feat(ui): add bordered container and improved styling to session selector

- Add full-width bordered container with rounded border and primary color
- Add max height constraint to prevent terminal overflow
- Improve selection highlighting with inverted colors matching PopupList style
- Change cursor indicator from › to > for consistency
- Add separator lines between header, content, and footer
- Add footer showing current filter mode

.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

@@ -28,11 +28,15 @@ type lintResult struct {
 	Err    error
 }
 
+// Package-level state: set of .go files edited during the current agent turn.
+var editedFiles map[string]bool
+
 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")
+		ctx.Print("go-edit-lint extension loaded - will run gopls and golangci-lint after agent turns that edit Go files")
 	})
 
+	// Track edited .go files — don't lint yet.
 	api.OnToolResult(func(e ext.ToolResultEvent, ctx ext.Context) *ext.ToolResultResult {
 		if e.IsError || !isEditOrWrite(e.ToolName) {
 			return nil
@@ -43,30 +47,72 @@ func Init(api ext.API) {
 			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
+		if editedFiles == nil {
+			editedFiles = make(map[string]bool)
+		}
+		editedFiles[absPath] = true
+		return nil
+	})
+
+	// After the agent turn ends, lint all collected files.
+	api.OnAgentEnd(func(e ext.AgentEndEvent, ctx ext.Context) {
+		if len(editedFiles) == 0 {
+			return
 		}
 
-		// Show TUI message block for diagnostics visibility (only if there are issues)
+		// Snapshot and reset immediately so the next turn starts clean.
+		files := editedFiles
+		editedFiles = nil
+
+		// Skip lint on errored turns.
+		if e.StopReason == "error" {
+			return
+		}
+
+		// Collect unique directories and file list for gopls.
+		var allGoplsOutput []string
+		for absPath := range files {
+			res := runGopls(ctx.CWD, absPath)
+			formatted := formatToolResult(res, "")
+			if formatted != "" {
+				allGoplsOutput = append(allGoplsOutput, fmt.Sprintf("# %s\n%s", filepath.Base(absPath), formatted))
+			}
+		}
+
+		lintRes := runGolangCILint(ctx.CWD, "./...")
+
+		goplsSection := "No diagnostics."
+		if len(allGoplsOutput) > 0 {
+			goplsSection = strings.Join(allGoplsOutput, "\n\n")
+		}
+		lintSection := formatToolResult(lintRes, "No lint issues.")
+
+		// Build file list for the report header.
+		var fileNames []string
+		for absPath := range files {
+			fileNames = append(fileNames, filepath.Base(absPath))
+		}
+
+		report := fmt.Sprintf(
+			"<go_diagnostics files=%q>\n[gopls]\n%s\n\n[golangci-lint]\n%s\n</go_diagnostics>",
+			strings.Join(fileNames, ", "),
+			goplsSection,
+			lintSection,
+		)
+
+		goplsIssues, lintIssues := countIssues(report)
+		hasIssues := goplsIssues > 0 || lintIssues > 0
+
 		if hasIssues {
+			// Show TUI block so the user sees it too.
 			var msgLines []string
-			msgLines = append(msgLines, fmt.Sprintf("File: %s", filepath.Base(absPath)))
+			msgLines = append(msgLines, fmt.Sprintf("Files: %s", strings.Join(fileNames, ", ")))
 			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 {
@@ -78,9 +124,16 @@ func Init(api ext.API) {
 				BorderColor: borderColor,
 				Subtitle:    "go-edit-lint",
 			})
-		}
 
-		return &ext.ToolResultResult{Content: &enhanced}
+			// Inject a follow-up message so the agent fixes the issues.
+			ctx.SendMessage(report + "\n\n⚠️ DIAGNOSTICS FOUND: Please review and fix the issues above.")
+		} else {
+			ctx.PrintBlock(ext.PrintBlockOpts{
+				Text:        fmt.Sprintf("Files: %s\n✓ All clean", strings.Join(fileNames, ", ")),
+				BorderColor: "#a6e3a1",
+				Subtitle:    "go-edit-lint",
+			})
+		}
 	})
 }
 
@@ -106,18 +159,6 @@ func resolveGoFilePath(inputJSON, cwd string) (string, bool) {
 	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()
@@ -178,7 +219,9 @@ func formatToolResult(res lintResult, emptyFallback string) string {
 	out := strings.TrimSpace(res.Output)
 	if out == "" {
 		if res.Err == nil {
-			lines = append(lines, emptyFallback)
+			if emptyFallback != "" {
+				lines = append(lines, emptyFallback)
+			}
 		}
 	} else {
 		lines = append(lines, out)
@@ -197,17 +240,15 @@ func truncate(s string, max int) string {
 }
 
 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." {
+			if line != "" && line != "[gopls]" && line != "No diagnostics." && !strings.HasPrefix(line, "#") {
 				goplsCount++
 			}
 		}
@@ -215,7 +256,6 @@ func countIssues(report string) (goplsCount, lintCount int) {
 
 	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." {

.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/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/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: $@
+
+## Feature Request Template
+
+This prompt uses the `feature_request` GitHub template which requires:
+
+| Field | Required | Purpose |
+|-------|----------|---------|
+| **Feature Description** | Yes | What should be added or changed |
+| **Motivation / Use Case** | Yes | Why is this needed? What problem does it solve? |
+| **Proposed Implementation** | No | How do you think this should work? |
+
+## Steps
+
+1. **Understand the request** from `$@`
+   - 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: $@
+
+## Issue Templates Available
+
+This repository has structured issue templates. You MUST use the appropriate template:
+
+| Type | Template | Use For |
+|------|----------|---------|
+| `bug` | `bug_report` | Something is broken, not working as expected |
+| `feat` | `feature_request` | New feature, enhancement, improvement |
+| `docs` | `documentation` | Missing, incorrect, or unclear documentation |
+
+## Steps
+
+1. **Determine the issue type** from `$@`:
+   - 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/new-prompt.md

@@ -0,0 +1,47 @@
+---
+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. Use $@ for all user-supplied arguments,
+$1 $2 etc. for positional arguments.
+```
+
+- **Filename** → slug: `commit-push.md` becomes `/commit-push`
+- **Frontmatter**: only `description` is recognised; keep it under ~80 chars
+- **Body**: plain markdown; the full text is submitted as the user's message when the template fires
+- **Arguments**: `$@` expands to everything the user typed after the slash command name;
+  `$1`, `$2` for individual positional args; omit entirely if no arguments are needed
+
+## Steps
+
+1. **Understand the workflow** the user described in `$@` — 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. **Draft the body**:
+   - Open with a single sentence stating the goal
+   - Use `## Steps` for multi-step workflows; use plain prose for simple prompts
+   - Be specific: name commands, flags, and file paths where relevant
+   - End with `$@` on its own line if the user might want to pass context or a hint; omit if the prompt is self-contained
+5. **Write the file** to `.kit/prompts/<slug>.md`
+6. **Confirm** by showing the final file content and the slash command that activates it
+
+## 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

.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.
+
+---
+
+$@

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

AUTOSCROLL_FIX_SUMMARY.md

@@ -0,0 +1,80 @@
+# Autoscroll Fix - Final Summary
+
+## Root Cause
+
+The autoscroll was failing for streaming assistant messages due to a bug in how `GotoBottom()` calculated item heights.
+
+### The Problem
+
+1. **Reasoning blocks** (`StreamingMessageItem` with `role="reasoning"`) are **never cached** because they have live duration counters that update every render
+2. The `Height()` method returns `0` when `cachedRender == ""`
+3. `GotoBottom()` was calling:
+   ```go
+   itemHeight := item.Height()  // Returns 0 for reasoning
+   if itemHeight == 0 {
+       item.Render(s.width)  // Renders but doesn't cache (reasoning)
+       itemHeight = item.Height()  // Still returns 0!
+   }
+   ```
+4. This caused incorrect scroll position calculations, especially during reasoning → assistant transitions
+
+## The Solution
+
+Changed `GotoBottom()` and `AtBottom()` to calculate height **directly from the rendered string** instead of relying on the cached height:
+
+```go
+// OLD: item.Height() which checks cached render
+itemHeight := item.Height()
+if itemHeight == 0 {
+    item.Render(s.width)
+    itemHeight = item.Height()  // Still might be 0!
+}
+
+// NEW: Calculate from rendered string directly
+rendered := item.Render(s.width)
+itemHeight := strings.Count(rendered, "\n") + 1
+```
+
+This works for **all** items regardless of whether they cache their render or not.
+
+## Files Changed
+
+### `internal/ui/scrolllist.go`
+- **`GotoBottom()`**: Calculate height from rendered string (2 loops)
+- **`AtBottom()`**: Calculate height from rendered string (1 loop)
+
+### `internal/ui/model.go`
+- **`appendStreamingChunk()`**: For existing messages, call `GotoBottom()` directly (iteratr pattern)
+- **`refreshContent()`**: Simplified to only call `SetItems()` (removed redundant `GotoBottom()`)
+- **Bash streaming handler**: Removed redundant `GotoBottom()` after `refreshContent()`
+
+## Testing Results
+
+✅ **Test prompt**: "explore this repo"
+
+**Before fix**:
+- Autoscroll stopped after reasoning block completed
+- Viewport stuck showing end of reasoning ("Thought for 203ms")
+- Assistant response streamed off-screen below
+
+**After fix**:
+- Autoscroll works throughout reasoning block
+- Autoscroll continues during reasoning → assistant transition  
+- Viewport stays at bottom showing latest assistant content
+- Final position shows end of response (build commands section)
+
+## Behavior Verified
+
+1. ✅ Streaming text auto-scrolls to bottom
+2. ✅ Works across reasoning → assistant transition
+3. ✅ Manual scroll up (PgUp) disables autoscroll
+4. ✅ Scroll to bottom (Alt+End) re-enables autoscroll
+5. ✅ Accurate positioning with no offset errors
+
+## Performance Note
+
+The fix calls `Render()` on all items during `GotoBottom()` calculations. This is acceptable because:
+- `Render()` is already optimized with caching for non-reasoning items
+- `GotoBottom()` is only called during content updates (not every frame)
+- Reasoning blocks need to render anyway for live duration updates
+- This matches iteratr's approach of ensuring items are rendered before height calculations

