// ParseResult reports argument parsing outcome.
+type ParseResult struct {
+	// Vars maps variable names to values for positional args.
+	Vars map[string]string
+	// Flags maps flag names to values.
+	Flags map[string]string
+	// Rest is remaining unparsed text.
+	Rest string
+	// Error describes parsing failures (empty if success).
+	Error string
+}
+
+// ModelConditional represents an <if-model> block for evaluation.
+type ModelConditional struct {
+	// Condition is the model pattern (e.g., "claude-*", "anthropic/*").
+	Condition string
+	// Content is rendered if condition matches.
+	Content string
+	// Else is rendered if condition doesn't match.
+	Else string
+}
+
+// ---------------------------------------------------------------------------
+// Model resolution types (exposed to Yaegi — concrete structs)
+// ---------------------------------------------------------------------------
+
+// ModelCapabilities describes what a model supports.
+type ModelCapabilities struct {
+	// Provider is the provider ID (e.g., "anthropic").
+	Provider string
+	// ModelID is the model identifier (e.g., "claude-sonnet-4-20250929").
+	ModelID string
+	// ContextLimit is the maximum context window in tokens.
+	ContextLimit int
+	// OutputLimit is the maximum output tokens.
+	OutputLimit int
+	// Reasoning indicates if the model supports reasoning/thinking.
+	Reasoning bool
+	// Streaming indicates if the model supports streaming.
+	Streaming bool
+}
+
+// ModelResolutionResult reports model chain resolution outcome.
+type ModelResolutionResult struct {
+	// Model is the selected model in "provider/model" format.
+	Model string
+	// Capabilities describes the selected model.
+	Capabilities ModelCapabilities
+	// Attempted lists models tried before success.
+	Attempted []string
+	// Error describes resolution failures (empty if success).
+	Error string
+}
+
 // ExtensionEntry represents persisted extension data stored in the session.
 // Extensions use AppendEntry to save custom state and GetEntries to retrieve
 // it on session resume.
@@ -622,7 +964,7 @@ type ExtensionEntry struct {
 type ContextMessage struct {
 	// Index is the position of this message in the original context array
 	// (0-based). When returning messages from a ContextPrepareResult,
-	// messages with Index >= 0 reuse the original fantasy.Message at that
+	// messages with Index >= 0 reuse the original LLM message at that
 	// position (preserving tool calls, reasoning, and other complex parts).
 	// Set Index to -1 for newly injected messages (created from Role + Content).
 	Index int
@@ -699,6 +1041,48 @@ type StatusBarEntry struct {
 	Priority int
 }
 
+// CompactConfig configures a programmatic context compaction request.
+type CompactConfig struct {
+	// CustomInstructions is optional text appended to the summary prompt
+	// (e.g. "Focus on the API design decisions"). Empty uses the default.
+	CustomInstructions string
+	// OnComplete is called when compaction finishes successfully.
+	// May be nil if the caller doesn't need notification.
+	OnComplete func()
+	// OnError is called when compaction fails. The argument is the error message.
+	// May be nil if the caller doesn't need notification.
+	OnError func(errMsg string)
+}
+
+// FilePart describes a file attachment for multimodal messages. Extensions
+// use this with SendMultimodalMessage to attach images or documents.
+type FilePart struct {
+	// Filename is the name of the file (e.g. "photo.jpg").
+	Filename string
+	// Data is the raw file content.
+	Data []byte
+	// MediaType is the MIME type (e.g. "image/jpeg", "application/pdf").
+	MediaType string
+}
+
+// SessionUsage contains aggregated token usage and cost statistics for
+// the current session. Extensions use this with GetSessionUsage() to
+// report usage information.
+type SessionUsage struct {
+	// TotalInputTokens is the sum of input tokens across all requests.
+	TotalInputTokens int
+	// TotalOutputTokens is the sum of output tokens across all requests.
+	TotalOutputTokens int
+	// TotalCacheReadTokens is the sum of cache read tokens.
+	TotalCacheReadTokens int
+	// TotalCacheWriteTokens is the sum of cache write tokens.
+	TotalCacheWriteTokens int
+	// TotalCost is the total cost in USD across all requests.
+	TotalCost float64
+	// RequestCount is the number of LLM requests made in this session.
+	RequestCount int
+}
+
 // PrintBlockOpts configures a custom styled block for PrintBlock.
 type PrintBlockOpts struct {
 	// Text is the main content to display.
@@ -725,6 +1109,9 @@ type PrintBlockOpts struct {
 type API struct {
 	// Event-specific registration functions (wired by the loader).
 	onToolCall                func(func(ToolCallEvent, Context) *ToolCallResult)
+	onToolCallInputStart      func(func(ToolCallInputStartEvent, Context))
+	onToolCallInputDelta      func(func(ToolCallInputDeltaEvent, Context))
+	onToolCallInputEnd        func(func(ToolCallInputEndEvent, Context))
 	onToolExecStart           func(func(ToolExecutionStartEvent, Context))
 	onToolExecEnd             func(func(ToolExecutionEndEvent, Context))
 	onToolOutput              func(func(ToolOutputEvent, Context))
@@ -750,6 +1137,18 @@ type API struct {
 	registerOption            func(OptionDef)
 	registerShortcutFn        func(ShortcutDef, func(Context))
 	registerMessageRendererFn func(MessageRendererConfig)
+	onSubagentStart           func(func(SubagentStartEvent, Context))
+	onSubagentChunk           func(func(SubagentChunkEvent, Context))
+	onSubagentEnd             func(func(SubagentEndEvent, Context))
+	onStepStart               func(func(StepStartEvent, Context))
+	onStepFinish              func(func(StepFinishEvent, Context))
+	onReasoningStart          func(func(ReasoningStartEvent, Context))
+	onWarnings                func(func(WarningsEvent, Context))
+	onSource                  func(func(SourceEvent, Context))
+	onError                   func(func(ErrorEvent, Context))
+	onRetry                   func(func(RetryEvent, Context))
+	onPrepareStep             func(func(PrepareStepEvent, Context) *PrepareStepResult)
+	onLLMUsage                func(func(LLMUsageEvent, Context))
 }
 
 // OnToolCall registers a handler that fires before a tool executes.
@@ -758,6 +1157,26 @@ func (a *API) OnToolCall(handler func(ToolCallEvent, Context) *ToolCallResult) {
 	a.onToolCall(handler)
 }
 
+// OnToolCallInputStart registers a handler that fires when the LLM begins
+// generating tool call arguments. The tool name is known but the full
+// argument JSON is still being streamed. Useful for showing a "running"
+// indicator immediately without waiting for the full arguments.
+func (a *API) OnToolCallInputStart(handler func(ToolCallInputStartEvent, Context)) {
+	a.onToolCallInputStart(handler)
+}
+
+// OnToolCallInputDelta registers a handler that fires for each streamed
+// fragment of tool call arguments as they arrive from the LLM.
+func (a *API) OnToolCallInputDelta(handler func(ToolCallInputDeltaEvent, Context)) {
+	a.onToolCallInputDelta(handler)
+}
+
+// OnToolCallInputEnd registers a handler that fires when tool argument
+// streaming is complete, before the tool call is parsed and execution begins.
+func (a *API) OnToolCallInputEnd(handler func(ToolCallInputEndEvent, Context)) {
+	a.onToolCallInputEnd(handler)
+}
+
 // OnToolExecutionStart registers a handler for tool execution start.
 func (a *API) OnToolExecutionStart(handler func(ToolExecutionStartEvent, Context)) {
 	a.onToolExecStart(handler)
@@ -781,6 +1200,27 @@ func (a *API) OnToolResult(handler func(ToolResultEvent, Context) *ToolResultRes
 	a.onToolResult(handler)
 }
 
+// OnSubagentStart registers a handler that fires when a subagent tool
+// call begins executing. Use the ToolCallID to correlate with subsequent
+// OnSubagentChunk and OnSubagentEnd events for the same subagent.
+func (a *API) OnSubagentStart(handler func(SubagentStartEvent, Context)) {
+	a.onSubagentStart(handler)
+}
+
+// OnSubagentChunk registers a handler for real-time events from a running
+// subagent. ChunkType identifies the kind of event ("text", "tool_call",
+// "tool_result", "tool_execution_start", "tool_execution_end", etc.).
+// Correlate with OnSubagentStart via the ToolCallID field.
+func (a *API) OnSubagentChunk(handler func(SubagentChunkEvent, Context)) {
+	a.onSubagentChunk(handler)
+}
+
+// OnSubagentEnd registers a handler that fires when a subagent call
+// completes. ErrorMsg is non-empty when the subagent failed.
+func (a *API) OnSubagentEnd(handler func(SubagentEndEvent, Context)) {
+	a.onSubagentEnd(handler)
+}
+
 // OnInput registers a handler that fires when user input is received.
 // Return a non-nil InputResult to transform or handle the input.
 func (a *API) OnInput(handler func(InputEvent, Context) *InputResult) {
@@ -916,6 +1356,69 @@ func (a *API) OnBeforeCompact(handler func(BeforeCompactEvent, Context) *BeforeC
 	a.onBeforeCompact(handler)
 }
 
+// OnStepStart registers a handler that fires when a new LLM call begins
+// within a multi-step agent turn.
+func (a *API) OnStepStart(handler func(StepStartEvent, Context)) {
+	a.onStepStart(handler)
+}
+
+// OnStepFinish registers a handler that fires when a step completes,
+// providing step number, finish reason, and decomposed token usage.
+func (a *API) OnStepFinish(handler func(StepFinishEvent, Context)) {
+	a.onStepFinish(handler)
+}
+
+// OnReasoningStart registers a handler that fires when the LLM begins
+// reasoning/thinking.
+func (a *API) OnReasoningStart(handler func(ReasoningStartEvent, Context)) {
+	a.onReasoningStart(handler)
+}
+
+// OnWarnings registers a handler that fires when the LLM provider returns
+// warnings about the request.
+func (a *API) OnWarnings(handler func(WarningsEvent, Context)) {
+	a.onWarnings(handler)
+}
+
+// OnSource registers a handler that fires when the LLM references a source
+// (e.g. from web search tools).
+func (a *API) OnSource(handler func(SourceEvent, Context)) {
+	a.onSource(handler)
+}
+
+// OnError registers a handler that fires when an agent-level error occurs
+// during streaming.
+func (a *API) OnError(handler func(ErrorEvent, Context)) {
+	a.onError(handler)
+}
+
+// OnRetry registers a handler that fires when the LLM provider request is
+// retried after a transient error.
+func (a *API) OnRetry(handler func(RetryEvent, Context)) {
+	a.onRetry(handler)
+}
+
+// OnPrepareStep registers a handler that fires between steps within a
+// multi-step agent turn, after steering messages are injected and before
+// messages are sent to the LLM. Return a non-nil PrepareStepResult with
+// Messages to replace the context window for this step.
+func (a *API) OnPrepareStep(handler func(PrepareStepEvent, Context) *PrepareStepResult) {
+	a.onPrepareStep(handler)
+}
+
+// OnLLMUsage registers a handler that fires after each LLM provider call
+// with the token and cost deltas for that single call. Use this for
+// per-call usage attribution, real-time budget enforcement, and cost
+// dashboards that need to react between calls within a single agent turn.
+//
+// Handlers receive an LLMUsageEvent describing the call's input/output
+// tokens, cache tokens, computed cost, model, and provider. A single agent
+// turn typically fires multiple LLMUsageEvents (one per tool-loop
+// iteration).
+func (a *API) OnLLMUsage(handler func(LLMUsageEvent, Context)) {
+	a.onLLMUsage(handler)
+}
+
 // RegisterToolRenderer registers a custom renderer for a specific tool's
 // display in the TUI. The renderer controls the header (parameter summary)
 // and/or body (result display) of the tool's output block. If multiple
@@ -1528,6 +2031,34 @@ type ToolCallResult struct {
 
 func (ToolCallResult) isResult() {}
 
+// ToolCallInputStartEvent fires when the LLM begins generating tool call
+// arguments. The tool name is known but the full argument JSON is still
+// being streamed.
+type ToolCallInputStartEvent struct {
+	ToolCallID string
+	ToolName   string
+	ToolKind   string // Tool classification: "execute", "edit", "read", "search", "agent"
+}
+
+func (e ToolCallInputStartEvent) Type() EventType { return ToolCallInputStart }
+
+// ToolCallInputDeltaEvent fires for each streamed fragment of tool call
+// arguments as they arrive from the LLM.
+type ToolCallInputDeltaEvent struct {
+	ToolCallID string
+	Delta      string // JSON fragment of tool arguments
+}
+
+func (e ToolCallInputDeltaEvent) Type() EventType { return ToolCallInputDelta }
+
+// ToolCallInputEndEvent fires when tool argument streaming is complete,
+// before the tool call is parsed and execution begins.
+type ToolCallInputEndEvent struct {
+	ToolCallID string
+}
+
+func (e ToolCallInputEndEvent) Type() EventType { return ToolCallInputEnd }
+
 // ToolExecutionStartEvent fires when a tool begins executing.
 type ToolExecutionStartEvent struct {
 	ToolCallID string
@@ -1620,10 +2151,47 @@ type AgentStartEvent struct {
 
 func (e AgentStartEvent) Type() EventType { return AgentStart }
 
-// AgentEndEvent fires when the agent finishes responding.
+// AgentEndEvent fires when the agent finishes responding. In addition to the
+// final response and stop reason, the event carries per-turn aggregates so
+// observer-style extensions don't have to maintain parallel bookkeeping in
+// OnToolResult / OnStepFinish handlers.
 type AgentEndEvent struct {
 	Response   string
 	StopReason string // "completed", "cancelled", "error"
+
+	// ToolCallCount is the total number of tool invocations observed during
+	// this turn (sum across all steps).
+	ToolCallCount int
+
+	// ToolNames lists the tool names invoked during this turn, in call order.
+	// Duplicates are preserved (e.g. two bash calls produce ["bash", "bash"]).
+	ToolNames []string
+
+	// LLMCallCount is the number of LLM round-trips (tool-loop iterations)
+	// performed during this turn. Always >= 1 for a successful turn.
+	LLMCallCount int
+
+	// InputTokensDelta is the sum of input tokens consumed during this turn
+	// across every LLM call (including cache-hit input tokens).
+	InputTokensDelta int
+
+	// OutputTokensDelta is the sum of output tokens generated during this turn.
+	OutputTokensDelta int
+
+	// CacheReadTokensDelta is the sum of cache-read tokens during this turn.
+	CacheReadTokensDelta int
+
+	// CacheWriteTokensDelta is the sum of cache-write tokens during this turn.
+	CacheWriteTokensDelta int
+
+	// CostDelta is the total cost in USD attributable to this turn. Computed
+	// from per-step usage and current model pricing. Zero when pricing is
+	// unknown or OAuth credentials are in use.
+	CostDelta float64
+
+	// DurationMs is the elapsed wall-clock time from AgentStart to AgentEnd,
+	// in milliseconds.
+	DurationMs int64
 }
 
 func (e AgentEndEvent) Type() EventType { return AgentEnd }
@@ -1781,9 +2349,194 @@ type BeforeCompactResult struct {
 func (BeforeCompactResult) isResult() {}
 