README.md

@@ -18,7 +18,7 @@ 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, read, write, edit, grep, find, ls, subagent - no MCP overhead
 - **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
@@ -209,7 +209,7 @@ kit auth status              # Check authentication status
 
 # 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
@@ -477,7 +477,7 @@ 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 |
 
 ## Go SDK
@@ -502,7 +502,7 @@ 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?")
@@ -543,23 +543,26 @@ host, err := kit.New(ctx, &kit.Options{
 ### 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.OnStreaming(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)
-    },
 )
 ```
 
@@ -723,7 +726,7 @@ 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

btca.config.jsonc

@@ -82,6 +82,12 @@
       "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/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/root.go

@@ -10,8 +10,6 @@ import (
 	"strings"
 
 	tea "charm.land/bubbletea/v2"
-	"charm.land/fantasy"
-	"charm.land/lipgloss/v2"
 	"github.com/mark3labs/kit/internal/app"
 	"github.com/mark3labs/kit/internal/auth"
 	"github.com/mark3labs/kit/internal/config"
@@ -19,6 +17,7 @@ import (
 	"github.com/mark3labs/kit/internal/models"
 	"github.com/mark3labs/kit/internal/prompts"
 	"github.com/mark3labs/kit/internal/ui"
+	"github.com/mark3labs/kit/internal/ui/commands"
 	kit "github.com/mark3labs/kit/pkg/kit"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
@@ -38,7 +37,6 @@ var (
 	noExitFlag       bool
 	maxSteps         int
 	streamFlag       bool // Enable streaming output
-	compactMode      bool // Enable compact output mode
 	autoCompactFlag  bool // Enable auto-compaction near context limit
 
 	// Session management
@@ -219,29 +217,10 @@ func configToUiTheme(cfg config.Theme) ui.Theme {
 	}
 }
 
-// kitBanner returns the KIT ASCII art title with KITT scanner lights,
-// rendered with a KITT red gradient.
+// kitBanner returns the KIT ASCII art title with KITT scanner lights.
+// Delegates to ui.KitBanner() which owns the logo rendering.
 func kitBanner() string {
-	kittDark := lipgloss.Color("#8B0000")
-	kittBright := lipgloss.Color("#FF2200")
-	lines := []string{
-		"            ██╗  ██╗ ██╗ ████████╗",
-		"            ██║ ██╔╝ ██║ ╚══██╔══╝",
-		"            █████╔╝  ██║    ██║",
-		"            ██╔═██╗  ██║    ██║",
-		"            ██║  ██╗ ██║    ██║",
-		"            ╚═╝  ╚═╝ ╚═╝    ╚═╝",
-		" ░░░░░░▒▒▒▒▒▓▓▓▓███████████████▓▓▓▓▒▒▒▒▒░░░░░░",
-	}
-
-	var result strings.Builder
-	for i, line := range lines {
-		if i > 0 {
-			result.WriteString("\n")
-		}
-		result.WriteString(ui.ApplyGradient(line, kittDark, kittBright))
-	}
-	return result.String()
+	return ui.KitBanner()
 }
 
 func init() {
@@ -280,8 +259,6 @@ func init() {
 		IntVar(&maxSteps, "max-steps", 0, "maximum number of agent steps (0 for unlimited)")
 	rootCmd.PersistentFlags().
 		BoolVar(&streamFlag, "stream", true, "enable streaming output for faster response display")
-	rootCmd.PersistentFlags().
-		BoolVar(&compactMode, "compact", false, "enable compact output mode without fancy styling")
 	rootCmd.PersistentFlags().
 		BoolVar(&autoCompactFlag, "auto-compact", false, "auto-compact conversation when near context limit")
 	rootCmd.PersistentFlags().
@@ -325,7 +302,6 @@ func init() {
 	_ = viper.BindPFlag("debug", rootCmd.PersistentFlags().Lookup("debug"))
 	_ = viper.BindPFlag("max-steps", rootCmd.PersistentFlags().Lookup("max-steps"))
 	_ = viper.BindPFlag("stream", rootCmd.PersistentFlags().Lookup("stream"))
-	_ = viper.BindPFlag("compact", rootCmd.PersistentFlags().Lookup("compact"))
 	_ = viper.BindPFlag("auto-compact", rootCmd.PersistentFlags().Lookup("auto-compact"))
 
 	_ = viper.BindPFlag("provider-url", rootCmd.PersistentFlags().Lookup("provider-url"))
@@ -411,30 +387,30 @@ func runKit(ctx context.Context) error {
 }
 
 // extensionCommandsForUI converts extension-registered CommandDefs into the
-// ui.ExtensionCommand type used by the interactive TUI. Command names are
+// commands.ExtensionCommand type used by the interactive TUI. Command names are
 // normalised to start with "/" so they integrate with the slash-command
 // autocomplete and dispatch pipeline.
-func extensionCommandsForUI(k *kit.Kit) []ui.ExtensionCommand {
-	defs := k.ExtensionCommands()
+func extensionCommandsForUI(k *kit.Kit) []commands.ExtensionCommand {
+	defs := k.Extensions().Commands()
 	if len(defs) == 0 {
 		return nil
 	}
-	cmds := make([]ui.ExtensionCommand, 0, len(defs))
+	cmds := make([]commands.ExtensionCommand, 0, len(defs))
 	for _, d := range defs {
 		name := d.Name
 		if len(name) > 0 && name[0] != '/' {
 			name = "/" + name
 		}
-		ec := ui.ExtensionCommand{
+		ec := commands.ExtensionCommand{
 			Name:        name,
 			Description: d.Description,
 			Execute: func(args string) (string, error) {
-				return d.Execute(args, k.GetExtensionContext())
+				return d.Execute(args, k.Extensions().GetContext())
 			},
 		}
 		if d.Complete != nil {
 			ec.Complete = func(prefix string) []string {
-				return d.Complete(prefix, k.GetExtensionContext())
+				return d.Complete(prefix, k.Extensions().GetContext())
 			}
 		}
 		cmds = append(cmds, ec)
@@ -446,11 +422,11 @@ func extensionCommandsForUI(k *kit.Kit) []ui.ExtensionCommand {
 // ui.WidgetData for the given placement. Returns nil if extensions are
 // disabled, which is safe — the UI treats a nil GetWidgets as "no widgets".
 func widgetProviderForUI(k *kit.Kit) func(string) []ui.WidgetData {
-	if !k.HasExtensions() {
+	if !k.Extensions().HasExtensions() {
 		return nil
 	}
 	return func(placement string) []ui.WidgetData {
-		configs := k.GetExtensionWidgets(extensions.WidgetPlacement(placement))
+		configs := k.Extensions().GetWidgets(extensions.WidgetPlacement(placement))
 		if len(configs) == 0 {
 			return nil
 		}
@@ -467,25 +443,34 @@ func widgetProviderForUI(k *kit.Kit) func(string) []ui.WidgetData {
 	}
 }
 
+// headerFooterProviderForUI returns a provider func that maps an
+// extensions.HeaderFooterConfig getter into the ui.WidgetData shape
+// expected by AppModel. The getter argument selects header vs footer.
+func headerFooterProviderForUI(k *kit.Kit, getter func() *extensions.HeaderFooterConfig) func() *ui.WidgetData {
+	if !k.Extensions().HasExtensions() {
+		return nil
+	}
+	return func() *ui.WidgetData {
+		cfg := getter()
+		if cfg == nil {
+			return nil
+		}
+		return &ui.WidgetData{
+			Text:        cfg.Content.Text,
+			Markdown:    cfg.Content.Markdown,
+			BorderColor: cfg.Style.BorderColor,
+			NoBorder:    cfg.Style.NoBorder,
+		}
+	}
+}
+
 // headerProviderForUI returns a function that converts the extension header
 // to a *ui.WidgetData for the TUI. Returns nil if extensions are disabled,
 // which is safe — the UI treats a nil GetHeader as "no header".
 func headerProviderForUI(k *kit.Kit) func() *ui.WidgetData {
-	if !k.HasExtensions() {
-		return nil
-	}
-	return func() *ui.WidgetData {
-		config := k.GetExtensionHeader()
-		if config == nil {
-			return nil
-		}
-		return &ui.WidgetData{
-			Text:        config.Content.Text,
-			Markdown:    config.Content.Markdown,
-			BorderColor: config.Style.BorderColor,
-			NoBorder:    config.Style.NoBorder,
-		}
-	}
+	return headerFooterProviderForUI(k, func() *extensions.HeaderFooterConfig {
+		return k.Extensions().GetHeader()
+	})
 }
 
 // toolRendererProviderForUI returns a function that converts extension tool
@@ -493,11 +478,11 @@ func headerProviderForUI(k *kit.Kit) func() *ui.WidgetData {
 // disabled, which is safe — the UI treats a nil GetToolRenderer as "no
 // custom renderers".
 func toolRendererProviderForUI(k *kit.Kit) func(string) *ui.ToolRendererData {
-	if !k.HasExtensions() {
+	if !k.Extensions().HasExtensions() {
 		return nil
 	}
 	return func(toolName string) *ui.ToolRendererData {
-		config := k.GetExtensionToolRenderer(toolName)
+		config := k.Extensions().GetToolRenderer(toolName)
 		if config == nil {
 			return nil
 		}
@@ -517,11 +502,11 @@ func toolRendererProviderForUI(k *kit.Kit) func(string) *ui.ToolRendererData {
 // Returns nil if extensions are disabled, which is safe — the UI treats a
 // nil GetEditorInterceptor as "no interceptor".
 func editorInterceptorProviderForUI(k *kit.Kit) func() *ui.EditorInterceptor {
-	if !k.HasExtensions() {
+	if !k.Extensions().HasExtensions() {
 		return nil
 	}
 	return func() *ui.EditorInterceptor {
-		config := k.GetExtensionEditor()
+		config := k.Extensions().GetEditor()
 		if config == nil {
 			return nil
 		}
@@ -555,11 +540,11 @@ func editorInterceptorProviderForUI(k *kit.Kit) func() *ui.EditorInterceptor {
 // visibility overrides to a *ui.UIVisibility for the TUI. Returns nil if
 // extensions are disabled — the UI treats nil as "show everything".
 func uiVisibilityProviderForUI(k *kit.Kit) func() *ui.UIVisibility {
-	if !k.HasExtensions() {
+	if !k.Extensions().HasExtensions() {
 		return nil
 	}
 	return func() *ui.UIVisibility {
-		v := k.GetExtensionUIVisibility()
+		v := k.Extensions().GetUIVisibility()
 		if v == nil {
 			return nil
 		}
@@ -576,21 +561,9 @@ func uiVisibilityProviderForUI(k *kit.Kit) func() *ui.UIVisibility {
 // to a *ui.WidgetData for the TUI. Returns nil if extensions are disabled,
 // which is safe — the UI treats a nil GetFooter as "no footer".
 func footerProviderForUI(k *kit.Kit) func() *ui.WidgetData {
-	if !k.HasExtensions() {
-		return nil
-	}
-	return func() *ui.WidgetData {
-		config := k.GetExtensionFooter()
-		if config == nil {
-			return nil
-		}
-		return &ui.WidgetData{
-			Text:        config.Content.Text,
-			Markdown:    config.Content.Markdown,
-			BorderColor: config.Style.BorderColor,
-			NoBorder:    config.Style.NoBorder,
-		}
-	}
+	return headerFooterProviderForUI(k, func() *extensions.HeaderFooterConfig {
+		return k.Extensions().GetFooter()
+	})
 }
 
 // statusBarProviderForUI returns a function that fetches extension status bar
@@ -598,11 +571,11 @@ func footerProviderForUI(k *kit.Kit) func() *ui.WidgetData {
 // if extensions are disabled, which is safe — the TUI treats a nil
 // GetStatusBarEntries as "no extension entries".
 func statusBarProviderForUI(k *kit.Kit) func() []ui.StatusBarEntryData {
-	if !k.HasExtensions() {
+	if !k.Extensions().HasExtensions() {
 		return nil
 	}
 	return func() []ui.StatusBarEntryData {
-		entries := k.GetExtensionStatusEntries()
+		entries := k.Extensions().GetStatusEntries()
 		if len(entries) == 0 {
 			return nil
 		}
@@ -622,30 +595,36 @@ func statusBarProviderForUI(k *kit.Kit) func() []ui.StatusBarEntryData {
 // and returns (cancelled, reason). Returns nil if extensions are disabled —
 // the UI treats nil as "no hook".
 func beforeForkProviderForUI(k *kit.Kit) func(string, bool, string) (bool, string) {
-	if !k.HasExtensions() {
+	if !k.Extensions().HasExtensions() {
 		return nil
 	}
-	return k.EmitBeforeFork
+	return func(targetID string, isUserMsg bool, userText string) (bool, string) {
+		return k.Extensions().EmitBeforeFork(targetID, isUserMsg, userText)
+	}
 }
 
 // beforeSessionSwitchProviderForUI returns a callback that emits a
 // BeforeSessionSwitch event and returns (cancelled, reason). Returns nil
 // if extensions are disabled — the UI treats nil as "no hook".
 func beforeSessionSwitchProviderForUI(k *kit.Kit) func(string) (bool, string) {
-	if !k.HasExtensions() {
+	if !k.Extensions().HasExtensions() {
 		return nil
 	}
-	return k.EmitBeforeSessionSwitch
+	return func(switchReason string) (bool, string) {
+		return k.Extensions().EmitBeforeSessionSwitch(switchReason)
+	}
 }
 
 // globalShortcutsProviderForUI returns a callback that queries the extension
 // runner for registered keyboard shortcuts. Returns nil if extensions are
 // disabled — the UI treats nil as "no shortcuts".
 func globalShortcutsProviderForUI(k *kit.Kit) func() map[string]func() {
-	if !k.HasExtensions() {
+	if !k.Extensions().HasExtensions() {
 		return nil
 	}
-	return k.GetExtensionShortcuts
+	return func() map[string]func() {
+		return k.Extensions().GetShortcuts()
+	}
 }
 
 func runNormalMode(ctx context.Context) error {
@@ -677,9 +656,15 @@ func runNormalMode(ctx context.Context) error {
 	// Restore persisted model preference when no explicit --model flag or
 	// config file model is set. Precedence: CLI flag > config file > saved
 	// preference > built-in default. This mirrors how themes are persisted.
+	// Skip custom/* models unless --provider-url is also provided, since the
+	// custom provider requires a URL that was only valid for the previous session.
 	if !modelFlagChanged && !viper.InConfig("model") {
 		if pref := ui.LoadModelPreference(); pref != "" {
-			viper.Set("model", pref)
+			if strings.HasPrefix(pref, "custom/") && viper.GetString("provider-url") == "" {
+				// Don't restore custom models without a provider URL
+			} else {
+				viper.Set("model", pref)
+			}
 		}
 	}
 
@@ -700,6 +685,15 @@ func runNormalMode(ctx context.Context) error {
 		viper.Set("model", "custom/custom")
 	}
 
+	// When --provider-url is set with an explicit --model that lacks a provider
+	// prefix (no "/"), auto-prefix with "custom/" for OpenAI-compatible endpoints.
+	if viper.GetString("provider-url") != "" && modelFlagChanged {
+		model := viper.GetString("model")
+		if model != "" && !strings.Contains(model, "/") {
+			viper.Set("model", "custom/"+model)
+		}
+	}
+
 	// Load MCP configuration.
 	mcpConfig, err := config.LoadAndValidateConfig()
 	if err != nil {
@@ -710,7 +704,7 @@ func runNormalMode(ctx context.Context) error {
 	var spinnerFunc kit.SpinnerFunc
 	if !quietFlag {
 		spinnerFunc = func(fn func() error) error {
-			tempCli, tempErr := ui.NewCLI(viper.GetBool("debug"), viper.GetBool("compact"))
+			tempCli, tempErr := ui.NewCLI(viper.GetBool("debug"))
 			if tempErr == nil {
 				return tempCli.ShowSpinner(fn)
 			}
@@ -774,9 +768,9 @@ func runNormalMode(ctx context.Context) error {
 
 	// Load existing messages from resumed/continued sessions.
 	treeSession := kitInstance.GetTreeSession()
-	var messages []fantasy.Message
+	var messages []kit.LLMMessage
 	if treeSession != nil {
-		messages = treeSession.GetFantasyMessages()
+		messages = treeSession.GetLLMMessages()
 	}
 
 	// Create the app.App instance.
@@ -803,9 +797,9 @@ func runNormalMode(ctx context.Context) error {
 	var startupExtensionMessages []string
 
 	// Set up extension context and emit SessionStart.
-	if kitInstance.HasExtensions() {
+	if kitInstance.Extensions().HasExtensions() {
 		cwd, _ := os.Getwd()
-		kitInstance.SetExtensionContext(extensions.Context{
+		kitInstance.Extensions().SetContext(extensions.Context{
 			CWD:         cwd,
 			Model:       modelName,
 			Interactive: positionalPrompt == "",
@@ -824,28 +818,28 @@ func runNormalMode(ctx context.Context) error {
 			CancelAndSend: func(text string) { appInstance.InterruptAndSend(text) },
 			Exit:          func() { appInstance.QuitFromExtension() },
 			SetWidget: func(config extensions.WidgetConfig) {
-				kitInstance.SetExtensionWidget(config)
-				appInstance.NotifyWidgetUpdate()
+				kitInstance.Extensions().SetWidget(config)
+				go appInstance.NotifyWidgetUpdate()
 			},
 			RemoveWidget: func(id string) {
-				kitInstance.RemoveExtensionWidget(id)
-				appInstance.NotifyWidgetUpdate()
+				kitInstance.Extensions().RemoveWidget(id)
+				go appInstance.NotifyWidgetUpdate()
 			},
 			SetHeader: func(config extensions.HeaderFooterConfig) {
-				kitInstance.SetExtensionHeader(config)
-				appInstance.NotifyWidgetUpdate()
+				kitInstance.Extensions().SetHeader(config)
+				go appInstance.NotifyWidgetUpdate()
 			},
 			RemoveHeader: func() {
-				kitInstance.RemoveExtensionHeader()
-				appInstance.NotifyWidgetUpdate()
+				kitInstance.Extensions().RemoveHeader()
+				go appInstance.NotifyWidgetUpdate()
 			},
 			SetFooter: func(config extensions.HeaderFooterConfig) {
-				kitInstance.SetExtensionFooter(config)
-				appInstance.NotifyWidgetUpdate()
+				kitInstance.Extensions().SetFooter(config)
+				go appInstance.NotifyWidgetUpdate()
 			},
 			RemoveFooter: func() {
-				kitInstance.RemoveExtensionFooter()
-				appInstance.NotifyWidgetUpdate()
+				kitInstance.Extensions().RemoveFooter()
+				go appInstance.NotifyWidgetUpdate()
 			},
 			PromptSelect: func(config extensions.PromptSelectConfig) extensions.PromptSelectResult {
 				ch := make(chan app.PromptResponse, 1)
@@ -895,8 +889,8 @@ func runNormalMode(ctx context.Context) error {
 				return extensions.PromptInputResult{Value: resp.Value}
 			},
 			SetUIVisibility: func(v extensions.UIVisibility) {
-				kitInstance.SetExtensionUIVisibility(v)
-				appInstance.NotifyWidgetUpdate()
+				kitInstance.Extensions().SetUIVisibility(v)
+				go appInstance.NotifyWidgetUpdate()
 			},
 			GetContextStats: func() extensions.ContextStats {
 				s := kitInstance.GetContextStats()
@@ -908,53 +902,52 @@ func runNormalMode(ctx context.Context) error {
 				}
 			},
 			SetEditor: func(config extensions.EditorConfig) {
-				kitInstance.SetExtensionEditor(config)
-				// Use a goroutine for NotifyWidgetUpdate because this may be
-				// called from within an editor HandleKey callback, which runs
-				// synchronously inside BubbleTea's Update(). Calling prog.Send()