 // ---------------------------------------------------------------------------
-// Theme types (exposed to Yaegi — concrete structs, string hex colors)
+// Subagent lifecycle events (exposed to Yaegi — concrete structs)
 // ---------------------------------------------------------------------------
 
+// SubagentStartEvent fires when a subagent tool call begins executing.
+type SubagentStartEvent struct {
+	// ToolCallID is the LLM-assigned ID of the subagent tool call.
+	// Use this to correlate SubagentChunkEvent and SubagentEndEvent.
+	ToolCallID string
+	// Task is the task description passed to the subagent.
+	Task string
+}
+
+func (e SubagentStartEvent) Type() EventType { return SubagentStart }
+
+// SubagentChunkEvent fires for each real-time event from a running subagent.
+// Type field indicates the kind of event; read the relevant fields accordingly.
+type SubagentChunkEvent struct {
+	// ToolCallID matches the SubagentStartEvent.ToolCallID for this subagent.
+	ToolCallID string
+	// Task is the task description (repeated for convenience).
+	Task string
+	// ChunkType identifies the event kind:
+	//   "text"                 — LLM text chunk (read Content)
+	//   "reasoning"            — reasoning/thinking delta (read Content)
+	//   "tool_call"            — subagent called a tool (read ToolName, ToolArgs)
+	//   "tool_result"          — tool returned a result (read ToolName, ToolResult, IsError)
+	//   "tool_execution_start" — tool began executing (read ToolName)
+	//   "tool_execution_end"   — tool finished executing (read ToolName)
+	//   "turn_start"           — subagent turn began
+	//   "turn_end"             — subagent turn ended
+	ChunkType string
+	// Content carries text for "text" and "reasoning" chunk types.
+	Content string
+	// ToolName is set on tool-related chunk types.
+	ToolName string
+	// ToolArgs is the JSON-encoded tool arguments for "tool_call" chunks.
+	ToolArgs string
+	// ToolResult is the tool output for "tool_result" chunks.
+	ToolResult string
+	// IsError is true when a "tool_result" chunk represents an error.
+	IsError bool
+}
+
+func (e SubagentChunkEvent) Type() EventType { return SubagentChunk }
+
+// SubagentEndEvent fires when a subagent tool call completes.
+type SubagentEndEvent struct {
+	// ToolCallID matches the SubagentStartEvent.ToolCallID for this subagent.
+	ToolCallID string
+	// Task is the task description.
+	Task string
+	// Response is the subagent's final text response (empty on error).
+	Response string
+	// ErrorMsg is non-empty when the subagent failed.
+	ErrorMsg string
+}
+
+func (e SubagentEndEvent) Type() EventType { return SubagentEnd }
+
+// ---------------------------------------------------------------------------
+// Step lifecycle events (exposed to Yaegi — concrete structs)
+// ---------------------------------------------------------------------------
+
+// StepStartEvent fires when a new LLM call begins within a multi-step agent turn.
+type StepStartEvent struct {
+	StepNumber int
+}
+
+func (e StepStartEvent) Type() EventType { return StepStart }
+
+// StepFinishEvent fires when a step completes, providing step metadata and
+// token usage. Usage fields are plain int64 (not LLMUsage) because Yaegi
+// cannot handle fantasy types across the interpreter boundary.
+type StepFinishEvent struct {
+	StepNumber       int
+	HasToolCalls     bool
+	FinishReason     string
+	InputTokens      int64
+	OutputTokens     int64
+	CacheReadTokens  int64
+	CacheWriteTokens int64
+}
+
+func (e StepFinishEvent) Type() EventType { return StepFinish }
+
+// ReasoningStartEvent fires when the LLM begins reasoning/thinking.
+type ReasoningStartEvent struct {
+	ID string
+}
+
+func (e ReasoningStartEvent) Type() EventType { return ReasoningStart }
+
+// WarningsEvent fires when the LLM provider returns warnings about the request.
+type WarningsEvent struct {
+	Warnings []string
+}
+
+func (e WarningsEvent) Type() EventType { return Warnings }
+
+// SourceEvent fires when the LLM references a source (e.g. from web search).
+type SourceEvent struct {
+	SourceType string
+	ID         string
+	URL        string
+	Title      string
+}
+
+func (e SourceEvent) Type() EventType { return Source }
+
+// ErrorEvent fires when an agent-level error occurs during streaming.
+// Uses string instead of error because Yaegi cannot handle the error
+// interface reliably across the interpreter boundary.
+type ErrorEvent struct {
+	Error string
+}
+
+func (e ErrorEvent) Type() EventType { return Error }
+
+// RetryEvent fires when the LLM provider request is retried after a
+// transient error.
+type RetryEvent struct {
+	Attempt int
+	Error   string
+}
+
+func (e RetryEvent) Type() EventType { return Retry }
+
+// PrepareStepEvent fires between steps within a multi-step agent turn,
+// after steering messages are injected and before messages are sent to
+// the LLM. Handlers can inspect and replace the context window.
+type PrepareStepEvent struct {
+	// StepNumber is the zero-based step index within the current turn.
+	StepNumber int
+	// Messages is the current context window that will be sent to the LLM.
+	Messages []ContextMessage
+}
+
+func (e PrepareStepEvent) Type() EventType { return PrepareStep }
+
+// PrepareStepResult allows extensions to replace the context window between
+// steps. Return nil Messages to leave the context unchanged.
+type PrepareStepResult struct {
+	// Messages replaces the entire context window for this step. If nil,
+	// the original messages are used unchanged. Messages with a non-negative
+	// Index reuse the original message at that position; messages with
+	// Index < 0 are created fresh from Role + Content.
+	Messages []ContextMessage
+}
+
+func (PrepareStepResult) isResult() {}
+
+// LLMUsageEvent fires after each LLM provider call with the per-call token
+// and cost deltas. Use this for accurate budget tracking, cost dashboards,
+// and any logic that needs to react between LLM calls within a single agent
+// turn (rather than only at turn boundaries).
+//
+// A single agent turn typically produces multiple LLMUsageEvents (one per
+// tool-loop iteration). The Model and Provider fields reflect the model used
+// for that specific call, which may differ from earlier calls if the
+// extension switched models mid-turn via ctx.SetModel().
+type LLMUsageEvent struct {
+	// InputTokens is the number of input tokens for this call.
+	InputTokens int
+	// OutputTokens is the number of output tokens generated by this call.
+	OutputTokens int
+	// CacheReadTokens is the number of cache-hit input tokens (provider-specific).
+	CacheReadTokens int
+	// CacheWriteTokens is the number of cache-write tokens.
+	CacheWriteTokens int
+	// Cost is the USD cost of this call computed from the model's per-token
+	// pricing. Zero when pricing is unknown or OAuth credentials are in use.
+	Cost float64
+	// Model is the model identifier used for this call (e.g. "claude-sonnet-4-5-20250929").
+	Model string
+	// Provider is the provider identifier (e.g. "anthropic", "openai").
+	Provider string
+	// RequestID is an optional correlation id for the underlying provider
+	// call. May be empty when the provider does not surface one.
+	RequestID string
+	// StepNumber is the zero-based step index within the current agent turn.
+	StepNumber int
+	// FinishReason mirrors the provider's finish reason for this call
+	// (e.g. "stop", "tool_calls", "length"). May be empty.
+	FinishReason string
+}
+
+func (e LLMUsageEvent) Type() EventType { return LLMUsage }
+
 // ThemeColor is an adaptive color pair with light and dark hex values.
 // Either field may be empty to inherit from the default theme.
 type ThemeColor struct {

internal/extensions/events.go

@@ -13,6 +13,19 @@ const (
 	// ToolCall fires before a tool executes. Handlers can block execution.
 	ToolCall EventType = "tool_call"
 
+	// ToolCallInputStart fires when the LLM begins generating tool call
+	// arguments. The tool name is known but the full argument JSON is still
+	// being streamed.
+	ToolCallInputStart EventType = "tool_call_input_start"
+
+	// ToolCallInputDelta fires for each streamed fragment of tool call
+	// arguments as they arrive from the LLM.
+	ToolCallInputDelta EventType = "tool_call_input_delta"
+
+	// ToolCallInputEnd fires when tool argument streaming is complete,
+	// before the tool call is parsed and execution begins.
+	ToolCallInputEnd EventType = "tool_call_input_end"
+
 	// ToolExecutionStart fires when a tool begins executing.
 	ToolExecutionStart EventType = "tool_execution_start"
 
@@ -71,17 +84,67 @@ const (
 	// BeforeCompact fires before context compaction runs. Handlers can
 	// cancel compaction by returning Cancel=true.
 	BeforeCompact EventType = "before_compact"
+
+	// SubagentStart fires when a subagent tool call begins executing.
+	// Carries the tool call ID and the task description.
+	SubagentStart EventType = "subagent_start"
+
+	// SubagentChunk fires for each real-time event emitted by a running
+	// subagent: text chunks, tool calls, tool results, etc.
+	SubagentChunk EventType = "subagent_chunk"
+
+	// SubagentEnd fires when a subagent tool call completes (success
+	// or error). Carries the final response and any error message.
+	SubagentEnd EventType = "subagent_end"
+
+	// StepStart fires when a new LLM call begins within a multi-step
+	// agent turn.
+	StepStart EventType = "step_start"
+
+	// StepFinish fires when a step completes, providing step number,
+	// finish reason, and token usage.
+	StepFinish EventType = "step_finish"
+
+	// ReasoningStart fires when the LLM begins reasoning/thinking.
+	ReasoningStart EventType = "reasoning_start"
+
+	// Warnings fires when the LLM provider returns warnings.
+	Warnings EventType = "warnings"
+
+	// Source fires when the LLM references a source (e.g. web search).
+	Source EventType = "source"
+
+	// Error fires when an agent-level error occurs during streaming.
+	Error EventType = "error"
+
+	// Retry fires when the LLM provider request is retried after a
+	// transient error.
+	Retry EventType = "retry"
+
+	// PrepareStep fires between steps within a multi-step agent turn,
+	// after steering messages are injected and before messages are sent
+	// to the LLM. Handlers can replace the context window for this step.
+	PrepareStep EventType = "prepare_step"
+
+	// LLMUsage fires after each LLM provider call with the token and cost
+	// deltas for that single call. Extensions use it to attribute usage to
+	// specific calls/models and to drive budget enforcement between calls.
+	LLMUsage EventType = "llm_usage"
 )
 
 // AllEventTypes returns every supported event type.
 func AllEventTypes() []EventType {
 	return []EventType{
-		ToolCall, ToolExecutionStart, ToolExecutionEnd, ToolResult,
+		ToolCall, ToolCallInputStart, ToolCallInputDelta, ToolCallInputEnd,
+		ToolExecutionStart, ToolExecutionEnd, ToolResult,
 		Input, BeforeAgentStart, AgentStart, AgentEnd,
 		MessageStart, MessageUpdate, MessageEnd,
 		SessionStart, SessionShutdown,
 		ModelChange, ContextPrepare,
 		BeforeFork, BeforeSessionSwitch, BeforeCompact,
+		SubagentStart, SubagentChunk, SubagentEnd,
+		StepStart, StepFinish, ReasoningStart, Warnings, Source, Error, Retry,
+		PrepareStep, LLMUsage,
 	}
 }
 

internal/extensions/events_test.go

@@ -4,8 +4,8 @@ import "testing"
 
 func TestAllEventTypes_Count(t *testing.T) {
 	all := AllEventTypes()
-	if len(all) != 18 {
-		t.Fatalf("expected 18 event types, got %d", len(all))
+	if len(all) != 33 {
+		t.Fatalf("expected 33 event types, got %d", len(all))
 	}
 }
 
@@ -38,6 +38,9 @@ func TestEventType_TypeMethod(t *testing.T) {
 		want  EventType
 	}{
 		{ToolCallEvent{ToolName: "test"}, ToolCall},
+		{ToolCallInputStartEvent{ToolCallID: "x", ToolName: "test"}, ToolCallInputStart},
+		{ToolCallInputDeltaEvent{ToolCallID: "x", Delta: "{"}, ToolCallInputDelta},
+		{ToolCallInputEndEvent{ToolCallID: "x"}, ToolCallInputEnd},
 		{ToolExecutionStartEvent{ToolName: "test"}, ToolExecutionStart},
 		{ToolExecutionEndEvent{ToolName: "test"}, ToolExecutionEnd},
 		{ToolResultEvent{ToolName: "test"}, ToolResult},
@@ -55,6 +58,9 @@ func TestEventType_TypeMethod(t *testing.T) {
 		{BeforeForkEvent{TargetID: "abc"}, BeforeFork},
 		{BeforeSessionSwitchEvent{Reason: "new"}, BeforeSessionSwitch},
 		{BeforeCompactEvent{EstimatedTokens: 1000}, BeforeCompact},
+		{SubagentStartEvent{ToolCallID: "x", Task: "t"}, SubagentStart},
+		{SubagentChunkEvent{ToolCallID: "x", ChunkType: "text"}, SubagentChunk},
+		{SubagentEndEvent{ToolCallID: "x"}, SubagentEnd},
 	}
 
 	for _, tt := range tests {

internal/extensions/installer.go

@@ -154,6 +154,11 @@ func NewInstaller(projectDir string) *Installer {
 
 // Install clones a git repository to the appropriate scope.
 func (i *Installer) Install(source *GitSource, scope InstallScope) error {
+	return i.install(source, scope, nil)
+}
+
+// install is the internal implementation that supports optional include paths.
+func (i *Installer) install(source *GitSource, scope InstallScope, includePaths []string) error {
 	targetDir := i.getInstallPath(source, scope)
 