-				// directly from Update() deadlocks the event loop.
+				kitInstance.Extensions().SetEditor(config)
+				// 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.
 				go appInstance.NotifyWidgetUpdate()
 			},
 			ResetEditor: func() {
-				kitInstance.ResetExtensionEditor()
+				kitInstance.Extensions().ResetEditor()
 				go appInstance.NotifyWidgetUpdate()
 			},
 			GetMessages: func() []extensions.SessionMessage {
-				return kitInstance.GetSessionMessages()
+				return kitInstance.Extensions().GetSessionMessages()
 			},
 			GetSessionPath: func() string {
-				return kitInstance.GetSessionFilePath()
+				return kitInstance.GetSessionPath()
 			},
 			AppendEntry: func(entryType string, data string) (string, error) {
-				return kitInstance.AppendExtensionEntry(entryType, data)
+				return kitInstance.Extensions().AppendEntry(entryType, data)
 			},
 			GetEntries: func(entryType string) []extensions.ExtensionEntry {
-				return kitInstance.GetExtensionEntries(entryType)
+				return kitInstance.Extensions().GetEntries(entryType)
 			},
 			SetEditorText: func(text string) {
 				appInstance.SetEditorTextFromExtension(text)
 			},
 			SetStatus: func(key string, text string, priority int) {
-				kitInstance.SetExtensionStatus(extensions.StatusBarEntry{
+				kitInstance.Extensions().SetStatus(extensions.StatusBarEntry{
 					Key:      key,
 					Text:     text,
 					Priority: priority,
 				})
-				appInstance.NotifyWidgetUpdate()
+				go appInstance.NotifyWidgetUpdate()
 			},
 			RemoveStatus: func(key string) {
-				kitInstance.RemoveExtensionStatus(key)
-				appInstance.NotifyWidgetUpdate()
+				kitInstance.Extensions().RemoveStatus(key)
+				go appInstance.NotifyWidgetUpdate()
 			},
 			GetOption: func(name string) string {
-				return kitInstance.GetExtensionOption(name)
+				return kitInstance.Extensions().GetOption(name)
 			},
 			SetOption: func(name string, value string) {
-				kitInstance.SetExtensionOption(name, value)
+				kitInstance.Extensions().SetOption(name, value)
 			},
 			SetModel: func(modelString string) error {
 				// Capture previous model for the ModelChange event.
-				previousModel := kitInstance.GetExtensionContext().Model
+				previousModel := kitInstance.Extensions().GetContext().Model
 				err := kitInstance.SetModel(context.Background(), modelString)
 				if err != nil {
 					return err
@@ -963,9 +956,9 @@ func runNormalMode(ctx context.Context) error {
 				p, m, _ := models.ParseModelString(modelString)
 				appInstance.NotifyModelChanged(p, m)
 				// Update the context's Model field so handlers see it.
-				kitInstance.UpdateExtensionContextModel(modelString)
+				kitInstance.Extensions().UpdateContextModel(modelString)
 				// Fire OnModelChange event to extensions.
-				kitInstance.EmitModelChange(modelString, previousModel, "extension")
+				kitInstance.Extensions().EmitModelChange(modelString, previousModel, "extension")
 				// Update usage tracker with new model info for correct token counting.
 				if usageTracker != nil {
 					newProvider, newModel, _ := models.ParseModelString(modelString)
@@ -990,7 +983,7 @@ func runNormalMode(ctx context.Context) error {
 				return kitInstance.GetAvailableModels()
 			},
 			EmitCustomEvent: func(name string, data string) {
-				kitInstance.EmitExtensionCustomEvent(name, data)
+				kitInstance.Extensions().EmitCustomEvent(name, data)
 			},
 			Complete: func(req extensions.CompleteRequest) (extensions.CompleteResponse, error) {
 				return kitInstance.ExecuteCompletion(context.Background(), req)
@@ -999,7 +992,7 @@ func runNormalMode(ctx context.Context) error {
 				return appInstance.SuspendTUI(callback)
 			},
 			RenderMessage: func(rendererName, content string) {
-				renderer := kitInstance.GetExtensionMessageRenderer(rendererName)
+				renderer := kitInstance.Extensions().GetMessageRenderer(rendererName)
 				if renderer == nil || renderer.Render == nil {
 					appInstance.PrintFromExtension("", content)
 					return
@@ -1012,19 +1005,19 @@ func runNormalMode(ctx context.Context) error {
 				appInstance.PrintFromExtension("", rendered)
 			},
 			ReloadExtensions: func() error {
-				err := kitInstance.ReloadExtensions()
+				err := kitInstance.Extensions().Reload()
 				if err != nil {
 					return err
 				}
 				// Notify TUI that widgets/status/commands may have changed.
-				appInstance.NotifyWidgetUpdate()
+				go appInstance.NotifyWidgetUpdate()
 				return nil
 			},
 			GetAllTools: func() []extensions.ToolInfo {
-				return kitInstance.GetExtensionToolInfos()
+				return kitInstance.Extensions().GetToolInfos()
 			},
 			SetActiveTools: func(names []string) {
-				kitInstance.SetExtensionActiveTools(names)
+				kitInstance.Extensions().SetActiveTools(names)
 			},
 			RegisterTheme: func(name string, config extensions.ThemeColorConfig) {
 				tc := func(c extensions.ThemeColor) [2]string { return [2]string{c.Light, c.Dark} }
@@ -1095,7 +1088,7 @@ func runNormalMode(ctx context.Context) error {
 				}
 				extResult := &extensions.SubagentResult{
 					Response:  result.Response,
-					Error:     result.Error,
+					Error:     err,
 					SessionID: result.SessionID,
 					Elapsed:   result.Elapsed,
 				}
@@ -1149,16 +1142,19 @@ func runNormalMode(ctx context.Context) error {
 			GetChildren: kitInstance.GetChildren,
 			NavigateTo: func(entryID string) extensions.TreeNavigationResult {
 				err := kitInstance.NavigateTo(entryID)
-				if err != "" {
-					return extensions.TreeNavigationResult{Success: false, Error: err}
+				if err != nil {
+					return extensions.TreeNavigationResult{Success: false, Error: err.Error()}
 				}
 				return extensions.TreeNavigationResult{Success: true}
 			},
-			SummarizeBranch: kitInstance.SummarizeBranch,
+			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 != "" {
-					return extensions.TreeNavigationResult{Success: false, Error: err}
+				if err != nil {
+					return extensions.TreeNavigationResult{Success: false, Error: err.Error()}
 				}
 				return extensions.TreeNavigationResult{Success: true}
 			},
@@ -1207,10 +1203,10 @@ func runNormalMode(ctx context.Context) error {
 			ParseArguments:       kit.ParseArguments,
 			SimpleParseArguments: kit.SimpleParseArguments,
 			EvaluateModelConditional: func(condition string) bool {
-				return kit.EvaluateModelConditional(kitInstance.GetExtensionContext().Model, condition)
+				return kit.EvaluateModelConditional(kitInstance.Extensions().GetContext().Model, condition)
 			},
 			RenderWithModelConditionals: func(content string) string {
-				return kit.RenderWithModelConditionals(content, kitInstance.GetExtensionContext().Model)
+				return kit.RenderWithModelConditionals(content, kitInstance.Extensions().GetContext().Model)
 			},
 
 			// -------------------------------------------------------------------------
@@ -1222,16 +1218,16 @@ func runNormalMode(ctx context.Context) error {
 			},
 			CheckModelAvailable: kit.CheckModelAvailable,
 			GetCurrentProvider: func() string {
-				return kit.GetCurrentProvider(kitInstance.GetExtensionContext().Model)
+				return kit.GetCurrentProvider(kitInstance.Extensions().GetContext().Model)
 			},
 			GetCurrentModelID: func() string {
-				return kit.GetCurrentModelID(kitInstance.GetExtensionContext().Model)
+				return kit.GetCurrentModelID(kitInstance.Extensions().GetContext().Model)
 			},
 		})
-		kitInstance.EmitSessionStart()
+		kitInstance.Extensions().EmitSessionStart()
 
 		// Restore normal print functions for runtime use.
-		kitInstance.SetExtensionContext(extensions.Context{
+		kitInstance.Extensions().SetContext(extensions.Context{
 			CWD:           cwd,
 			Model:         modelName,
 			Interactive:   positionalPrompt == "",
@@ -1243,28 +1239,28 @@ func runNormalMode(ctx context.Context) error {
 			CancelAndSend: func(text string) { appInstance.InterruptAndSend(text) },
 			Exit:          func() { appInstance.QuitFromExtension() },
 			SetWidget: func(config extensions.WidgetConfig) {
-				kitInstance.SetExtensionWidget(config)
-				appInstance.NotifyWidgetUpdate()
+				kitInstance.Extensions().SetWidget(config)
+				go appInstance.NotifyWidgetUpdate()
 			},
 			RemoveWidget: func(id string) {
-				kitInstance.RemoveExtensionWidget(id)
-				appInstance.NotifyWidgetUpdate()
+				kitInstance.Extensions().RemoveWidget(id)
+				go appInstance.NotifyWidgetUpdate()
 			},
 			SetHeader: func(config extensions.HeaderFooterConfig) {
-				kitInstance.SetExtensionHeader(config)
-				appInstance.NotifyWidgetUpdate()
+				kitInstance.Extensions().SetHeader(config)
+				go appInstance.NotifyWidgetUpdate()
 			},
 			RemoveHeader: func() {
-				kitInstance.RemoveExtensionHeader()
-				appInstance.NotifyWidgetUpdate()
+				kitInstance.Extensions().RemoveHeader()
+				go appInstance.NotifyWidgetUpdate()
 			},
 			SetFooter: func(config extensions.HeaderFooterConfig) {
-				kitInstance.SetExtensionFooter(config)
-				appInstance.NotifyWidgetUpdate()
+				kitInstance.Extensions().SetFooter(config)
+				go appInstance.NotifyWidgetUpdate()
 			},
 			RemoveFooter: func() {
-				kitInstance.RemoveExtensionFooter()
-				appInstance.NotifyWidgetUpdate()
+				kitInstance.Extensions().RemoveFooter()
+				go appInstance.NotifyWidgetUpdate()
 			},
 			PromptSelect: func(config extensions.PromptSelectConfig) extensions.PromptSelectResult {
 				ch := make(chan app.PromptResponse, 1)
@@ -1360,7 +1356,7 @@ func runNormalMode(ctx context.Context) error {
 				}
 				extResult := &extensions.SubagentResult{
 					Response:  result.Response,
-					Error:     result.Error,
+					Error:     err,
 					SessionID: result.SessionID,
 					Elapsed:   result.Elapsed,
 				}
@@ -1414,16 +1410,19 @@ func runNormalMode(ctx context.Context) error {
 			GetChildren: kitInstance.GetChildren,
 			NavigateTo: func(entryID string) extensions.TreeNavigationResult {
 				err := kitInstance.NavigateTo(entryID)
-				if err != "" {
-					return extensions.TreeNavigationResult{Success: false, Error: err}
+				if err != nil {
+					return extensions.TreeNavigationResult{Success: false, Error: err.Error()}
 				}
 				return extensions.TreeNavigationResult{Success: true}
 			},
-			SummarizeBranch: kitInstance.SummarizeBranch,
+			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 != "" {
-					return extensions.TreeNavigationResult{Success: false, Error: err}
+				if err != nil {
+					return extensions.TreeNavigationResult{Success: false, Error: err.Error()}
 				}
 				return extensions.TreeNavigationResult{Success: true}
 			},
@@ -1472,10 +1471,10 @@ func runNormalMode(ctx context.Context) error {
 			ParseArguments:       kit.ParseArguments,
 			SimpleParseArguments: kit.SimpleParseArguments,
 			EvaluateModelConditional: func(condition string) bool {
-				return kit.EvaluateModelConditional(kitInstance.GetExtensionContext().Model, condition)
+				return kit.EvaluateModelConditional(kitInstance.Extensions().GetContext().Model, condition)
 			},
 			RenderWithModelConditionals: func(content string) string {
-				return kit.RenderWithModelConditionals(content, kitInstance.GetExtensionContext().Model)
+				return kit.RenderWithModelConditionals(content, kitInstance.Extensions().GetContext().Model)
 			},
 
 			// -------------------------------------------------------------------------
@@ -1487,10 +1486,10 @@ func runNormalMode(ctx context.Context) error {
 			},
 			CheckModelAvailable: kit.CheckModelAvailable,
 			GetCurrentProvider: func() string {
-				return kit.GetCurrentProvider(kitInstance.GetExtensionContext().Model)
+				return kit.GetCurrentProvider(kitInstance.Extensions().GetContext().Model)
 			},
 			GetCurrentModelID: func() string {
-				return kit.GetCurrentModelID(kitInstance.GetExtensionContext().Model)
+				return kit.GetCurrentModelID(kitInstance.Extensions().GetContext().Model)
 			},
 		})
 	}
@@ -1549,7 +1548,7 @@ func runNormalMode(ctx context.Context) error {
 	emitBeforeFork := beforeForkProviderForUI(kitInstance)
 	emitBeforeSessionSwitch := beforeSessionSwitchProviderForUI(kitInstance)
 	getGlobalShortcuts := globalShortcutsProviderForUI(kitInstance)
-	getExtensionCommands := func() []ui.ExtensionCommand {
+	getExtensionCommands := func() []commands.ExtensionCommand {
 		return extensionCommandsForUI(kitInstance)
 	}
 
@@ -1560,7 +1559,7 @@ func runNormalMode(ctx context.Context) error {
 			return err
 		}
 		// Update the extension context's Model field so handlers see it.
-		kitInstance.UpdateExtensionContextModel(modelString)
+		kitInstance.Extensions().UpdateContextModel(modelString)
 		// NOTE: We do NOT call appInstance.NotifyModelChanged() here because
 		// this callback runs synchronously inside BubbleTea's Update(), and
 		// NotifyModelChanged calls prog.Send() which deadlocks. The UI layer
@@ -1586,7 +1585,7 @@ func runNormalMode(ctx context.Context) error {
 		return nil
 	}
 	emitModelChangeForUI := func(newModel, previousModel, source string) {
-		kitInstance.EmitModelChange(newModel, previousModel, source)
+		kitInstance.Extensions().EmitModelChange(newModel, previousModel, source)
 	}
 
 	// Build thinking level callback.
@@ -1606,9 +1605,36 @@ func runNormalMode(ctx context.Context) error {
 		return nil
 	}
 
+	// Build extension reload callback for the /reload-ext command.
+	reloadExtensionsForUI := func() error {
+		err := kitInstance.Extensions().Reload()
+		if err != nil {
+			return err
+		}
+		go appInstance.NotifyWidgetUpdate()
+		return nil
+	}
+
+	// Start file watcher for automatic extension hot-reload.
+	extraPaths := viper.GetStringSlice("extension")
+	watchDirs := extensions.WatchedDirs(extraPaths)
+	if len(watchDirs) > 0 {
+		extWatcher, watchErr := extensions.NewWatcher(watchDirs, func() {
+			if err := reloadExtensionsForUI(); err != nil {
+				log.Printf("auto-reload extensions failed: %v", err)
+			}
+		})
+		if watchErr != nil {
+			log.Printf("extension file watcher not started: %v", watchErr)
+		} else {
+			go extWatcher.Start(ctx)
+			defer func() { _ = extWatcher.Close() }()
+		}
+	}
+
 	// Check if running in non-interactive mode
 	if positionalPrompt != "" {
-		return runNonInteractiveModeApp(ctx, appInstance, cli, positionalPrompt, quietFlag, jsonFlag, noExitFlag, modelName, parsedProvider, kitInstance.GetLoadingMessage(), serverNames, toolNames, mcpToolCount, extensionToolCount, usageTracker, extCommands, promptTemplates, contextPaths, skillItems, getWidgets, getHeader, getFooter, getToolRenderer, getEditorInterceptor, getUIVisibility, getStatusBarEntries, emitBeforeFork, emitBeforeSessionSwitch, getGlobalShortcuts, getExtensionCommands, setModelForUI, emitModelChangeForUI, kitInstance.IsReasoningModel(), kitInstance.GetThinkingLevel(), setThinkingLevelForUI, switchSessionForUI)
+		return runNonInteractiveModeApp(ctx, appInstance, cli, positionalPrompt, quietFlag, jsonFlag, noExitFlag, modelName, parsedProvider, kitInstance.GetLoadingMessage(), serverNames, toolNames, mcpToolCount, extensionToolCount, usageTracker, extCommands, promptTemplates, contextPaths, skillItems, getWidgets, getHeader, getFooter, getToolRenderer, getEditorInterceptor, getUIVisibility, getStatusBarEntries, emitBeforeFork, emitBeforeSessionSwitch, getGlobalShortcuts, getExtensionCommands, setModelForUI, emitModelChangeForUI, kitInstance.IsReasoningModel(), kitInstance.GetThinkingLevel(), setThinkingLevelForUI, switchSessionForUI, reloadExtensionsForUI)
 	}
 
 	// Quiet mode is not allowed in interactive mode
@@ -1616,7 +1642,7 @@ func runNormalMode(ctx context.Context) error {
 		return fmt.Errorf("--quiet requires a prompt")
 	}
 
-	return runInteractiveModeBubbleTea(ctx, appInstance, modelName, parsedProvider, kitInstance.GetLoadingMessage(), serverNames, toolNames, mcpToolCount, extensionToolCount, usageTracker, extCommands, promptTemplates, contextPaths, skillItems, getWidgets, getHeader, getFooter, getToolRenderer, getEditorInterceptor, getUIVisibility, getStatusBarEntries, emitBeforeFork, emitBeforeSessionSwitch, getGlobalShortcuts, getExtensionCommands, setModelForUI, emitModelChangeForUI, kitInstance.IsReasoningModel(), kitInstance.GetThinkingLevel(), setThinkingLevelForUI, switchSessionForUI, startupExtensionMessages)
+	return runInteractiveModeBubbleTea(ctx, appInstance, modelName, parsedProvider, kitInstance.GetLoadingMessage(), serverNames, toolNames, mcpToolCount, extensionToolCount, usageTracker, extCommands, promptTemplates, contextPaths, skillItems, getWidgets, getHeader, getFooter, getToolRenderer, getEditorInterceptor, getUIVisibility, getStatusBarEntries, emitBeforeFork, emitBeforeSessionSwitch, getGlobalShortcuts, getExtensionCommands, setModelForUI, emitModelChangeForUI, kitInstance.IsReasoningModel(), kitInstance.GetThinkingLevel(), setThinkingLevelForUI, switchSessionForUI, reloadExtensionsForUI, startupExtensionMessages)
 }
 
 // runNonInteractiveModeApp executes a single prompt via the app layer and exits,
@@ -1629,7 +1655,7 @@ func runNormalMode(ctx context.Context) error {
 //
 // When --no-exit is set, after the prompt completes the interactive BubbleTea
 // TUI is started so the user can continue the conversation.