 	// Check if already installed
@@ -199,6 +204,7 @@ func (i *Installer) Install(source *GitSource, scope InstallScope) error {
 		Pinned:    source.Pinned,
 		Scope:     scope,
 		Installed: time.Now(),
+		Include:   includePaths,
 	}
 	if err := i.addToManifest(entry, scope); err != nil {
 		// Don't fail the install, just log the error
@@ -268,7 +274,22 @@ func (i *Installer) Update(source *GitSource, scope InstallScope) error {
 	cleanCmd.Dir = targetDir
 	_ = cleanCmd.Run() // Ignore errors - clean is best effort
 
-	// Update manifest timestamp
+	// Update manifest timestamp, preserving existing fields like Include
+	existing, _ := i.loadManifest(scope)
+	var include []string
+	var installed time.Time
+	if existing != nil {
+		for _, p := range existing.Packages {
+			if p.Host+"/"+p.Path == source.Identity() {
+				include = p.Include
+				installed = p.Installed
+				break
+			}
+		}
+	}
+	if installed.IsZero() {
+		installed = time.Now()
+	}
 	entry := ManifestEntry{
 		Source:    source.String(),
 		Repo:      source.Repo,
@@ -277,8 +298,9 @@ func (i *Installer) Update(source *GitSource, scope InstallScope) error {
 		Ref:       "",
 		Pinned:    false,
 		Scope:     scope,
-		Installed: time.Now(),
+		Installed: installed,
 		Updated:   time.Now(),
+		Include:   include,
 	}
 	_ = i.addToManifest(entry, scope) // Best effort - don't fail update if manifest fails
 
@@ -428,25 +450,6 @@ func globalGitInstallRoot() string {
 	return filepath.Join(base, "kit", "git")
 }
 
-// GetInstalledPackages returns all installed packages from both scopes.
-func (i *Installer) GetInstalledPackages() ([]ManifestEntry, error) {
-	var all []ManifestEntry
-
-	global, err := i.loadManifest(ScopeGlobal)
-	if err != nil {
-		return nil, fmt.Errorf("loading global manifest: %w", err)
-	}
-	all = append(all, global.Packages...)
-
-	project, err := i.loadManifest(ScopeProject)
-	if err != nil {
-		return nil, fmt.Errorf("loading project manifest: %w", err)
-	}
-	all = append(all, project.Packages...)
-
-	return all, nil
-}
-
 // IsInstalled checks if a package is installed in either scope.
 // Returns (scope, true) if installed, ("", false) otherwise.
 func (i *Installer) IsInstalled(source *GitSource) (InstallScope, bool) {
@@ -503,30 +506,7 @@ func (i *Installer) PreviewExtensions(source *GitSource) ([]ExtensionPreview, st
 // InstallWithInclude clones a repo and installs only the specified extensions.
 // includePaths are relative paths like "./git/main.go" - if empty, installs all.
 func (i *Installer) InstallWithInclude(source *GitSource, scope InstallScope, includePaths []string) error {
-	// First, do a regular install
-	if err := i.Install(source, scope); err != nil {
-		return err
-	}
-
-	// If specific includes were requested, update the manifest
-	if len(includePaths) > 0 {
-		entry := ManifestEntry{
-			Source:  source.String(),
-			Repo:    source.Repo,
-			Host:    source.Host,
-			Path:    source.Path,
-			Ref:     source.Ref,
-			Pinned:  source.Pinned,
-			Scope:   scope,
-			Include: includePaths,
-		}
-
-		if err := addEntryToManifest(entry, scope); err != nil {
-			return fmt.Errorf("updating manifest with includes: %w", err)
-		}
-	}
-
-	return nil
+	return i.install(source, scope, includePaths)
 }
 
 // CleanupTempDir removes a temporary directory used for preview.

internal/extensions/installer_test.go

@@ -245,14 +245,21 @@ func TestManifestEntryIdentity(t *testing.T) {
 	}
 }
 
+// TestLoadAndSaveManifest exercises the live *Installer.loadManifest /
+// saveManifest round-trip against a temp directory, ensuring an absent
+// manifest loads as empty and a saved manifest reads back identically.
 func TestLoadAndSaveManifest(t *testing.T) {
 	tempDir := t.TempDir()
+	installer := &Installer{
+		projectGitRoot: tempDir,
+		globalGitRoot:  tempDir,
+	}
 	manifestPath := filepath.Join(tempDir, "packages.json")
 
 	// Test loading non-existent manifest
-	manifest, err := loadManifestFromPath(manifestPath)
+	manifest, err := installer.loadManifest(ScopeGlobal)
 	if err != nil {
-		t.Fatalf("loadManifestFromPath() error = %v", err)
+		t.Fatalf("loadManifest() error = %v", err)
 	}
 	if len(manifest.Packages) != 0 {
 		t.Errorf("Expected empty packages, got %d", len(manifest.Packages))
@@ -273,15 +280,20 @@ func TestLoadAndSaveManifest(t *testing.T) {
 	}
 
 	// Save it
-	err = saveManifestToPath(manifest, manifestPath)
+	err = installer.saveManifest(manifest, ScopeGlobal)
 	if err != nil {
-		t.Fatalf("saveManifestToPath() error = %v", err)
+		t.Fatalf("saveManifest() error = %v", err)
+	}
+
+	// Verify it was written to expected path
+	if _, err := os.Stat(manifestPath); err != nil {
+		t.Fatalf("manifest file not created: %v", err)
 	}
 
 	// Load it back
-	loaded, err := loadManifestFromPath(manifestPath)
+	loaded, err := installer.loadManifest(ScopeGlobal)
 	if err != nil {
-		t.Fatalf("loadManifestFromPath() error = %v", err)
+		t.Fatalf("loadManifest() error = %v", err)
 	}
 	if len(loaded.Packages) != 1 {
 		t.Errorf("Expected 1 package, got %d", len(loaded.Packages))
@@ -291,21 +303,15 @@ func TestLoadAndSaveManifest(t *testing.T) {
 	}
 }
 
+// TestAddAndRemoveFromManifest verifies that *Installer.addToManifest
+// followed by removeFromManifest leaves the manifest in its original
+// (empty) state, using a temp-directory installer scope.
 func TestAddAndRemoveFromManifest(t *testing.T) {
 	tempDir := t.TempDir()
-
-	// Set up environment for manifest path
-	if err := os.Setenv("XDG_DATA_HOME", tempDir); err != nil {
-		t.Fatalf("Setenv() error = %v", err)
+	installer := &Installer{
+		projectGitRoot: tempDir,
+		globalGitRoot:  tempDir,
 	}
-	defer func() {
-		if err := os.Unsetenv("XDG_DATA_HOME"); err != nil {
-			t.Logf("Unsetenv() error = %v", err)
-		}
-	}()
-
-	// The manifest path when XDG_DATA_HOME is set
-	manifestPath := filepath.Join(tempDir, "kit", "git", "packages.json")
 
 	// Add an entry
 	entry := ManifestEntry{
@@ -315,58 +321,51 @@ func TestAddAndRemoveFromManifest(t *testing.T) {
 		Scope:  ScopeGlobal,
 	}
 
-	err := addEntryToManifest(entry, ScopeGlobal)
-	if err != nil {
-		t.Fatalf("addEntryToManifest() error = %v", err)
+	if err := installer.addToManifest(entry, ScopeGlobal); err != nil {
+		t.Fatalf("addToManifest() error = %v", err)
 	}
 
 	// Verify it was added
-	manifest, err := loadManifestFromPath(manifestPath)
+	manifest, err := installer.loadManifest(ScopeGlobal)
 	if err != nil {
-		t.Fatalf("loadManifestFromPath() error = %v", err)
+		t.Fatalf("loadManifest() error = %v", err)
 	}
 	if len(manifest.Packages) != 1 {
 		t.Errorf("Expected 1 package, got %d", len(manifest.Packages))
 	}
 
 	// Remove it
-	err = removeEntryFromManifest("github.com/user/repo", ScopeGlobal)
-	if err != nil {
-		t.Fatalf("removeEntryFromManifest() error = %v", err)
+	if err := installer.removeFromManifest("github.com/user/repo", ScopeGlobal); err != nil {
+		t.Fatalf("removeFromManifest() error = %v", err)
 	}
 
 	// Verify it was removed
-	manifest, err = loadManifestFromPath(manifestPath)
+	manifest, err = installer.loadManifest(ScopeGlobal)
 	if err != nil {
-		t.Fatalf("loadManifestFromPath() error = %v", err)
+		t.Fatalf("loadManifest() error = %v", err)
 	}
 	if len(manifest.Packages) != 0 {
 		t.Errorf("Expected 0 packages, got %d", len(manifest.Packages))
 	}
 }
 
+// TestFindInManifest writes a manifest file directly to the path
+// resolved by the package-level manifestPathForScope helper and then
+// confirms FindInManifest locates the entry by identity (and returns
+// nil for a non-existent identity).
 func TestFindInManifest(t *testing.T) {
 	tempDir := t.TempDir()
-	if err := os.Setenv("XDG_DATA_HOME", tempDir); err != nil {
-		t.Fatalf("Setenv() error = %v", err)
-	}
-	defer func() {
-		if err := os.Unsetenv("XDG_DATA_HOME"); err != nil {
-			t.Logf("Unsetenv() error = %v", err)
-		}
-	}()
+	t.Setenv("XDG_DATA_HOME", tempDir)
 
-	// Add an entry to global manifest
-	entry := ManifestEntry{
-		Source: "git:github.com/user/repo",
-		Host:   "github.com",
-		Path:   "user/repo",
-		Scope:  ScopeGlobal,
+	// Write a manifest entry directly via the package-level path resolver
+	// so FindInManifest (which uses manifestPathForScope) can read it back.
+	manifestPath := manifestPathForScope(ScopeGlobal)
+	if err := os.MkdirAll(filepath.Dir(manifestPath), 0755); err != nil {
+		t.Fatalf("MkdirAll() error = %v", err)
 	}
-
-	err := addEntryToManifest(entry, ScopeGlobal)
-	if err != nil {
-		t.Fatalf("addEntryToManifest() error = %v", err)
+	data := []byte(`{"packages":[{"source":"git:github.com/user/repo","repo":"","host":"github.com","path":"user/repo","pinned":false,"scope":"global","installed":"0001-01-01T00:00:00Z"}]}`)
+	if err := os.WriteFile(manifestPath, data, 0644); err != nil {
+		t.Fatalf("WriteFile() error = %v", err)
 	}
 
 	// Find it

internal/extensions/llmusage_test.go

@@ -0,0 +1,119 @@
+package extensions
+
+import "testing"
+
+func TestRunner_EmitLLMUsage(t *testing.T) {
+	var got LLMUsageEvent
+	var called bool
+	ext := makeHandlerExt("llmusage.go", map[EventType][]HandlerFunc{
+		LLMUsage: {
+			func(e Event, c Context) Result {
+				got = e.(LLMUsageEvent)
+				called = true
+				return nil
+			},
+		},
+	})
+
+	r := makeRunner(ext)
+	_, err := r.Emit(LLMUsageEvent{
+		InputTokens:  100,
+		OutputTokens: 50,
+		Cost:         0.0012,
+		Model:        "claude-sonnet-4-5-20250929",
+		Provider:     "anthropic",
+		StepNumber:   2,
+		FinishReason: "tool_calls",
+	})
+	if err != nil {
+		t.Fatalf("emit: %v", err)
+	}
+	if !called {
+		t.Fatal("expected LLMUsage handler to be called")
+	}
+	if got.InputTokens != 100 || got.OutputTokens != 50 {
+		t.Errorf("token fields not propagated: %+v", got)
+	}
+	if got.Cost != 0.0012 {
+		t.Errorf("cost not propagated, got %v", got.Cost)
+	}
+	if got.Model != "claude-sonnet-4-5-20250929" || got.Provider != "anthropic" {
+		t.Errorf("model/provider not propagated: %+v", got)
+	}
+	if got.StepNumber != 2 || got.FinishReason != "tool_calls" {
+		t.Errorf("step/finish reason not propagated: %+v", got)
+	}
+}
+
+func TestRunner_LLMUsageRegisteredViaTestAPI(t *testing.T) {
+	// Verify NewTestAPI wires up onLLMUsage so the extension can call
+	// api.OnLLMUsage during Init.
+	ext := &LoadedExtension{Handlers: make(map[EventType][]HandlerFunc)}
+	api := NewTestAPI(ext)
+
+	var calls int
+	api.OnLLMUsage(func(e LLMUsageEvent, c Context) {
+		calls++
+	})
+
+	if len(ext.Handlers[LLMUsage]) != 1 {
+		t.Fatalf("expected 1 LLMUsage handler registered, got %d", len(ext.Handlers[LLMUsage]))
+	}
+
+	r := makeRunner(*ext)
+	_, _ = r.Emit(LLMUsageEvent{InputTokens: 1})
+	if calls != 1 {
+		t.Errorf("expected handler called once, got %d", calls)
+	}
+}
+
+func TestAgentEndEvent_EnrichedFields(t *testing.T) {
+	// Verify the enriched event carries through Emit without mangling.
+	var got AgentEndEvent
+	ext := makeHandlerExt("end.go", map[EventType][]HandlerFunc{
+		AgentEnd: {
+			func(e Event, c Context) Result {
+				got = e.(AgentEndEvent)
+				return nil
+			},
+		},
+	})
+	r := makeRunner(ext)
+	_, err := r.Emit(AgentEndEvent{
+		Response:              "done",
+		StopReason:            "completed",
+		ToolCallCount:         3,
+		ToolNames:             []string{"bash", "read", "bash"},
+		LLMCallCount:          4,
+		InputTokensDelta:      1500,
+		OutputTokensDelta:     400,
+		CacheReadTokensDelta:  200,
+		CacheWriteTokensDelta: 100,
+		CostDelta:             0.0123,
+		DurationMs:            2500,
+	})
+	if err != nil {
+		t.Fatalf("emit: %v", err)
+	}
+	if got.ToolCallCount != 3 {
+		t.Errorf("ToolCallCount: got %d want 3", got.ToolCallCount)
+	}
+	if len(got.ToolNames) != 3 || got.ToolNames[0] != "bash" || got.ToolNames[2] != "bash" {
+		t.Errorf("ToolNames: %v", got.ToolNames)
+	}
+	if got.LLMCallCount != 4 {
+		t.Errorf("LLMCallCount: got %d want 4", got.LLMCallCount)
+	}
+	if got.InputTokensDelta != 1500 || got.OutputTokensDelta != 400 {
+		t.Errorf("token deltas: %+v", got)
+	}
+	if got.CacheReadTokensDelta != 200 || got.CacheWriteTokensDelta != 100 {
+		t.Errorf("cache deltas: %+v", got)
+	}
+	if got.CostDelta != 0.0123 {
+		t.Errorf("CostDelta: got %v", got.CostDelta)
+	}
+	if got.DurationMs != 2500 {
+		t.Errorf("DurationMs: got %d", got.DurationMs)
+	}
+}

internal/extensions/loader.go

@@ -34,59 +34,64 @@ func LoadExtensions(extraPaths []string) ([]LoadedExtension, error) {
 	for _, p := range paths {
 		ext, err := loadSingleExtension(p)
 		if err != nil {
-			log.Warn("skipping extension", "path", p, "err", err)
 			continue
 		}
 		loaded = append(loaded, *ext)
-		log.Debug("loaded extension", "path", p,
-			"handlers", countHandlers(ext),
-			"tools", len(ext.Tools),
-			"commands", len(ext.Commands),
-			"tool_renderers", len(ext.ToolRenderers))
+		log.Debug("loaded extension", "path", p, "handlers", countHandlers(ext), "tools", len(ext.Tools), "commands", len(ext.Commands), "tool_renderers", len(ext.ToolRenderers))
 	}
 	return loaded, nil
 }
 