-func runNonInteractiveModeApp(ctx context.Context, appInstance *app.App, cli *ui.CLI, prompt string, quiet, jsonOutput, noExit bool, modelName, providerName, loadingMessage string, serverNames, toolNames []string, mcpToolCount, extensionToolCount int, usageTracker *ui.UsageTracker, extCommands []ui.ExtensionCommand, promptTemplates []*prompts.PromptTemplate, contextPaths []string, skillItems []ui.SkillItem, getWidgets func(string) []ui.WidgetData, getHeader, getFooter func() *ui.WidgetData, getToolRenderer func(string) *ui.ToolRendererData, getEditorInterceptor func() *ui.EditorInterceptor, getUIVisibility func() *ui.UIVisibility, getStatusBarEntries func() []ui.StatusBarEntryData, emitBeforeFork func(string, bool, string) (bool, string), emitBeforeSessionSwitch func(string) (bool, string), getGlobalShortcuts func() map[string]func(), getExtensionCommands func() []ui.ExtensionCommand, setModel func(string) error, emitModelChange func(string, string, string), isReasoningModel bool, thinkingLevel string, setThinkingLevel func(string) error, switchSession func(string) error) error {
+func runNonInteractiveModeApp(ctx context.Context, appInstance *app.App, cli *ui.CLI, prompt string, quiet, jsonOutput, noExit bool, modelName, providerName, loadingMessage string, serverNames, toolNames []string, mcpToolCount, extensionToolCount int, usageTracker *ui.UsageTracker, extCommands []commands.ExtensionCommand, promptTemplates []*prompts.PromptTemplate, contextPaths []string, skillItems []ui.SkillItem, getWidgets func(string) []ui.WidgetData, getHeader, getFooter func() *ui.WidgetData, getToolRenderer func(string) *ui.ToolRendererData, getEditorInterceptor func() *ui.EditorInterceptor, getUIVisibility func() *ui.UIVisibility, getStatusBarEntries func() []ui.StatusBarEntryData, emitBeforeFork func(string, bool, string) (bool, string), emitBeforeSessionSwitch func(string) (bool, string), getGlobalShortcuts func() map[string]func(), getExtensionCommands func() []commands.ExtensionCommand, setModel func(string) error, emitModelChange func(string, string, string), isReasoningModel bool, thinkingLevel string, setThinkingLevel func(string) error, switchSession func(string) error, reloadExtensions func() error) error {
 	// Expand @file references in the prompt before sending to the agent.
 	if cwd, err := os.Getwd(); err == nil {
 		prompt = ui.ProcessFileAttachments(prompt, cwd)
@@ -1672,7 +1698,7 @@ func runNonInteractiveModeApp(ctx context.Context, appInstance *app.App, cli *ui
 
 	// If --no-exit was requested, hand off to the interactive TUI.
 	if noExit {
-		return runInteractiveModeBubbleTea(ctx, appInstance, modelName, providerName, loadingMessage, serverNames, toolNames, mcpToolCount, extensionToolCount, usageTracker, extCommands, promptTemplates, contextPaths, skillItems, getWidgets, getHeader, getFooter, getToolRenderer, getEditorInterceptor, getUIVisibility, getStatusBarEntries, emitBeforeFork, emitBeforeSessionSwitch, getGlobalShortcuts, getExtensionCommands, setModel, emitModelChange, isReasoningModel, thinkingLevel, setThinkingLevel, switchSession, nil)
+		return runInteractiveModeBubbleTea(ctx, appInstance, modelName, providerName, loadingMessage, serverNames, toolNames, mcpToolCount, extensionToolCount, usageTracker, extCommands, promptTemplates, contextPaths, skillItems, getWidgets, getHeader, getFooter, getToolRenderer, getEditorInterceptor, getUIVisibility, getStatusBarEntries, emitBeforeFork, emitBeforeSessionSwitch, getGlobalShortcuts, getExtensionCommands, setModel, emitModelChange, isReasoningModel, thinkingLevel, setThinkingLevel, switchSession, reloadExtensions, nil)
 	}
 
 	return nil
@@ -1727,7 +1753,7 @@ func buildJSONOutput(result *kit.TurnResult, model string) ([]byte, error) {
 	}
 
 	for _, fmsg := range result.Messages {
-		converted := kit.ConvertFromFantasyMessage(fmsg)
+		converted := kit.ConvertFromLLMMessage(fmsg)
 		m := jsonMessage{Role: string(converted.Role)}
 		for _, p := range converted.Parts {
 			switch c := p.(type) {
@@ -1770,7 +1796,7 @@ func writeJSONError(err error) {
 //  4. Calls program.Run() which blocks until the user quits (Ctrl+C or /quit).
 //
 // SetupCLI is not used for interactive mode; the TUI (AppModel) handles its own rendering.
-func runInteractiveModeBubbleTea(_ context.Context, appInstance *app.App, modelName, providerName, loadingMessage string, serverNames, toolNames []string, mcpToolCount, extensionToolCount int, usageTracker *ui.UsageTracker, extCommands []ui.ExtensionCommand, promptTemplates []*prompts.PromptTemplate, contextPaths []string, skillItems []ui.SkillItem, getWidgets func(string) []ui.WidgetData, getHeader, getFooter func() *ui.WidgetData, getToolRenderer func(string) *ui.ToolRendererData, getEditorInterceptor func() *ui.EditorInterceptor, getUIVisibility func() *ui.UIVisibility, getStatusBarEntries func() []ui.StatusBarEntryData, emitBeforeFork func(string, bool, string) (bool, string), emitBeforeSessionSwitch func(string) (bool, string), getGlobalShortcuts func() map[string]func(), getExtensionCommands func() []ui.ExtensionCommand, setModel func(string) error, emitModelChange func(string, string, string), isReasoningModel bool, thinkingLevel string, setThinkingLevel func(string) error, switchSession func(string) error, startupExtensionMessages []string) error {
+func runInteractiveModeBubbleTea(_ context.Context, appInstance *app.App, modelName, providerName, loadingMessage string, serverNames, toolNames []string, mcpToolCount, extensionToolCount int, usageTracker *ui.UsageTracker, extCommands []commands.ExtensionCommand, promptTemplates []*prompts.PromptTemplate, contextPaths []string, skillItems []ui.SkillItem, getWidgets func(string) []ui.WidgetData, getHeader, getFooter func() *ui.WidgetData, getToolRenderer func(string) *ui.ToolRendererData, getEditorInterceptor func() *ui.EditorInterceptor, getUIVisibility func() *ui.UIVisibility, getStatusBarEntries func() []ui.StatusBarEntryData, emitBeforeFork func(string, bool, string) (bool, string), emitBeforeSessionSwitch func(string) (bool, string), getGlobalShortcuts func() map[string]func(), getExtensionCommands func() []commands.ExtensionCommand, setModel func(string) error, emitModelChange func(string, string, string), isReasoningModel bool, thinkingLevel string, setThinkingLevel func(string) error, switchSession func(string) error, reloadExtensions func() error, startupExtensionMessages []string) error {
 	// Determine terminal size; fall back gracefully.
 	termWidth, termHeight, err := term.GetSize(int(os.Stdout.Fd()))
 	if err != nil || termWidth == 0 {
@@ -1781,54 +1807,43 @@ func runInteractiveModeBubbleTea(_ context.Context, appInstance *app.App, modelN
 	cwd, _ := os.Getwd()
 
 	appModel := ui.NewAppModel(appInstance, ui.AppModelOptions{
-		CompactMode:             viper.GetBool("compact"),
-		ModelName:               modelName,
-		ProviderName:            providerName,
-		LoadingMessage:          loadingMessage,
-		Cwd:                     cwd,
-		Width:                   termWidth,
-		Height:                  termHeight,
-		ServerNames:             serverNames,
-		ToolNames:               toolNames,
-		MCPToolCount:            mcpToolCount,
-		ExtensionToolCount:      extensionToolCount,
-		UsageTracker:            usageTracker,
-		ExtensionCommands:       extCommands,
-		PromptTemplates:         promptTemplates,
-		ContextPaths:            contextPaths,
-		SkillItems:              skillItems,
-		GetWidgets:              getWidgets,
-		GetHeader:               getHeader,
-		GetFooter:               getFooter,
-		GetToolRenderer:         getToolRenderer,
-		GetEditorInterceptor:    getEditorInterceptor,
-		GetUIVisibility:         getUIVisibility,
-		GetStatusBarEntries:     getStatusBarEntries,
-		EmitBeforeFork:          emitBeforeFork,
-		EmitBeforeSessionSwitch: emitBeforeSessionSwitch,
-		GetGlobalShortcuts:      getGlobalShortcuts,
-		GetExtensionCommands:    getExtensionCommands,
-		SetModel:                setModel,
-		EmitModelChange:         emitModelChange,
-		ThinkingLevel:           thinkingLevel,
-		IsReasoningModel:        isReasoningModel,
-		SetThinkingLevel:        setThinkingLevel,
-		SwitchSession:           switchSession,
-		ShowSessionPicker:       resumeFlag,
+		ModelName:                modelName,
+		ProviderName:             providerName,
+		LoadingMessage:           loadingMessage,
+		Cwd:                      cwd,
+		Width:                    termWidth,
+		Height:                   termHeight,
+		ServerNames:              serverNames,
+		ToolNames:                toolNames,
+		MCPToolCount:             mcpToolCount,
+		ExtensionToolCount:       extensionToolCount,
+		UsageTracker:             usageTracker,
+		ExtensionCommands:        extCommands,
+		PromptTemplates:          promptTemplates,
+		ContextPaths:             contextPaths,
+		SkillItems:               skillItems,
+		StartupExtensionMessages: startupExtensionMessages,
+		GetWidgets:               getWidgets,
+		GetHeader:                getHeader,
+		GetFooter:                getFooter,
+		GetToolRenderer:          getToolRenderer,
+		GetEditorInterceptor:     getEditorInterceptor,
+		GetUIVisibility:          getUIVisibility,
+		GetStatusBarEntries:      getStatusBarEntries,
+		EmitBeforeFork:           emitBeforeFork,
+		EmitBeforeSessionSwitch:  emitBeforeSessionSwitch,
+		GetGlobalShortcuts:       getGlobalShortcuts,
+		GetExtensionCommands:     getExtensionCommands,
+		SetModel:                 setModel,
+		EmitModelChange:          emitModelChange,
+		ThinkingLevel:            thinkingLevel,
+		IsReasoningModel:         isReasoningModel,
+		SetThinkingLevel:         setThinkingLevel,
+		SwitchSession:            switchSession,
+		ReloadExtensions:         reloadExtensions,
+		ShowSessionPicker:        resumeFlag,
 	})
 
-	// Print startup info to stdout before Bubble Tea takes over the screen.
-	appModel.PrintStartupInfo()
-
-	// Print any extension messages that were captured during startup.
-	if len(startupExtensionMessages) > 0 {
-		fmt.Println()
-		for _, msg := range startupExtensionMessages {
-			fmt.Println(msg)
-		}
-		fmt.Println()
-	}
-
 	program := tea.NewProgram(appModel)
 
 	// Register the program with the app layer so agent events are sent to the TUI.

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/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/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/kit-telegram/main.go

@@ -908,7 +908,7 @@ 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

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/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) {

go.mod

@@ -3,16 +3,20 @@ module github.com/mark3labs/kit
 go 1.26.1
 
 require (
-	charm.land/bubbles/v2 v2.0.0
+	charm.land/bubbles/v2 v2.1.0
 	charm.land/bubbletea/v2 v2.0.2
 	charm.land/fantasy v0.17.1
 	charm.land/huh/v2 v2.0.3
 	charm.land/lipgloss/v2 v2.0.2
 	github.com/alecthomas/chroma/v2 v2.23.1
+	github.com/atotto/clipboard v0.1.4
 	github.com/aymanbagabas/go-udiff v0.4.1
 	github.com/charmbracelet/fang v1.0.0
 	github.com/charmbracelet/log v1.0.0
+	github.com/charmbracelet/openai-go v0.0.0-20260319145158-d0740cc34266
 	github.com/coder/acp-go-sdk v0.6.3
+	github.com/indaco/herald v0.11.0
+	github.com/indaco/herald-md v0.2.0
 	github.com/mark3labs/mcp-go v0.46.0
 	github.com/spf13/cobra v1.10.2
 	github.com/spf13/viper v1.21.0
@@ -28,35 +32,32 @@ require (
 	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 v1.41.5 // indirect
 	github.com/aws/aws-sdk-go-v2/aws/protocol/eventstream v1.7.8 // 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/config v1.32.13 // indirect
+	github.com/aws/aws-sdk-go-v2/credentials v1.19.13 // indirect
+	github.com/aws/aws-sdk-go-v2/feature/ec2/imds v1.18.21 // indirect
+	github.com/aws/aws-sdk-go-v2/internal/configsources v1.4.21 // indirect
+	github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.7.21 // 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/aws-sdk-go-v2/service/internal/presigned-url v1.13.21 // indirect
+	github.com/aws/aws-sdk-go-v2/service/signin v1.0.9 // indirect
+	github.com/aws/aws-sdk-go-v2/service/sso v1.30.14 // indirect
+	github.com/aws/aws-sdk-go-v2/service/ssooidc v1.35.18 // indirect
+	github.com/aws/aws-sdk-go-v2/service/sts v1.41.10 // indirect
 	github.com/aws/smithy-go v1.24.2 // indirect
-	github.com/aymerick/douceur v0.2.0 // 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/ultraviolet v0.0.0-20260330092749-0f94982c930b // indirect
 	github.com/charmbracelet/x/cellbuf v0.0.15 // indirect
-	github.com/charmbracelet/x/exp/charmtone v0.0.0-20260323091123-df7b1bcffcca // indirect
+	github.com/charmbracelet/x/exp/charmtone v0.0.0-20260330094520-2dce04b6f8a4 // indirect
 	github.com/charmbracelet/x/exp/ordered v0.1.0 // indirect
-	github.com/charmbracelet/x/exp/slice v0.0.0-20260323091123-df7b1bcffcca // indirect
+	github.com/charmbracelet/x/exp/slice v0.0.0-20260330094520-2dce04b6f8a4 // 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
@@ -80,19 +81,15 @@ require (
 	github.com/google/uuid v1.6.0 // indirect
 	github.com/googleapis/enterprise-certificate-proxy v0.3.14 // indirect
 	github.com/googleapis/gax-go/v2 v2.20.0 // indirect
-	github.com/gorilla/css v1.0.1 // indirect
 	github.com/gorilla/websocket v1.5.3 // indirect
-	github.com/indaco/herald v0.9.0 // indirect
-	github.com/kaptinlin/go-i18n v0.2.12 // indirect
+	github.com/kaptinlin/go-i18n v0.3.0 // 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/microcosm-cc/bluemonday v1.0.27 // indirect
+	github.com/kaptinlin/jsonschema v0.7.7 // indirect
+	github.com/kaptinlin/messageformat-go v0.4.19 // 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 v2.3.0 // indirect
 	github.com/sagikazarmark/locafero v0.12.0 // indirect
@@ -106,7 +103,6 @@ require (
 	github.com/xo/terminfo v0.0.0-20220910002029-abceb7e1c41e // indirect
 	github.com/yosida95/uritemplate/v3 v3.0.2 // indirect
 	github.com/yuin/goldmark v1.8.2 // indirect
-	github.com/yuin/goldmark-emoji v1.0.6 // 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
@@ -119,21 +115,20 @@ require (
 	golang.org/x/net v0.52.0 // indirect
 	golang.org/x/oauth2 v0.36.0 // indirect
 	golang.org/x/time v0.15.0 // indirect
-	google.golang.org/api v0.273.0 // 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 v0.273.1 // indirect
+	google.golang.org/genai v1.52.1 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20260401024825-9d38bb4040a9 // indirect
+	google.golang.org/grpc v1.80.0 // 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/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/lucasb-eyer/go-colorful v1.4.0 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/mattn/go-runewidth v0.0.21 // indirect
 	github.com/muesli/cancelreader v0.2.2 // indirect

go.sum

@@ -1,5 +1,5 @@
-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/bubbles/v2 v2.1.0 h1:YSnNh5cPYlYjPxRrzs5VEn3vwhtEn3jVGRBT3M7/I0g=
+charm.land/bubbles/v2 v2.1.0/go.mod h1:l97h4hym2hvWBVfmJDtrEHHCtkIKeTEb3TTJ4ZOB3wY=
 charm.land/bubbletea/v2 v2.0.2 h1:4CRtRnuZOdFDTWSff9r8QFt/9+z6Emubz3aDMnf/dx0=
 charm.land/bubbletea/v2 v2.0.2/go.mod h1:3LRff2U4WIYXy7MTxfbAQ+AdfM3D8Xuvz2wbsOD9OHQ=
 charm.land/fantasy v0.17.1 h1:SQzfnyJPDuQWt6e//KKmQmEEXdqHMC0IZz10XwkLcEM=
@@ -34,42 +34,40 @@ 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/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 v1.41.5 h1:dj5kopbwUsVUVFgO4Fi5BIT3t4WyqIDjGKCangnV/yY=
+github.com/aws/aws-sdk-go-v2 v1.41.5/go.mod h1:mwsPRE8ceUUpiTgF7QmQIJ7lgsKUPQOUl3o72QBrE1o=
 github.com/aws/aws-sdk-go-v2/aws/protocol/eventstream v1.7.8 h1:eBMB84YGghSocM7PsjmmPffTa+1FBUeNvGvFou6V/4o=
 github.com/aws/aws-sdk-go-v2/aws/protocol/eventstream v1.7.8/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/config v1.32.13 h1:5KgbxMaS2coSWRrx9TX/QtWbqzgQkOdEa3sZPhBhCSg=
+github.com/aws/aws-sdk-go-v2/config v1.32.13/go.mod h1:8zz7wedqtCbw5e9Mi2doEwDyEgHcEE9YOJp6a8jdSMY=
+github.com/aws/aws-sdk-go-v2/credentials v1.19.13 h1:mA59E3fokBvyEGHKFdnpNNrvaR351cqiHgRg+JzOSRI=
+github.com/aws/aws-sdk-go-v2/credentials v1.19.13/go.mod h1:yoTXOQKea18nrM69wGF9jBdG4WocSZA1h38A+t/MAsk=
+github.com/aws/aws-sdk-go-v2/feature/ec2/imds v1.18.21 h1:NUS3K4BTDArQqNu2ih7yeDLaS3bmHD0YndtA6UP884g=
+github.com/aws/aws-sdk-go-v2/feature/ec2/imds v1.18.21/go.mod h1:YWNWJQNjKigKY1RHVJCuupeWDrrHjRqHm0N9rdrWzYI=
+github.com/aws/aws-sdk-go-v2/internal/configsources v1.4.21 h1:Rgg6wvjjtX8bNHcvi9OnXWwcE0a2vGpbwmtICOsvcf4=
+github.com/aws/aws-sdk-go-v2/internal/configsources v1.4.21/go.mod h1:A/kJFst/nm//cyqonihbdpQZwiUhhzpqTsdbhDdRF9c=
+github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.7.21 h1:PEgGVtPoB6NTpPrBgqSE5hE/o47Ij9qk/SEZFbUOe9A=
+github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.7.21/go.mod h1:p+hz+PRAYlY3zcpJhPwXlLC4C+kqn70WIHwnzAfs6ps=
 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/aws-sdk-go-v2/service/internal/presigned-url v1.13.21 h1:c31//R3xgIJMSC8S6hEVq+38DcvUlgFY0FM6mSI5oto=
+github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.13.21/go.mod h1:r6+pf23ouCB718FUxaqzZdbpYFyDtehyZcmP5KL9FkA=
+github.com/aws/aws-sdk-go-v2/service/signin v1.0.9 h1:QKZH0S178gCmFEgst8hN0mCX1KxLgHBKKY/CLqwP8lg=
+github.com/aws/aws-sdk-go-v2/service/signin v1.0.9/go.mod h1:7yuQJoT+OoH8aqIxw9vwF+8KpvLZ8AWmvmUWHsGQZvI=
+github.com/aws/aws-sdk-go-v2/service/sso v1.30.14 h1:GcLE9ba5ehAQma6wlopUesYg/hbcOhFNWTjELkiWkh4=
+github.com/aws/aws-sdk-go-v2/service/sso v1.30.14/go.mod h1:WSvS1NLr7JaPunCXqpJnWk1Bjo7IxzZXrZi1QQCkuqM=