+// pathSet is a thread-safe helper for deduplicating and ordering file paths.
+type pathSet struct {
+	m    map[string]bool
+	list []string
+}
+
+func newPathSet() *pathSet {
+	return &pathSet{m: make(map[string]bool)}
+}
+
+func (ps *pathSet) add(p string) bool {
+	abs, err := filepath.Abs(p)
+	if err != nil {
+		return false
+	}
+	if ps.m[abs] {
+		return false
+	}
+	ps.m[abs] = true
+	ps.list = append(ps.list, abs)
+	return true
+}
+
 // discoverExtensionPaths returns deduplicated paths to extension files in
 // load-order (global first, then project-local, then explicit).
 func discoverExtensionPaths(extraPaths []string) []string {
-	seen := make(map[string]bool)
-	var paths []string
-
-	add := func(p string) {
-		abs, err := filepath.Abs(p)
-		if err != nil {
-			return
-		}
-		if seen[abs] {
-			return
-		}
-		seen[abs] = true
-		paths = append(paths, abs)
-	}
+	ps := newPathSet()
 
 	// Global extensions: $XDG_CONFIG_HOME/kit/extensions/ (default ~/.config/kit/extensions/)
 	globalDir := globalExtensionsDir()
 	for _, p := range findExtensionsInDir(globalDir) {
-		add(p)
+		ps.add(p)
 	}
 
 	// Global installed git packages: $XDG_DATA_HOME/kit/git/
 	globalGitDir := globalGitInstallRoot()
 	for _, p := range findExtensionsInGitPackages(globalGitDir) {
-		add(p)
+		ps.add(p)
 	}
 
 	// Project-local extensions: .kit/extensions/
 	localDir := filepath.Join(".kit", "extensions")
 	for _, p := range findExtensionsInDir(localDir) {
-		add(p)
+		ps.add(p)
 	}
 
 	// Project-local installed git packages: .kit/git/
 	projectGitDir := filepath.Join(".kit", "git")
 	for _, p := range findExtensionsInGitPackages(projectGitDir) {
-		add(p)
+		ps.add(p)
 	}
 
 	// Explicit paths (highest precedence)
@@ -97,14 +102,14 @@ func discoverExtensionPaths(extraPaths []string) []string {
 		}
 		if info.IsDir() {
 			for _, found := range findExtensionsInDir(p) {
-				add(found)
+				ps.add(found)
 			}
 		} else if strings.HasSuffix(p, ".go") {
-			add(p)
+			ps.add(p)
 		}
 	}
 
-	return paths
+	return ps.list
 }
 
 // findExtensionsInDir returns .go files in dir and main.go in immediate subdirs.
@@ -123,7 +128,7 @@ func findExtensionsInDir(dir string) []string {
 
 	for _, entry := range entries {
 		full := filepath.Join(dir, entry.Name())
-		if !entry.IsDir() && strings.HasSuffix(entry.Name(), ".go") {
+		if !entry.IsDir() && strings.HasSuffix(entry.Name(), ".go") && !strings.HasSuffix(entry.Name(), "_test.go") {
 			results = append(results, full)
 		} else if entry.IsDir() {
 			main := filepath.Join(full, "main.go")
@@ -180,9 +185,13 @@ func findExtensionsInRepo(repoPath string) []string {
 			isExtDir := base == "extensions" || base == "ext" ||
 				strings.HasSuffix(base, "-extensions") || strings.HasSuffix(base, "-ext")
 
-			isExamplesSubdir := relPath == "examples" || strings.HasPrefix(relPath, "examples/")
+			// Allow walking into examples/ so we can reach examples/extensions/ etc,
+			// but don't treat examples/ itself or non-extension subdirs as extension locations.
+			if relPath == "examples" {
+				return nil
+			}
 
-			if !isExtDir && !isExamplesSubdir {
+			if !isExtDir {
 				mainPath := filepath.Join(path, "main.go")
 				if _, err := os.Stat(mainPath); err == nil {
 					if relPath == base { // Top-level directory
@@ -192,13 +201,6 @@ func findExtensionsInRepo(repoPath string) []string {
 						}
 						return filepath.SkipDir
 					}
-					if isExamplesSubdir || isExtDir {
-						if !multiFileDirs[relPath] {
-							multiFileDirs[relPath] = true
-							results = append(results, mainPath)
-						}
-						return filepath.SkipDir
-					}
 				}
 				return filepath.SkipDir
 			}
@@ -217,7 +219,7 @@ func findExtensionsInRepo(repoPath string) []string {
 		}
 
 		// It's a file
-		if !strings.HasSuffix(info.Name(), ".go") {
+		if !strings.HasSuffix(info.Name(), ".go") || strings.HasSuffix(info.Name(), "_test.go") {
 			return nil
 		}
 
@@ -427,6 +429,24 @@ func loadSingleExtension(path string) (*LoadedExtension, error) {
 				return *r
 			})
 		},
+		onToolCallInputStart: func(h func(ToolCallInputStartEvent, Context)) {
+			reg(ToolCallInputStart, func(e Event, c Context) Result {
+				h(e.(ToolCallInputStartEvent), c)
+				return nil
+			})
+		},
+		onToolCallInputDelta: func(h func(ToolCallInputDeltaEvent, Context)) {
+			reg(ToolCallInputDelta, func(e Event, c Context) Result {
+				h(e.(ToolCallInputDeltaEvent), c)
+				return nil
+			})
+		},
+		onToolCallInputEnd: func(h func(ToolCallInputEndEvent, Context)) {
+			reg(ToolCallInputEnd, func(e Event, c Context) Result {
+				h(e.(ToolCallInputEndEvent), c)
+				return nil
+			})
+		},
 		onToolExecStart: func(h func(ToolExecutionStartEvent, Context)) {
 			reg(ToolExecutionStart, func(e Event, c Context) Result {
 				h(e.(ToolExecutionStartEvent), c)
@@ -580,6 +600,81 @@ func loadSingleExtension(path string) (*LoadedExtension, error) {
 		registerShortcutFn: func(def ShortcutDef, handler func(Context)) {
 			ext.Shortcuts = append(ext.Shortcuts, ShortcutEntry{Def: def, Handler: handler})
 		},
+		onSubagentStart: func(h func(SubagentStartEvent, Context)) {
+			reg(SubagentStart, func(e Event, c Context) Result {
+				h(e.(SubagentStartEvent), c)
+				return nil
+			})
+		},
+		onSubagentChunk: func(h func(SubagentChunkEvent, Context)) {
+			reg(SubagentChunk, func(e Event, c Context) Result {
+				h(e.(SubagentChunkEvent), c)
+				return nil
+			})
+		},
+		onSubagentEnd: func(h func(SubagentEndEvent, Context)) {
+			reg(SubagentEnd, func(e Event, c Context) Result {
+				h(e.(SubagentEndEvent), c)
+				return nil
+			})
+		},
+		onStepStart: func(h func(StepStartEvent, Context)) {
+			reg(StepStart, func(e Event, c Context) Result {
+				h(e.(StepStartEvent), c)
+				return nil
+			})
+		},
+		onStepFinish: func(h func(StepFinishEvent, Context)) {
+			reg(StepFinish, func(e Event, c Context) Result {
+				h(e.(StepFinishEvent), c)
+				return nil
+			})
+		},
+		onReasoningStart: func(h func(ReasoningStartEvent, Context)) {
+			reg(ReasoningStart, func(e Event, c Context) Result {
+				h(e.(ReasoningStartEvent), c)
+				return nil
+			})
+		},
+		onWarnings: func(h func(WarningsEvent, Context)) {
+			reg(Warnings, func(e Event, c Context) Result {
+				h(e.(WarningsEvent), c)
+				return nil
+			})
+		},
+		onSource: func(h func(SourceEvent, Context)) {
+			reg(Source, func(e Event, c Context) Result {
+				h(e.(SourceEvent), c)
+				return nil
+			})
+		},
+		onError: func(h func(ErrorEvent, Context)) {
+			reg(Error, func(e Event, c Context) Result {
+				h(e.(ErrorEvent), c)
+				return nil
+			})
+		},
+		onRetry: func(h func(RetryEvent, Context)) {
+			reg(Retry, func(e Event, c Context) Result {
+				h(e.(RetryEvent), c)
+				return nil
+			})
+		},
+		onPrepareStep: func(h func(PrepareStepEvent, Context) *PrepareStepResult) {
+			reg(PrepareStep, func(e Event, c Context) Result {
+				r := h(e.(PrepareStepEvent), c)
+				if r == nil {
+					return nil
+				}
+				return *r
+			})
+		},
+		onLLMUsage: func(h func(LLMUsageEvent, Context)) {
+			reg(LLMUsage, func(e Event, c Context) Result {
+				h(e.(LLMUsageEvent), c)
+				return nil
+			})
+		},
 	}
 
 	// Call Init — the extension registers its handlers, tools, commands.

internal/extensions/manifest.go

@@ -72,30 +72,6 @@ func loadManifestFromPath(path string) (*Manifest, error) {
 	return &manifest, nil
 }
 
-// saveManifestToScope saves the manifest to the given scope.
-func saveManifestToScope(manifest *Manifest, scope InstallScope) error {
-	path := manifestPathForScope(scope)
-	return saveManifestToPath(manifest, path)
-}
-
-// saveManifestToPath saves a manifest to a specific file path.
-func saveManifestToPath(manifest *Manifest, path string) error {
-	if err := os.MkdirAll(filepath.Dir(path), 0755); err != nil {
-		return fmt.Errorf("creating manifest directory: %w", err)
-	}
-
-	data, err := json.MarshalIndent(manifest, "", "  ")
-	if err != nil {
-		return fmt.Errorf("encoding manifest: %w", err)
-	}
-
-	if err := os.WriteFile(path, data, 0644); err != nil {
-		return fmt.Errorf("writing manifest: %w", err)
-	}
-
-	return nil
-}
-
 // manifestPathForScope returns the manifest file path for a scope.
 func manifestPathForScope(scope InstallScope) string {
 	if scope == ScopeProject {
@@ -113,55 +89,6 @@ func manifestPathForScope(scope InstallScope) string {
 	return filepath.Join(base, "kit", "git", "packages.json")
 }
 
-// GetGlobalManifest returns the global manifest.
-func GetGlobalManifest() (*Manifest, error) {
-	return loadManifestFromScope(ScopeGlobal)
-}
-
-// GetProjectManifest returns the project manifest.
-func GetProjectManifest() (*Manifest, error) {
-	return loadManifestFromScope(ScopeProject)
-}
-
-// addEntryToManifest adds or replaces an entry in the manifest for a scope.
-func addEntryToManifest(entry ManifestEntry, scope InstallScope) error {
-	manifest, err := loadManifestFromScope(scope)
-	if err != nil {
-		return err
-	}
-
-	// Remove any existing entry with same identity
-	identity := entry.Identity()
-	filtered := make([]ManifestEntry, 0, len(manifest.Packages))
-	for _, p := range manifest.Packages {
-		if p.Identity() != identity {
-			filtered = append(filtered, p)
-		}
-	}
-	filtered = append(filtered, entry)
-	manifest.Packages = filtered
-
-	return saveManifestToScope(manifest, scope)
-}
-
-// removeEntryFromManifest removes an entry by identity from the manifest for a scope.
-func removeEntryFromManifest(identity string, scope InstallScope) error {
-	manifest, err := loadManifestFromScope(scope)
-	if err != nil {
-		return err
-	}
-
-	filtered := make([]ManifestEntry, 0, len(manifest.Packages))
-	for _, p := range manifest.Packages {
-		if p.Identity() != identity {
-			filtered = append(filtered, p)
-		}
-	}
-	manifest.Packages = filtered
-
-	return saveManifestToScope(manifest, scope)
-}
-
 // FindInManifest finds an entry by identity in either global or project manifest.
 // Returns the entry and its scope, or nil if not found.
 func FindInManifest(identity string) (*ManifestEntry, InstallScope, error) {
@@ -253,10 +180,13 @@ func ScanForExtensions(dir string) ([]ExtensionPreview, error) {
 			isExtDir := base == "extensions" || base == "ext" ||
 				strings.HasSuffix(base, "-extensions") || strings.HasSuffix(base, "-ext")
 
-			// Or check if it's a subdirectory of examples/ that might contain extensions
-			isExamplesSubdir := relPath == "examples" || strings.HasPrefix(relPath, "examples/")
+			// Allow walking into examples/ so we can reach examples/extensions/ etc,
+			// but don't treat examples/ itself or non-extension subdirs as extension locations.
+			if relPath == "examples" {
+				return nil
+			}
 
-			if !isExtDir && !isExamplesSubdir {
+			if !isExtDir {
 				// Check for main.go before skipping
 				mainPath := filepath.Join(path, "main.go")
 				if _, err := os.Stat(mainPath); err == nil {
@@ -272,18 +202,6 @@ func ScanForExtensions(dir string) ([]ExtensionPreview, error) {
 						}
 						return filepath.SkipDir
 					}
-					// Inside a valid extensions directory
-					if isExamplesSubdir || isExtDir {
-						if !multiFileDirs[relPath] {
-							multiFileDirs[relPath] = true
-							previews = append(previews, ExtensionPreview{
-								Path:   "./" + relPath + "/main.go",
-								Name:   deriveExtensionName(relPath+"/main.go", true),
-								IsMain: true,
-							})
-						}
-						return filepath.SkipDir
-					}
 				}
 
 				// Not an extension location
@@ -309,7 +227,7 @@ func ScanForExtensions(dir string) ([]ExtensionPreview, error) {
 		}
 
 		// It's a file - check if it's a valid extension
-		if !strings.HasSuffix(info.Name(), ".go") {
+		if !strings.HasSuffix(info.Name(), ".go") || strings.HasSuffix(info.Name(), "_test.go") {
 			return nil
 		}
 

internal/extensions/runner.go

@@ -1,21 +1,96 @@
 package extensions
 
 import (
+	"bytes"
+	"encoding/json"
 	"fmt"
+	"log"
+	"maps"
 	"os"
+	"path/filepath"
+	"runtime"
 	"sort"
+	"strconv"
 	"strings"
 	"sync"
 
-	"github.com/charmbracelet/log"
 	"github.com/spf13/viper"
 )
 
+// ---------------------------------------------------------------------------
+// reentrantMu — a per-extension mutex that allows the same goroutine to
+// re-enter (e.g. handler → ctx.EmitCustomEvent → handler in same extension).
+// Different goroutines are serialized, preventing concurrent state mutation.
+// ---------------------------------------------------------------------------
+
+type reentrantMu struct {
+	mu    sync.Mutex
+	cond  *sync.Cond
+	owner int64 // goroutine ID that holds the lock, or 0
+	depth int   // re-entrancy depth
+}
+
+// initReentrantMu initializes the reentrant mutex in-place. Must be called
+// after the struct is at its final memory location (not before copying).
+func (r *reentrantMu) init() {
+	r.cond = sync.NewCond(&r.mu)
+}
+
+// lock acquires the mutex. If the calling goroutine already holds it, the
+// call succeeds immediately (re-entrant). Every call to lock must be paired
+// with a call to unlock.
+func (r *reentrantMu) lock() {
+	gid := goroutineID()
+	r.mu.Lock()
+	if r.owner == gid {
+		// Re-entrant: same goroutine already holds the lock.
+		r.depth++
+		r.mu.Unlock()
+		return
+	}
+	// Wait for the current owner to release.
+	for r.owner != 0 {
+		r.cond.Wait() // releases mu, blocks, re-acquires mu on wake
+	}
+	r.owner = gid
+	r.depth = 1
+	r.mu.Unlock()
+}
+
+// unlock releases the mutex (or decrements re-entrancy depth).
+func (r *reentrantMu) unlock() {
+	r.mu.Lock()
+	r.depth--
+	if r.depth == 0 {
+		r.owner = 0
+		r.cond.Signal()
+	}
+	r.mu.Unlock()
+}
+
+// goroutineID extracts the current goroutine's ID from runtime.Stack output.
+// This is a well-known technique used by Go testing infrastructure.
+func goroutineID() int64 {
+	var buf [64]byte
+	n := runtime.Stack(buf[:], false)
+	// Stack output starts with "goroutine NNN ["
+	s := buf[:n]
+	s = s[len("goroutine "):]
+	s = s[:bytes.IndexByte(s, ' ')]
+	id, _ := strconv.ParseInt(string(s), 10, 64)
+	return id
+}
+
 // Runner manages loaded extensions and dispatches events to their handlers
 // sequentially. Handlers execute in extension
 // load order; for cancellable events the first blocking result wins.
+//
+// Each extension has a dedicated reentrant mutex so that handlers for the
+// same extension are serialized (preventing data races on shared package-level
+// state), while handlers for different extensions may execute concurrently.
 type Runner struct {
 	extensions      []LoadedExtension
+	extMu           []reentrantMu // per-extension reentrant mutex, indexed by extension position
 	ctx             Context
 	widgets         map[string]WidgetConfig   // keyed by widget ID
 	statusEntries   map[string]StatusBarEntry // keyed by status key
@@ -26,9 +101,24 @@ type Runner struct {
 	disabledTools   map[string]bool           // nil = all tools enabled
 	customEventSubs map[string][]func(string) // inter-extension event bus
 	optionOverrides map[string]string         // runtime option overrides
+	configStore     *viper.Viper              // per-instance config store (nil = global)
+	state           map[string]string         // session-scoped extension state (last-write-wins)
+	stateMu         sync.RWMutex              // guards state independently of mu
+	saverMu         sync.Mutex                // serializes stateSaver invocations so atomic-rename writes don't interleave
+	stateSaver      func()                    // optional persistence hook invoked after each state mutation
 	mu              sync.RWMutex
 }
 
+// SetConfigStore sets the per-instance configuration store used by GetOption
+// to resolve "options.<name>" config values. When unset (nil), GetOption falls
+// back to the process-global viper store. Threading a per-Kit store keeps
+// extension option resolution isolated between Kit instances.
+func (r *Runner) SetConfigStore(v *viper.Viper) {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	r.configStore = v
+}
+
 // ShortcutEntry pairs a shortcut definition with its handler.
 type ShortcutEntry struct {
 	Def     ShortcutDef
@@ -52,15 +142,296 @@ type LoadedExtension struct {
 
 // NewRunner creates a Runner from a set of loaded extensions.
 func NewRunner(exts []LoadedExtension) *Runner {
-	return &Runner{extensions: exts}
+	mus := make([]reentrantMu, len(exts))
+	for i := range mus {
+		mus[i].init()
+	}
+	return &Runner{extensions: exts, extMu: mus}
 }
 
 // SetContext updates the runtime context (session ID, model, etc.) that is
-// passed to every handler invocation. Thread-safe.
+// passed to every handler invocation. Nil function fields are replaced with
+// safe no-ops so extension handlers never panic on a missing callback.
+// Thread-safe.
 func (r *Runner) SetContext(ctx Context) {
 	r.mu.Lock()
 	defer r.mu.Unlock()
-	r.ctx = ctx
+	r.ctx = normalizeContext(ctx)
+}
+
+// normalizeContext replaces nil function fields in ctx with no-op stubs so
+// that extension handlers can call any ctx method without a nil-function panic.
+func normalizeContext(ctx Context) Context {
+	if ctx.Print == nil {
+		ctx.Print = func(string) {}
+	}
+	if ctx.PrintInfo == nil {
+		ctx.PrintInfo = func(string) {}
+	}
+	if ctx.PrintError == nil {
+		ctx.PrintError = func(string) {}
+	}
+	if ctx.PrintBlock == nil {
+		ctx.PrintBlock = func(PrintBlockOpts) {}
+	}
+	if ctx.SendMessage == nil {
+		ctx.SendMessage = func(string) {}
+	}
+	if ctx.CancelAndSend == nil {
+		ctx.CancelAndSend = func(string) {}
+	}
+	if ctx.Abort == nil {
+		ctx.Abort = func() {}
+	}
+	if ctx.IsIdle == nil {
+		ctx.IsIdle = func() bool { return true }
+	}
+	if ctx.Compact == nil {
+		ctx.Compact = func(CompactConfig) error { return fmt.Errorf("compact not available") }
+	}
+	if ctx.SendMultimodalMessage == nil {
+		ctx.SendMultimodalMessage = func(string, []FilePart) {}
+	}
+	if ctx.GetSessionUsage == nil {
+		ctx.GetSessionUsage = func() SessionUsage { return SessionUsage{} }
+	}
+	if ctx.SetWidget == nil {
+		ctx.SetWidget = func(WidgetConfig) {}
+	}
+	if ctx.RemoveWidget == nil {
+		ctx.RemoveWidget = func(string) {}
+	}
+	if ctx.SetHeader == nil {
+		ctx.SetHeader = func(HeaderFooterConfig) {}
+	}
+	if ctx.RemoveHeader == nil {
+		ctx.RemoveHeader = func() {}
+	}
+	if ctx.SetFooter == nil {
+		ctx.SetFooter = func(HeaderFooterConfig) {}
+	}
+	if ctx.RemoveFooter == nil {
+		ctx.RemoveFooter = func() {}
+	}
+	if ctx.PromptSelect == nil {
+		ctx.PromptSelect = func(PromptSelectConfig) PromptSelectResult {
+			return PromptSelectResult{Cancelled: true}
+		}
+	}
+	if ctx.PromptConfirm == nil {
+		ctx.PromptConfirm = func(PromptConfirmConfig) PromptConfirmResult {
+			return PromptConfirmResult{Cancelled: true}
+		}
+	}
+	if ctx.PromptInput == nil {
+		ctx.PromptInput = func(PromptInputConfig) PromptInputResult {
+			return PromptInputResult{Cancelled: true}
+		}
+	}
+	if ctx.PromptMultiSelect == nil {
+		ctx.PromptMultiSelect = func(PromptMultiSelectConfig) PromptMultiSelectResult {
+			return PromptMultiSelectResult{Cancelled: true}
+		}
+	}
+	if ctx.ShowOverlay == nil {
+		ctx.ShowOverlay = func(OverlayConfig) OverlayResult {
+			return OverlayResult{Cancelled: true, Index: -1}
+		}
+	}
+	if ctx.SetEditor == nil {
+		ctx.SetEditor = func(EditorConfig) {}
+	}
+	if ctx.ResetEditor == nil {
+		ctx.ResetEditor = func() {}
+	}
+	if ctx.SetEditorText == nil {
+		ctx.SetEditorText = func(string) {}
+	}
+	if ctx.SetUIVisibility == nil {
+		ctx.SetUIVisibility = func(UIVisibility) {}
+	}
+	if ctx.SetStatus == nil {
+		ctx.SetStatus = func(string, string, int) {}
+	}
+	if ctx.RemoveStatus == nil {
+		ctx.RemoveStatus = func(string) {}
+	}
+	if ctx.GetContextStats == nil {
+		ctx.GetContextStats = func() ContextStats { return ContextStats{} }
+	}
+	if ctx.GetMessages == nil {
+		ctx.GetMessages = func() []SessionMessage { return nil }
+	}
+	if ctx.GetSessionPath == nil {
+		ctx.GetSessionPath = func() string { return "" }
+	}
+	if ctx.AppendEntry == nil {
+		ctx.AppendEntry = func(string, string) (string, error) { return "", nil }
+	}
+	if ctx.GetEntries == nil {
+		ctx.GetEntries = func(string) []ExtensionEntry { return nil }
+	}
+	if ctx.SetState == nil {
+		ctx.SetState = func(string, string) {}
+	}
+	if ctx.GetState == nil {
+		ctx.GetState = func(string) (string, bool) { return "", false }
+	}
+	if ctx.DeleteState == nil {
+		ctx.DeleteState = func(string) {}
+	}
+	if ctx.ListState == nil {
+		ctx.ListState = func() []string { return nil }
+	}
+	if ctx.GetOption == nil {
+		ctx.GetOption = func(string) string { return "" }
+	}
+	if ctx.SetOption == nil {
+		ctx.SetOption = func(string, string) {}
+	}
+	if ctx.SetModel == nil {
+		ctx.SetModel = func(string) error { return nil }
+	}
+	if ctx.GetAvailableModels == nil {
+		ctx.GetAvailableModels = func() []ModelInfoEntry { return nil }
+	}
+	if ctx.EmitCustomEvent == nil {
+		ctx.EmitCustomEvent = func(string, string) {}
+	}
+	if ctx.GetAllTools == nil {
+		ctx.GetAllTools = func() []ToolInfo { return nil }
+	}
+	if ctx.SetActiveTools == nil {
+		ctx.SetActiveTools = func([]string) {}
+	}
+	if ctx.Exit == nil {
+		ctx.Exit = func() {}
+	}
+	if ctx.Complete == nil {
+		ctx.Complete = func(CompleteRequest) (CompleteResponse, error) {
+			return CompleteResponse{}, nil
+		}
+	}
+	if ctx.SuspendTUI == nil {
+		ctx.SuspendTUI = func(callback func()) error { callback(); return nil }
+	}
+	if ctx.RenderMessage == nil {
+		ctx.RenderMessage = func(string, string) {}
+	}
+	if ctx.RegisterTheme == nil {
+		ctx.RegisterTheme = func(string, ThemeColorConfig) {}
+	}
+	if ctx.SetTheme == nil {
+		ctx.SetTheme = func(string) error { return nil }
+	}
+	if ctx.ListThemes == nil {
+		ctx.ListThemes = func() []string { return nil }
+	}
+	if ctx.ReloadExtensions == nil {
+		ctx.ReloadExtensions = func() error { return nil }
+	}
+	if ctx.SpawnSubagent == nil {
+		ctx.SpawnSubagent = func(SubagentConfig) (*SubagentHandle, *SubagentResult, error) {
+			return nil, nil, nil
+		}
+	}
+
+	// -------------------------------------------------------------------------
+	// Tree Navigation API no-ops
+	// -------------------------------------------------------------------------
+	if ctx.GetTreeNode == nil {
+		ctx.GetTreeNode = func(string) *TreeNode { return nil }
+	}
+	if ctx.GetCurrentBranch == nil {
+		ctx.GetCurrentBranch = func() []TreeNode { return nil }
+	}
+	if ctx.GetChildren == nil {
+		ctx.GetChildren = func(string) []string { return nil }
+	}
+	if ctx.NavigateTo == nil {
+		ctx.NavigateTo = func(string) TreeNavigationResult {
+			return TreeNavigationResult{Success: false, Error: "not implemented"}
+		}
+	}
+	if ctx.SummarizeBranch == nil {
+		ctx.SummarizeBranch = func(string, string) string {
+			return ""
+		}
+	}
+	if ctx.CollapseBranch == nil {
+		ctx.CollapseBranch = func(string, string, string) TreeNavigationResult {
+			return TreeNavigationResult{Success: false, Error: "not implemented"}
+		}
+	}
+
+	// -------------------------------------------------------------------------
+	// Skill Loading API no-ops
+	// -------------------------------------------------------------------------
+	if ctx.LoadSkill == nil {
+		ctx.LoadSkill = func(string) (*Skill, string) { return nil, "" }
+	}
+	if ctx.LoadSkillsFromDir == nil {
+		ctx.LoadSkillsFromDir = func(string) SkillLoadResult { return SkillLoadResult{} }
+	}
+	if ctx.DiscoverSkills == nil {
+		ctx.DiscoverSkills = func() SkillLoadResult { return SkillLoadResult{} }
+	}
+	if ctx.InjectSkillAsContext == nil {
+		ctx.InjectSkillAsContext = func(string) string { return "" }
+	}
+	if ctx.InjectRawSkillAsContext == nil {
+		ctx.InjectRawSkillAsContext = func(string) string { return "" }
+	}
+	if ctx.GetAvailableSkills == nil {
+		ctx.GetAvailableSkills = func() []Skill { return nil }
+	}
+
+	// -------------------------------------------------------------------------
+	// Template Parsing API no-ops
+	// -------------------------------------------------------------------------
+	if ctx.ParseTemplate == nil {
+		ctx.ParseTemplate = func(string, string) PromptTemplate { return PromptTemplate{} }
+	}
+	if ctx.RenderTemplate == nil {
+		ctx.RenderTemplate = func(PromptTemplate, map[string]string) string { return "" }
+	}
+	if ctx.ParseArguments == nil {
+		ctx.ParseArguments = func(string, ArgumentPattern) ParseResult { return ParseResult{} }
+	}
+	if ctx.SimpleParseArguments == nil {
+		ctx.SimpleParseArguments = func(string, int) []string { return nil }
+	}
+	if ctx.EvaluateModelConditional == nil {
+		ctx.EvaluateModelConditional = func(string) bool { return false }
+	}
+	if ctx.RenderWithModelConditionals == nil {
+		ctx.RenderWithModelConditionals = func(string) string { return "" }
+	}
+
+	// -------------------------------------------------------------------------
+	// Model Resolution API no-ops
+	// -------------------------------------------------------------------------
+	if ctx.ResolveModelChain == nil {
+		ctx.ResolveModelChain = func([]string) ModelResolutionResult {
+			return ModelResolutionResult{Error: "not implemented"}
+		}
+	}
+	if ctx.GetModelCapabilities == nil {
+		ctx.GetModelCapabilities = func(string) (ModelCapabilities, string) {
+			return ModelCapabilities{}, "not implemented"
+		}
+	}
+	if ctx.CheckModelAvailable == nil {
+		ctx.CheckModelAvailable = func(string) bool { return false }
+	}
+	if ctx.GetCurrentProvider == nil {
+		ctx.GetCurrentProvider = func() string { return "" }
+	}
+	if ctx.GetCurrentModelID == nil {
+		ctx.GetCurrentModelID = func() string { return "" }
+	}
+
+	return ctx
 }
 
 // GetContext returns a snapshot of the current runtime context. Thread-safe.
@@ -102,13 +473,15 @@ func (r *Runner) Emit(event Event) (Result, error) {
 	for i := range r.extensions {
 		ext := &r.extensions[i]
 		handlers := ext.Handlers[event.Type()]
+		if len(handlers) == 0 {
+			continue
+		}
+
+		r.extMu[i].lock()
 		for _, handler := range handlers {
 			result, err := safeCall(handler, event, ctx)
 			if err != nil {
-				log.Warn("extension handler error",
-					"path", ext.Path,
-					"event", event.Type(),
-					"err", err)
+				log.Printf("WARN extension handler error: path=%s event=%s err=%v", ext.Path, event.Type(), err)
 				continue
 			}
 			if result == nil {
@@ -117,6 +490,7 @@ func (r *Runner) Emit(event Event) (Result, error) {
 
 			// Check for blocking/short-circuit results.
 			if isBlocking(result) {
+				r.extMu[i].unlock()
 				return result, nil
 			}
 
@@ -124,6 +498,7 @@ func (r *Runner) Emit(event Event) (Result, error) {
 			// the caller is responsible for applying the modifications.
 			accumulated = result
 		}
+		r.extMu[i].unlock()
 	}
 	return accumulated, nil
 }
@@ -389,6 +764,168 @@ func (r *Runner) GetMessageRenderer(name string) *MessageRendererConfig {
 	return nil
 }
 
+// ---------------------------------------------------------------------------
+// Extension state store (session-scoped, last-write-wins)
+// ---------------------------------------------------------------------------
+
+// SetState records a key-value pair in the runner's session-scoped extension
+// state store. The store is in-memory; callers wire SetStateSaver to persist
+// changes to a sidecar file. Thread-safe.
+//
+// When a saver is installed, concurrent SetState/DeleteState invocations are
+// serialized through saverMu so that overlapping snapshot-and-rename writes
+// cannot interleave (which would otherwise race on the shared tmp file and
+// risk persisting an older snapshot after a newer one).
+func (r *Runner) SetState(key, value string) {
+	r.stateMu.Lock()
+	if r.state == nil {
+		r.state = make(map[string]string)
+	}
+	r.state[key] = value
+	saver := r.stateSaver
+	r.stateMu.Unlock()
+	r.runSaver(saver)
+}
+
+// GetState returns the value previously stored via SetState, plus a bool
+// indicating whether the key was present. Thread-safe.
+func (r *Runner) GetState(key string) (string, bool) {
+	r.stateMu.RLock()
+	defer r.stateMu.RUnlock()
+	v, ok := r.state[key]
+	return v, ok
+}
+
+// DeleteState removes a key from the state store. No-op if the key is
+// missing. Thread-safe. Saver invocations are serialized via saverMu — see
+// SetState for the rationale.
+func (r *Runner) DeleteState(key string) {
+	r.stateMu.Lock()
+	_, existed := r.state[key]
+	if existed {
+		delete(r.state, key)
+	}
+	saver := r.stateSaver
+	r.stateMu.Unlock()
+	if !existed {
+		return
+	}
+	r.runSaver(saver)
+}
+
+// runSaver invokes the optional persistence callback under saverMu so
+// concurrent SetState/DeleteState writers cannot race on the shared tmp
+// file used by SaveStateToFile's atomic rename. The deferred Unlock
+// guarantees saverMu is released even if the saver panics.
+func (r *Runner) runSaver(saver func()) {
+	if saver == nil {
+		return
+	}
+	r.saverMu.Lock()
+	defer r.saverMu.Unlock()
+	saver()
+}
+
+// ListState returns all keys currently in the state store, in unspecified
+// order. Thread-safe.
+func (r *Runner) ListState() []string {
+	r.stateMu.RLock()
+	defer r.stateMu.RUnlock()
+	if len(r.state) == 0 {
+		return nil
+	}
+	keys := make([]string, 0, len(r.state))
+	for k := range r.state {
+		keys = append(keys, k)
+	}
+	return keys
+}
+
+// SetStateSaver installs an optional persistence hook invoked after each
+// mutation to the state store (SetState / DeleteState / LoadStateFromFile).
+// Pass nil to disable persistence. Thread-safe.
+func (r *Runner) SetStateSaver(saver func()) {
+	r.stateMu.Lock()
+	defer r.stateMu.Unlock()
+	r.stateSaver = saver
+}
+
+// SnapshotState returns a copy of the current state store as a
+// fresh map. Useful for persisting to disk without holding the lock.
+// Thread-safe.
+func (r *Runner) SnapshotState() map[string]string {
+	r.stateMu.RLock()
+	defer r.stateMu.RUnlock()
+	if len(r.state) == 0 {
+		return nil
+	}
+	copyMap := make(map[string]string, len(r.state))
+	maps.Copy(copyMap, r.state)
+	return copyMap
+}
+
+// LoadStateFromFile reads a JSON map from path and replaces the in-memory
+// state store with its contents. Missing or empty files are treated as
+// "no prior state": the in-memory store is replaced with an empty map so
+// callers can safely switch sessions without leaking keys from a prior
+// session into a new one. Malformed JSON returns the parse error without
+// touching the existing store. Thread-safe.
+func (r *Runner) LoadStateFromFile(path string) error {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			r.stateMu.Lock()
+			r.state = map[string]string{}
+			r.stateMu.Unlock()
+			return nil
+		}
+		return fmt.Errorf("reading extension state: %w", err)
+	}
+	if len(data) == 0 {
+		r.stateMu.Lock()
+		r.state = map[string]string{}
+		r.stateMu.Unlock()
+		return nil
+	}
+	var loaded map[string]string
+	if err := json.Unmarshal(data, &loaded); err != nil {
+		return fmt.Errorf("parsing extension state: %w", err)
+	}
+	r.stateMu.Lock()
+	r.state = loaded
+	r.stateMu.Unlock()
+	return nil
+}
+
+// SaveStateToFile writes the current state store to path as JSON, creating
+// parent directories as needed. An empty store writes an empty object so
+// that consumers can distinguish "loaded but empty" from "never saved".
+// Writes are atomic via a tmp-file-and-rename sequence. Thread-safe.
+func (r *Runner) SaveStateToFile(path string) error {
+	snap := r.SnapshotState()
+	if snap == nil {
+		snap = map[string]string{}
+	}
+	data, err := json.MarshalIndent(snap, "", "  ")
+	if err != nil {
+		return fmt.Errorf("marshalling extension state: %w", err)
+	}
+	if dir := filepath.Dir(path); dir != "." && dir != "" {
+		if err := os.MkdirAll(dir, 0o755); err != nil {
+			return fmt.Errorf("creating state directory: %w", err)
+		}
+	}
+	tmp := path + ".tmp"
+	if err := os.WriteFile(tmp, data, 0o644); err != nil {
+		return fmt.Errorf("writing extension state: %w", err)
+	}
+	if err := os.Rename(tmp, path); err != nil {
+		_ = os.Remove(tmp)
+		return fmt.Errorf("renaming extension state: %w", err)
+	}
+	return nil
+}
+
 // ---------------------------------------------------------------------------
 // Hot-reload
 // ---------------------------------------------------------------------------
@@ -412,7 +949,9 @@ func (r *Runner) Reload(exts []LoadedExtension) {
 	r.uiVisibility = nil
 	r.disabledTools = nil
 	r.customEventSubs = nil
-	// optionOverrides are intentionally preserved.
+	// optionOverrides and state are intentionally preserved across reloads:
+	// they represent user/session intent (not extension code) and would be
+	// surprising to lose on a hot-reload.
 }
 
 // ---------------------------------------------------------------------------
@@ -442,9 +981,7 @@ func (r *Runner) EmitCustomEvent(name, data string) {
 	safeInvoke := func(h func(string)) {
 		defer func() {
 			if rec := recover(); rec != nil {
-				log.Warn("custom event handler panicked",
-					"event", name,
-					"err", fmt.Sprintf("%v", rec))
+				log.Printf("WARN custom event handler panicked: event=%s err=%v", name, rec)
 			}
 		}()
 		h(data)
@@ -452,11 +989,17 @@ func (r *Runner) EmitCustomEvent(name, data string) {
 
 	// Extension-registered handlers first (in load order).
 	for i := range r.extensions {
-		for _, h := range r.extensions[i].CustomEventHandlers[name] {
+		extHandlers := r.extensions[i].CustomEventHandlers[name]
+		if len(extHandlers) == 0 {
+			continue
+		}
+		r.extMu[i].lock()
+		for _, h := range extHandlers {
 			safeInvoke(h)
 		}
+		r.extMu[i].unlock()
 	}
-	// Then dynamic subscriptions.
+	// Then dynamic subscriptions (not extension-scoped, no per-ext lock).
 	for _, h := range dynamicHandlers {
 		safeInvoke(h)
 	}
@@ -523,7 +1066,13 @@ func (r *Runner) GetOption(name string) string {
 
 	// 3. Viper config: options.<name>
 	configKey := "options." + name
-	if v := viper.GetString(configKey); v != "" {
+	r.mu.RLock()
+	store := r.configStore
+	r.mu.RUnlock()
+	if store == nil {
+		store = viper.GetViper()
+	}
+	if v := store.GetString(configKey); v != "" {
 		return v
 	}
 

internal/extensions/runner_test.go

@@ -1,6 +1,7 @@
 package extensions
 
 import (
+	"sync"
 	"testing"
 )
 
@@ -571,3 +572,142 @@ func TestRunner_ContextPrintNilSafe(t *testing.T) {
 		t.Fatalf("unexpected error: %v", err)
 	}
 }
+
+func TestRunner_ConcurrentEmitSameExtension(t *testing.T) {
+	// Verify that concurrent Emit calls for the same extension are serialized
+	// and don't cause data races on shared handler state.
+	var counter int
+	ext := makeHandlerExt("shared-state.go", map[EventType][]HandlerFunc{
+		SubagentStart: {
+			func(e Event, c Context) Result {
+				// Read-modify-write: racy without serialization.
+				v := counter
+				counter = v + 1
+				return nil
+			},
+		},
+		SubagentChunk: {
+			func(e Event, c Context) Result {
+				v := counter
+				counter = v + 1
+				return nil
+			},
+		},
+	})
+
+	r := makeRunner(ext)
+	var wg sync.WaitGroup
+	const goroutines = 20
+	const iterations = 50
+	wg.Add(goroutines)
+	for range goroutines {
+		go func() {
+			defer wg.Done()
+			for range iterations {
+				_, _ = r.Emit(SubagentStartEvent{ToolCallID: "x"})
+				_, _ = r.Emit(SubagentChunkEvent{ToolCallID: "x"})
+			}
+		}()
+	}
+	wg.Wait()
+	if counter != goroutines*iterations*2 {
+		t.Errorf("expected counter=%d, got %d (race detected)", goroutines*iterations*2, counter)
+	}
+}
+
+func TestRunner_ConcurrentEmitDifferentExtensions(t *testing.T) {
+	// Two extensions with independent state should not block each other
+	// and should both run correctly under concurrent Emit calls.
+	var counter1, counter2 int
+	ext1 := makeHandlerExt("ext1.go", map[EventType][]HandlerFunc{
+		SubagentStart: {
+			func(e Event, c Context) Result {
+				v := counter1
+				counter1 = v + 1
+				return nil
+			},
+		},
+	})
+	ext2 := makeHandlerExt("ext2.go", map[EventType][]HandlerFunc{
+		SubagentStart: {
+			func(e Event, c Context) Result {
+				v := counter2
+				counter2 = v + 1
+				return nil
+			},
+		},
+	})
+
+	r := makeRunner(ext1, ext2)
+	var wg sync.WaitGroup
+	const goroutines = 20
+	const iterations = 50
+	wg.Add(goroutines)
+	for range goroutines {
+		go func() {
+			defer wg.Done()
+			for range iterations {
+				_, _ = r.Emit(SubagentStartEvent{ToolCallID: "x"})
+			}
+		}()
+	}
+	wg.Wait()
+	expected := goroutines * iterations
+	if counter1 != expected {
+		t.Errorf("ext1 counter: expected %d, got %d", expected, counter1)
+	}
+	if counter2 != expected {
+		t.Errorf("ext2 counter: expected %d, got %d", expected, counter2)
+	}
+}
+
+func TestRunner_ReentrantEmitCustomEvent(t *testing.T) {
+	// Verify that a handler can call EmitCustomEvent (which dispatches to
+	// the same extension's custom event handlers) without deadlocking.
+	var order []string
+	ext := LoadedExtension{
+		Path: "reentrant.go",
+		Handlers: map[EventType][]HandlerFunc{
+			SessionStart: {
+				func(e Event, c Context) Result {
+					order = append(order, "session_start")
+					// This triggers EmitCustomEvent for the same extension
+					// via a direct runner call (simulating ctx.EmitCustomEvent).
+					return nil
+				},
+			},
+		},
+		CustomEventHandlers: map[string][]func(string){
+			"test-event": {
+				func(data string) {
+					order = append(order, "custom:"+data)
+				},
+			},
+		},
+	}
+
+	r := makeRunner(ext)
+
+	// Wire up the handler to call EmitCustomEvent re-entrantly.
+	ext.Handlers[SessionStart] = []HandlerFunc{
+		func(e Event, c Context) Result {
+			order = append(order, "session_start")
+			r.EmitCustomEvent("test-event", "hello")
+			return nil
+		},
+	}
+	r.extensions[0] = ext
+	// Rebuild mutexes after modifying extensions slice.
+	r.extMu = make([]reentrantMu, len(r.extensions))
+	for i := range r.extMu {
+		r.extMu[i].init()
+	}
+
+	_, err := r.Emit(SessionStartEvent{})
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(order) != 2 || order[0] != "session_start" || order[1] != "custom:hello" {
+		t.Errorf("expected [session_start, custom:hello], got %v", order)
+	}
+}

internal/extensions/state_test.go

@@ -0,0 +1,262 @@
+package extensions
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"sync"
+	"testing"
+	"time"
+)
+
+func TestRunner_State_BasicSetGetDelete(t *testing.T) {
+	r := NewRunner(nil)
+
+	if _, ok := r.GetState("missing"); ok {
+		t.Fatal("expected GetState to return ok=false for missing key")
+	}
+
+	r.SetState("a", "1")
+	r.SetState("b", "2")
+	r.SetState("a", "3") // last-write-wins
+
+	if v, ok := r.GetState("a"); !ok || v != "3" {
+		t.Errorf("expected GetState(a)=(3,true), got (%q,%v)", v, ok)
+	}
+	if v, ok := r.GetState("b"); !ok || v != "2" {
+		t.Errorf("expected GetState(b)=(2,true), got (%q,%v)", v, ok)
+	}
+
+	keys := r.ListState()
+	if len(keys) != 2 {
+		t.Errorf("expected 2 keys, got %d (%v)", len(keys), keys)
+	}
+
+	r.DeleteState("a")
+	if _, ok := r.GetState("a"); ok {
+		t.Error("expected key a to be gone after DeleteState")
+	}
+	if len(r.ListState()) != 1 {
+		t.Errorf("expected 1 key after delete, got %v", r.ListState())
+	}
+
+	// Deleting missing key is a no-op.
+	r.DeleteState("never-there")
+}
+
+func TestRunner_State_SaverFires(t *testing.T) {
+	r := NewRunner(nil)
+	var calls int
+	var mu sync.Mutex
+	r.SetStateSaver(func() {
+		mu.Lock()
+		calls++
+		mu.Unlock()
+	})
+
+	r.SetState("a", "1")
+	r.SetState("a", "2")
+	r.DeleteState("a")
+	r.DeleteState("a") // missing → no save
+
+	mu.Lock()
+	defer mu.Unlock()
+	if calls != 3 {
+		t.Errorf("expected saver to fire 3 times (2 sets + 1 delete), got %d", calls)
+	}
+}
+
+func TestRunner_State_SaveAndLoadRoundTrip(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "ext-state.json")
+
+	r1 := NewRunner(nil)
+	r1.SetState("k1", "v1")
+	r1.SetState("k2", `{"json":"value"}`)
+	if err := r1.SaveStateToFile(path); err != nil {
+		t.Fatalf("SaveStateToFile: %v", err)
+	}
+
+	// Verify file contains JSON map.
+	data, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("reading saved file: %v", err)
+	}
+	var parsed map[string]string
+	if err := json.Unmarshal(data, &parsed); err != nil {
+		t.Fatalf("unmarshalling: %v", err)
+	}
+	if parsed["k1"] != "v1" || parsed["k2"] != `{"json":"value"}` {
+		t.Errorf("unexpected file contents: %v", parsed)
+	}
+
+	r2 := NewRunner(nil)
+	if err := r2.LoadStateFromFile(path); err != nil {
+		t.Fatalf("LoadStateFromFile: %v", err)
+	}
+	if v, ok := r2.GetState("k1"); !ok || v != "v1" {
+		t.Errorf("expected k1=v1 after load, got (%q,%v)", v, ok)
+	}
+	if v, ok := r2.GetState("k2"); !ok || v != `{"json":"value"}` {
+		t.Errorf("expected k2 to round-trip, got %q", v)
+	}
+}
+
+func TestRunner_State_LoadMissingFileClearsState(t *testing.T) {
+	// LoadStateFromFile is documented to "replace the in-memory state store
+	// with its contents"; for a missing file that means clearing the store.
+	// This is what makes session-switching safe: a new session that has not
+	// yet written a sidecar must not inherit keys from a prior session.
+	r := NewRunner(nil)
+	r.SetState("a", "1")
+	if err := r.LoadStateFromFile(filepath.Join(t.TempDir(), "does-not-exist.json")); err != nil {
+		t.Errorf("expected nil error for missing file, got %v", err)
+	}
+	if _, ok := r.GetState("a"); ok {
+		t.Error("expected pre-existing state to be cleared when target file is missing")
+	}
+	if keys := r.ListState(); keys != nil {
+		t.Errorf("expected ListState() to be nil after clearing, got %v", keys)
+	}
+}
+
+func TestRunner_State_LoadEmptyFileClearsState(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "empty.json")
+	if err := os.WriteFile(path, nil, 0o644); err != nil {
+		t.Fatal(err)
+	}
+	r := NewRunner(nil)
+	r.SetState("a", "1")
+	if err := r.LoadStateFromFile(path); err != nil {
+		t.Errorf("expected nil error for empty file, got %v", err)
+	}
+	if _, ok := r.GetState("a"); ok {
+		t.Error("expected pre-existing state to be cleared when target file is empty")
+	}
+}
+
+func TestRunner_State_LoadMalformedFileError(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "bad.json")
+	if err := os.WriteFile(path, []byte("{not json"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	r := NewRunner(nil)
+	if err := r.LoadStateFromFile(path); err == nil {
+		t.Error("expected error loading malformed JSON, got nil")
+	}
+}
+
+func TestRunner_State_PersistenceViaSaver(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "ext-state.json")
+
+	r := NewRunner(nil)
+	r.SetStateSaver(func() {
+		_ = r.SaveStateToFile(path)
+	})
+	r.SetState("hello", "world")
+
+	// File should exist with the value already.
+	data, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("reading saved file: %v", err)
+	}
+	var parsed map[string]string
+	if err := json.Unmarshal(data, &parsed); err != nil {
+		t.Fatalf("unmarshalling: %v", err)
+	}
+	if parsed["hello"] != "world" {
+		t.Errorf("expected file to contain hello=world, got %v", parsed)
+	}
+}
+
+func TestRunner_State_ConcurrentSet(t *testing.T) {
+	r := NewRunner(nil)
+	var wg sync.WaitGroup
+	const goroutines = 16
+	const iterations = 100
+	wg.Add(goroutines)
+	for range goroutines {
+		go func() {
+			defer wg.Done()
+			for range iterations {
+				r.SetState("k", "v")
+				_, _ = r.GetState("k")
+			}
+		}()
+	}
+	wg.Wait()
+	if v, ok := r.GetState("k"); !ok || v != "v" {
+		t.Errorf("expected k=v after concurrent writes, got (%q,%v)", v, ok)
+	}
+}
+
+func TestRunner_State_ContextNoOpsWhenUnset(t *testing.T) {
+	// Verify normalizeContext installs safe no-ops for SetState/GetState/etc.
+	// when not provided by the caller.
+	ext := makeHandlerExt("state.go", map[EventType][]HandlerFunc{
+		SessionStart: {
+			func(e Event, c Context) Result {
+				// All four state functions should be non-nil and safe to call.
+				c.SetState("a", "b")
+				if v, ok := c.GetState("a"); ok || v != "" {
+					t.Errorf("no-op GetState should return (\"\", false); got (%q,%v)", v, ok)
+				}
+				c.DeleteState("a")
+				if keys := c.ListState(); keys != nil {
+					t.Errorf("no-op ListState should return nil; got %v", keys)
+				}
+				return nil
+			},
+		},
+	})
+	r := makeRunner(ext)
+	// SetContext with empty Context to exercise normalizeContext defaults.
+	r.SetContext(Context{})
+	_, err := r.Emit(SessionStartEvent{})
+	if err != nil {
+		t.Fatalf("emit: %v", err)
+	}
+}
+
+func TestRunner_State_SaverPanicReleasesSaverMu(t *testing.T) {
+	// If the saver callback panics (e.g. disk full mid-write), runSaver
+	// must still release saverMu so subsequent SetState/DeleteState calls
+	// can make progress. Without `defer Unlock()` the lock would be
+	// permanently held and the next write would deadlock.
+	r := NewRunner(nil)
+	var calls int
+	r.SetStateSaver(func() {
+		calls++
+		if calls == 1 {
+			panic("simulated disk-write failure")
+		}
+	})
+
+	// First call panics. Recover, then verify a follow-up call still works
+	// without blocking (proving saverMu was released).
+	func() {
+		defer func() {
+			if rec := recover(); rec == nil {
+				t.Fatal("expected panic from first saver invocation")
+			}
+		}()
+		r.SetState("a", "1")
+	}()
+
+	done := make(chan struct{})
+	go func() {
+		r.SetState("b", "2") // would deadlock if saverMu were still held
+		close(done)
+	}()
+	select {
+	case <-done:
+	case <-time.After(2 * time.Second):
+		t.Fatal("SetState after saver panic blocked — saverMu was not released")
+	}
+	if calls != 2 {
+		t.Errorf("expected saver to fire twice (panic + recovery write), got %d", calls)
+	}
+}

internal/extensions/subagent.go

@@ -2,22 +2,15 @@
 package extensions
 
 import (
-	"bufio"
-	"context"
-	"encoding/json"
 	"fmt"
 	"os"
-	"os/exec"
-	"strings"
 	"sync"
-	"sync/atomic"
 	"time"
 )
 
 // ---------------------------------------------------------------------------
 // Subagent types
 // ---------------------------------------------------------------------------
-
 // SubagentConfig configures a subagent spawn.
 type SubagentConfig struct {
 	// Prompt is the task/instruction for the subagent (required).
@@ -157,221 +150,3 @@ func (h *SubagentHandle) Wait() SubagentResult {
 func (h *SubagentHandle) Done() <-chan struct{} {
 	return h.done
 }
-
-// ---------------------------------------------------------------------------
-// Internal helpers
-// ---------------------------------------------------------------------------
-
-// subagentJSONOutput matches the JSON envelope produced by `kit --json`.
-type subagentJSONOutput struct {
-	Response   string `json:"response"`
-	StopReason string `json:"stop_reason,omitempty"`
-	SessionID  string `json:"session_id,omitempty"`
-	Usage      *struct {
-		InputTokens  int64 `json:"input_tokens"`
-		OutputTokens int64 `json:"output_tokens"`
-	} `json:"usage,omitempty"`
-}
-
-var subagentCounter uint64
-
-func generateSubagentID() string {
-	n := atomic.AddUint64(&subagentCounter, 1)
-	return fmt.Sprintf("sub-%d-%d", time.Now().UnixNano(), n)
-}
-
-func findKitBinary() string {
-	// Try the current process executable first.
-	if exe, err := os.Executable(); err == nil {
-		if _, err := os.Stat(exe); err == nil {
-			return exe
-		}
-	}
-	// Fall back to PATH lookup.
-	if p, err := exec.LookPath("kit"); err == nil {
-		return p
-	}
-	return "kit"
-}
-
-// ---------------------------------------------------------------------------
-// SpawnSubagent implementation
-// ---------------------------------------------------------------------------
-
-// SpawnSubagent spawns a child Kit instance to perform a task.
-//
-// When config.Blocking is true, blocks until completion and returns the result
-// directly (handle is nil). When false, returns immediately with a handle for
-// monitoring/cancellation.
-//
-// The subagent runs with --json --no-session --no-extensions flags by default,
-// ensuring isolation from the parent's extensions and session state.
-func SpawnSubagent(cfg SubagentConfig) (*SubagentHandle, *SubagentResult, error) {
-	if cfg.Prompt == "" {
-		return nil, nil, fmt.Errorf("prompt is required")
-	}
-
-	timeout := cfg.Timeout
-	if timeout == 0 {
-		timeout = 5 * time.Minute
-	}
-
-	kitBinary := findKitBinary()
-
-	// Build subprocess arguments.
-	args := []string{
-		"--json",
-		"--no-extensions",
-	}
-	if cfg.NoSession {
-		args = append(args, "--no-session")
-	}
-	if cfg.Model != "" {
-		args = append(args, "--model", cfg.Model)
-	}
-
-	// Handle system prompt - write to temp file if provided.
-	var tmpFile *os.File
-	if cfg.SystemPrompt != "" {
-		var err error
-		tmpFile, err = os.CreateTemp("", "kit-subagent-*.txt")
-		if err != nil {
-			return nil, nil, fmt.Errorf("create temp file: %w", err)
-		}
-		if _, err := tmpFile.WriteString(cfg.SystemPrompt); err != nil {
-			_ = tmpFile.Close()
-			_ = os.Remove(tmpFile.Name())
-			return nil, nil, fmt.Errorf("write system prompt: %w", err)
-		}
-		_ = tmpFile.Close()
-		args = append(args, "--system-prompt", tmpFile.Name())
-	}
-
-	// Add the prompt as a positional argument.
-	args = append(args, cfg.Prompt)
-
-	// Create command with timeout context.
-	ctx, cancel := context.WithTimeout(context.Background(), timeout)
-
-	cmd := exec.CommandContext(ctx, kitBinary, args...)
-	cmd.Env = os.Environ()
-
-	stdout, err := cmd.StdoutPipe()
-	if err != nil {
-		cancel()
-		if tmpFile != nil {
-			_ = os.Remove(tmpFile.Name())
-		}
-		return nil, nil, fmt.Errorf("stdout pipe: %w", err)
-	}
-	stderr, err := cmd.StderrPipe()
-	if err != nil {
-		cancel()
-		if tmpFile != nil {
-			_ = os.Remove(tmpFile.Name())
-		}
-		return nil, nil, fmt.Errorf("stderr pipe: %w", err)
-	}
-
-	handle := &SubagentHandle{
-		ID:   generateSubagentID(),
-		done: make(chan struct{}),
-	}
-
-	// Start the subprocess.
-	start := time.Now()
-	if err := cmd.Start(); err != nil {
-		cancel()
-		if tmpFile != nil {
-			_ = os.Remove(tmpFile.Name())
-		}
-		return nil, nil, fmt.Errorf("start subprocess: %w", err)
-	}
-
-	handle.mu.Lock()
-	handle.proc = cmd.Process
-	handle.mu.Unlock()
-
-	// Run the subprocess monitoring in a goroutine.
-	go func() {
-		defer close(handle.done)
-		defer cancel()
-		if tmpFile != nil {
-			defer func() { _ = os.Remove(tmpFile.Name()) }()
-		}
-
-		var wg sync.WaitGroup
-		var stdoutBuf strings.Builder
-
-		// Read stderr (live output).
-		wg.Go(func() {
-			scanner := bufio.NewScanner(stderr)
-			scanner.Buffer(make([]byte, 256*1024), 256*1024)
-			for scanner.Scan() {
-				line := scanner.Text()
-				if cfg.OnOutput != nil && strings.TrimSpace(line) != "" {
-					cfg.OnOutput(line + "\n")
-				}
-			}
-		})
-
-		// Read stdout (JSON output).
-		scanner := bufio.NewScanner(stdout)
-		scanner.Buffer(make([]byte, 256*1024), 256*1024)
-		for scanner.Scan() {
-			stdoutBuf.WriteString(scanner.Text() + "\n")
-		}
-
-		wg.Wait()
-		waitErr := cmd.Wait()
-		elapsed := time.Since(start)
-
-		// Build result.
-		result := SubagentResult{Elapsed: elapsed}
-		if waitErr != nil {
-			result.Error = waitErr
-			if exitErr, ok := waitErr.(*exec.ExitError); ok {
-				result.ExitCode = exitErr.ExitCode()
-			} else {
-				result.ExitCode = 1
-			}
-		}
-
-		// Parse JSON output.
-		raw := strings.TrimSpace(stdoutBuf.String())
-		var parsed subagentJSONOutput
-		if raw != "" && json.Unmarshal([]byte(raw), &parsed) == nil {
-			result.Response = parsed.Response
-			result.SessionID = parsed.SessionID
-			if parsed.Usage != nil {
-				result.Usage = &SubagentUsage{
-					InputTokens:  parsed.Usage.InputTokens,
-					OutputTokens: parsed.Usage.OutputTokens,
-				}
-			}
-		} else {
-			// Fallback: use raw stdout.
-			result.Response = raw
-		}
-
-		handle.mu.Lock()
-		handle.result = &result
-		handle.proc = nil
-		handle.mu.Unlock()
-
-		if cfg.OnComplete != nil {
-			cfg.OnComplete(result)
-		}
-	}()
-
-	if cfg.Blocking {
-		// Wait for completion and return result directly.
-		<-handle.done
-		handle.mu.Lock()
-		r := handle.result
-		handle.mu.Unlock()
-		return nil, r, nil
-	}
-
-	return handle, nil, nil
-}

internal/extensions/symbols.go

@@ -31,6 +31,7 @@ func Symbols() interp.Exports {
 			// Session types
 			"SessionMessage": reflect.ValueOf((*SessionMessage)(nil)),
 			"ExtensionEntry": reflect.ValueOf((*ExtensionEntry)(nil)),
+			"SessionUsage":   reflect.ValueOf((*SessionUsage)(nil)),
 
 			// Option types
 			"OptionDef": reflect.ValueOf((*OptionDef)(nil)),
@@ -44,6 +45,8 @@ func Symbols() interp.Exports {
 			// LLM completion types
 			"CompleteRequest":  reflect.ValueOf((*CompleteRequest)(nil)),
 			"CompleteResponse": reflect.ValueOf((*CompleteResponse)(nil)),
+			"CompactConfig":    reflect.ValueOf((*CompactConfig)(nil)),
+			"FilePart":         reflect.ValueOf((*FilePart)(nil)),
 
 			// Status bar types
 			"StatusBarEntry": reflect.ValueOf((*StatusBarEntry)(nil)),
@@ -119,13 +122,39 @@ func Symbols() interp.Exports {
 			"SubagentHandle": reflect.ValueOf((*SubagentHandle)(nil)),
 			"SubagentEvent":  reflect.ValueOf((*SubagentEvent)(nil)),
 
+			// Subagent lifecycle events
+			"SubagentStartEvent": reflect.ValueOf((*SubagentStartEvent)(nil)),
+			"SubagentChunkEvent": reflect.ValueOf((*SubagentChunkEvent)(nil)),
+			"SubagentEndEvent":   reflect.ValueOf((*SubagentEndEvent)(nil)),
+
 			// Theme types
 			"ThemeColor":       reflect.ValueOf((*ThemeColor)(nil)),
 			"ThemeColorConfig": reflect.ValueOf((*ThemeColorConfig)(nil)),
 
+			// Tree navigation types
+			"TreeNode":             reflect.ValueOf((*TreeNode)(nil)),
+			"TreeNavigationResult": reflect.ValueOf((*TreeNavigationResult)(nil)),
+
+			// Skill types
+			"Skill":           reflect.ValueOf((*Skill)(nil)),
+			"SkillLoadResult": reflect.ValueOf((*SkillLoadResult)(nil)),
+
+			// Template parsing types
+			"PromptTemplate":   reflect.ValueOf((*PromptTemplate)(nil)),
+			"ArgumentPattern":  reflect.ValueOf((*ArgumentPattern)(nil)),
+			"ParseResult":      reflect.ValueOf((*ParseResult)(nil)),
+			"ModelConditional": reflect.ValueOf((*ModelConditional)(nil)),
+
+			// Model resolution types
+			"ModelCapabilities":     reflect.ValueOf((*ModelCapabilities)(nil)),
+			"ModelResolutionResult": reflect.ValueOf((*ModelResolutionResult)(nil)),
+
 			// Event structs
 			"ToolCallEvent":           reflect.ValueOf((*ToolCallEvent)(nil)),
 			"ToolCallResult":          reflect.ValueOf((*ToolCallResult)(nil)),
+			"ToolCallInputStartEvent": reflect.ValueOf((*ToolCallInputStartEvent)(nil)),
+			"ToolCallInputDeltaEvent": reflect.ValueOf((*ToolCallInputDeltaEvent)(nil)),
+			"ToolCallInputEndEvent":   reflect.ValueOf((*ToolCallInputEndEvent)(nil)),
 			"ToolExecutionStartEvent": reflect.ValueOf((*ToolExecutionStartEvent)(nil)),
 			"ToolExecutionEndEvent":   reflect.ValueOf((*ToolExecutionEndEvent)(nil)),
 			"ToolOutputEvent":         reflect.ValueOf((*ToolOutputEvent)(nil)),
@@ -143,6 +172,18 @@ func Symbols() interp.Exports {
 			"SessionStartEvent":       reflect.ValueOf((*SessionStartEvent)(nil)),
 			"SessionShutdownEvent":    reflect.ValueOf((*SessionShutdownEvent)(nil)),
 			"ModelChangeEvent":        reflect.ValueOf((*ModelChangeEvent)(nil)),
+
+			// Step lifecycle events
+			"StepStartEvent":      reflect.ValueOf((*StepStartEvent)(nil)),
+			"StepFinishEvent":     reflect.ValueOf((*StepFinishEvent)(nil)),
+			"ReasoningStartEvent": reflect.ValueOf((*ReasoningStartEvent)(nil)),
+			"WarningsEvent":       reflect.ValueOf((*WarningsEvent)(nil)),
+			"SourceEvent":         reflect.ValueOf((*SourceEvent)(nil)),
+			"ErrorEvent":          reflect.ValueOf((*ErrorEvent)(nil)),
+			"RetryEvent":          reflect.ValueOf((*RetryEvent)(nil)),
+			"PrepareStepEvent":    reflect.ValueOf((*PrepareStepEvent)(nil)),
+			"PrepareStepResult":   reflect.ValueOf((*PrepareStepResult)(nil)),
+			"LLMUsageEvent":       reflect.ValueOf((*LLMUsageEvent)(nil)),
 		},
 	}
 }

internal/extensions/test_api.go

@@ -171,5 +171,29 @@ func NewTestAPI(ext *LoadedExtension) API {
 		registerMessageRendererFn: func(config MessageRendererConfig) {
 			ext.MessageRenderers = append(ext.MessageRenderers, config)
 		},
+		onSubagentStart: func(h func(SubagentStartEvent, Context)) {
+			reg(SubagentStart, func(e Event, c Context) Result {
+				h(e.(SubagentStartEvent), c)
+				return nil
+			})
+		},
+		onSubagentChunk: func(h func(SubagentChunkEvent, Context)) {
+			reg(SubagentChunk, func(e Event, c Context) Result {
+				h(e.(SubagentChunkEvent), c)
+				return nil
+			})
+		},
+		onSubagentEnd: func(h func(SubagentEndEvent, Context)) {
+			reg(SubagentEnd, func(e Event, c Context) Result {
+				h(e.(SubagentEndEvent), c)
+				return nil
+			})
+		},
+		onLLMUsage: func(h func(LLMUsageEvent, Context)) {
+			reg(LLMUsage, func(e Event, c Context) Result {
+				h(e.(LLMUsageEvent), c)
+				return nil
+			})
+		},
 	}
 }

internal/extensions/toolkinds.go

@@ -0,0 +1,38 @@
+package extensions
+
+// ToolKind constants classify what a tool does, enabling UIs to render
+// appropriate visualizations (e.g. diff view for edit tools, command+output
+// for execute tools) and file trackers to identify which results contain
+// modifications.
+//
+// This is the single source of truth for tool-kind classification; the
+// pkg/kit SDK re-exports these constants.
+const (
+	ToolKindExecute  = "execute" // Shell execution (bash)
+	ToolKindEdit     = "edit"    // File modification (edit, write)
+	ToolKindRead     = "read"    // File reading (read, ls)
+	ToolKindSearch   = "search"  // Content/file search (grep, find)
+	ToolKindSubagent = "agent"   // Subagent spawning (subagent)
+)
+
+// coreToolKinds maps built-in tool names to their kind classification.
+// MCP and extension tools without an entry default to ToolKindExecute.
+var coreToolKinds = map[string]string{
+	"bash":     ToolKindExecute,
+	"edit":     ToolKindEdit,
+	"write":    ToolKindEdit,
+	"read":     ToolKindRead,
+	"ls":       ToolKindRead,
+	"grep":     ToolKindSearch,
+	"find":     ToolKindSearch,
+	"subagent": ToolKindSubagent,
+}
+
+// ToolKindFor returns the ToolKind for a given tool name, defaulting to
+// ToolKindExecute for unknown tools (including MCP tools).
+func ToolKindFor(toolName string) string {
+	if kind, ok := coreToolKinds[toolName]; ok {
+		return kind
+	}
+	return ToolKindExecute
+}

internal/extensions/watcher.go

@@ -0,0 +1,59 @@
+package extensions
+
+import (
+	"os"
+	"path/filepath"
+
+	"github.com/mark3labs/kit/internal/watcher"
+)
+
+// Watcher monitors extension directories for .go file changes and triggers
+// a reload callback when changes are detected. It is implemented in terms
+// of the general-purpose internal/watcher.ContentWatcher.
+//
+// Type-aliasing here lets existing call sites (cmd/root.go and the
+// watcher_test.go suite) keep using `extensions.NewWatcher` / `*Watcher`
+// without knowing about the underlying implementation.
+type Watcher = watcher.ContentWatcher
+
+// NewWatcher creates a file watcher that monitors the given directories
+// for .go file changes. When a change is detected (after debouncing),
+// onReload is called. The watcher must be started with Start() and
+// stopped with Close().
+func NewWatcher(dirs []string, onReload func()) (*Watcher, error) {
+	return watcher.New(watcher.Options{
+		Dirs:       dirs,
+		Extensions: []string{".go"},
+		OnReload:   onReload,
+		Label:      "extensions",
+	})
+}
+
+// WatchedDirs returns the directories to watch for extension changes.
+// This includes the global extensions directory and the project-local
+// .kit/extensions/ directory (if they exist). Explicit -e paths that
+// point to directories are also included; explicit file paths cause
+// their parent directory to be watched instead.
+func WatchedDirs(extraPaths []string) []string {
+	standard := []string{
+		globalExtensionsDir(),
+		filepath.Join(".kit", "extensions"),
+	}
+
+	// Filter explicit paths into directories (passed through) and files
+	// (parent dir watched) for CollectDirs to dedupe.
+	var extras []string
+	for _, p := range extraPaths {
+		info, err := os.Stat(p)
+		if err != nil {
+			continue
+		}
+		if info.IsDir() {
+			extras = append(extras, p)
+		} else {
+			extras = append(extras, filepath.Dir(p))
+		}
+	}
+
+	return watcher.CollectDirs(standard, extras)
+}