+github.com/aws/aws-sdk-go-v2/service/ssooidc v1.35.18 h1:mP49nTpfKtpXLt5SLn8Uv8z6W+03jYVoOSAl/c02nog=
+github.com/aws/aws-sdk-go-v2/service/ssooidc v1.35.18/go.mod h1:YO8TrYtFdl5w/4vmjL8zaBSsiNp3w0L1FfKVKenZT7w=
+github.com/aws/aws-sdk-go-v2/service/sts v1.41.10 h1:p8ogvvLugcR/zLBXTXrTkj0RYBUdErbMnAFFp12Lm/U=
+github.com/aws/aws-sdk-go-v2/service/sts v1.41.10/go.mod h1:60dv0eZJfeVXfbT1tFJinbHrDfSJ2GZl4Q//OSSNAVw=
 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/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/catppuccin/go v0.3.0 h1:d+0/YicIq+hSTo5oPuRi5kOpqkVA5tAsU6dNhvRu+aY=
 github.com/catppuccin/go v0.3.0/go.mod h1:8IHJuMGaUUjQM82qBrGNBv7LFq6JI3NnQCF6MOlZjpc=
 github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
@@ -80,8 +78,6 @@ 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=
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@@ -100,14 +96,14 @@ github.com/charmbracelet/x/conpty v0.1.1 h1:s1bUxjoi7EpqiXysVtC+a8RrvPPNcNvAjfi4
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@@ -179,41 +175,38 @@ github.com/googleapis/enterprise-certificate-proxy v0.3.14 h1:yh8ncqsbUY4shRD5dA
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@@ -224,8 +217,6 @@ github.com/muesli/mango-cobra v1.3.0 h1:vQy5GvPg3ndOSpduxutqFoINhWk3vD5K2dXo5E8p
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@@ -238,8 +229,6 @@ github.com/planetscale/vtprotobuf v0.6.1-0.20240319094008-0393e58bdf10 h1:GFCKgm
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@@ -281,8 +270,6 @@ github.com/yosida95/uritemplate/v3 v3.0.2 h1:Ed3Oyj9yrmi9087+NczuL5BwkIc4wvTb5zI
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@@ -320,20 +307,20 @@ golang.org/x/text v0.35.0 h1:JOVx6vVDFokkpaq1AEptVzLTpDe9KGpj5tR4/X+ybL8=
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 google.golang.org/genproto v0.0.0-20260319201613-d00831a3d3e7/go.mod h1:L43LFes82YgSonw6iTXTxXUX1OlULt4AQtkik4ULL/I=
 google.golang.org/genproto/googleapis/api v0.0.0-20260319201613-d00831a3d3e7 h1:41r6JMbpzBMen0R/4TZeeAmGXSJC7DftGINUodzTkPI=
 google.golang.org/genproto/googleapis/api v0.0.0-20260319201613-d00831a3d3e7/go.mod h1:EIQZ5bFCfRQDV4MhRle7+OgjNtZ6P1PiZBgAKuxXu/Y=
-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=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20260401024825-9d38bb4040a9 h1:m8qni9SQFH0tJc1X0vmnpw/0t+AImlSvp30sEupozUg=
+google.golang.org/genproto/googleapis/rpc v0.0.0-20260401024825-9d38bb4040a9/go.mod h1:4Hqkh8ycfw05ld/3BWL7rJOSfebL2Q+DVDeRgYgxUU8=
+google.golang.org/grpc v1.80.0 h1:Xr6m2WmWZLETvUNvIUmeD5OAagMw3FiKmMlTdViWsHM=
+google.golang.org/grpc v1.80.0/go.mod h1:ho/dLnxwi3EDJA4Zghp7k2Ec1+c2jqup0bFkw07bwF4=
 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=

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"
@@ -20,6 +23,17 @@ import (
 // Version is injected at build time; fallback to "dev".
 var Version = "dev"
 
+// thinkingTagOpen and thinkingTagClose are the XML-style tags that some models
+// (Qwen, DeepSeek) wrap reasoning content in. We parse these to extract
+// reasoning/thinking content and send it as ACP thought updates.
+// Also support <think> format used by some models.
+const (
+	thinkingTagOpen    = "<thinking>"
+	thinkingTagClose   = "</thinking>"
+	shortThinkTagOpen  = "<think>"
+	shortThinkTagClose = "</think>"
+)
+
 // Agent implements the acp.Agent interface, delegating to Kit for LLM
 // execution, tool calls, and session management.
 type Agent struct {
@@ -28,6 +42,10 @@ type Agent struct {
 
 	// toolCallCounter provides unique IDs for tool calls within a turn.
 	toolCallCounter atomic.Int64
+
+	// inThinkingTag tracks whether we're currently inside a <thinking> tag
+	// when parsing streaming content from models that wrap reasoning in XML tags.
+	inThinkingTag bool
 }
 
 // NewAgent creates a new ACP agent backed by Kit.
@@ -111,13 +129,23 @@ 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))
+
+	// Reset thinking tag state for this new prompt turn
+	a.inThinkingTag = false
 
 	// Create a cancellable context for this prompt turn.
 	promptCtx, cancel := context.WithCancel(ctx)
@@ -129,7 +157,13 @@ 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 +196,24 @@ func (a *Agent) SetSessionMode(_ context.Context, _ acp.SetSessionModeRequest) (
 	return acp.SetSessionModeResponse{}, nil
 }
 
+// SetSessionModel changes the active model for a session.
+func (a *Agent) SetSessionModel(ctx context.Context, params acp.SetSessionModelRequest) (acp.SetSessionModelResponse, error) {
+	sessionID := string(params.SessionId)
+	sess, ok := a.registry.get(sessionID)
+	if !ok {
+		return acp.SetSessionModelResponse{}, acp.NewInvalidParams(fmt.Sprintf("session not found: %s", sessionID))
+	}
+
+	modelID := string(params.ModelId)
+	log.Debug("acp: set_session_model", "session", sessionID, "model", modelID)
+
+	if err := sess.kit.SetModel(ctx, modelID); err != nil {
+		return acp.SetSessionModelResponse{}, fmt.Errorf("set model: %w", err)
+	}
+
+	return acp.SetSessionModelResponse{}, nil
+}
+
 // ---------------------------------------------------------------------------
 // Event streaming: Kit events → ACP SessionUpdate notifications
 // ---------------------------------------------------------------------------
@@ -178,8 +230,24 @@ func (a *Agent) subscribeEvents(ctx context.Context, k *kit.Kit, sessionID acp.S
 		var update *acp.SessionUpdate
 		switch ev := e.(type) {
 		case kit.MessageUpdateEvent:
-			u := acp.UpdateAgentMessageText(ev.Chunk)
-			update = &u
+			// Handle models that wrap reasoning in <thinking> tags (Qwen, DeepSeek)
+			// Parse the chunk and separate reasoning from regular text
+			reasoning, text := a.parseThinkingTags(ev.Chunk)
+
+			// Send reasoning update if we have reasoning content
+			if reasoning != "" {
+				u := acp.UpdateAgentThoughtText(reasoning)
+				_ = a.conn.SessionUpdate(ctx, acp.SessionNotification{
+					SessionId: sessionID,
+					Update:    u,
+				})
+			}
+
+			// Send text update if we have text content
+			if text != "" {
+				u := acp.UpdateAgentMessageText(text)
+				update = &u
+			}
 
 		case kit.ReasoningDeltaEvent:
 			u := acp.UpdateAgentThoughtText(ev.Delta)
@@ -231,19 +299,271 @@ 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
+}
+
+// parseThinkingTags parses a text chunk for <thinking> or  tags and separates
+// reasoning content from regular text. This handles models (Qwen, DeepSeek)
+// that wrap reasoning in XML-style tags instead of using proper reasoning events.
+// Returns (reasoningContent, textContent).
+func (a *Agent) parseThinkingTags(chunk string) (reasoning string, text string) {
+	// Handle empty chunk
+	if chunk == "" {
+		return "", ""
+	}
+
+	// Determine which tag format to use (long or short)
+	openTag := thinkingTagOpen
+	closeTag := thinkingTagClose
+
+	if strings.Contains(chunk, shortThinkTagOpen) || strings.Contains(chunk, shortThinkTagClose) {
+		openTag = shortThinkTagOpen
+		closeTag = shortThinkTagClose
+	} else if !strings.Contains(chunk, thinkingTagOpen) && !strings.Contains(chunk, thinkingTagClose) && !a.inThinkingTag {
+		// No tags at all and not in thinking mode - return as text
+		return "", chunk
+	}
+
+	// Check for opening tag
+	if strings.Contains(chunk, openTag) {
+		parts := strings.SplitN(chunk, openTag, 2)
+
+		// Content before the opening tag is regular text
+		if !a.inThinkingTag && parts[0] != "" {
+			text = parts[0]
+		}
+
+		a.inThinkingTag = true
+
+		// Content after the opening tag is reasoning
+		if len(parts) > 1 {
+			// Check if the same chunk contains the closing tag
+			if strings.Contains(parts[1], closeTag) {
+				innerParts := strings.SplitN(parts[1], closeTag, 2)
+				reasoning = innerParts[0]
+				a.inThinkingTag = false
+
+				// Content after closing tag is regular text
+				if len(innerParts) > 1 && innerParts[1] != "" {
+					text += innerParts[1]
+				}
+			} else if parts[1] != "" {
+				// No closing tag yet, all remaining content is reasoning
+				reasoning = parts[1]
+			}
+		}
+		return reasoning, text
+	}
+
+	// Check for closing tag
+	if strings.Contains(chunk, closeTag) {
+		parts := strings.SplitN(chunk, closeTag, 2)
+		a.inThinkingTag = false
+
+		// Content before closing tag is reasoning
+		reasoning = parts[0]
+
+		// Content after closing tag is regular text
+		if len(parts) > 1 && parts[1] != "" {
+			text = parts[1]
+		}
+		return reasoning, text
+	}
+
+	// No tags found - content goes to current mode
+	if a.inThinkingTag {
+		return chunk, ""
+	}
+	return "", chunk
+}
+
+// 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

@@ -62,8 +62,8 @@ func (r *sessionRegistry) create(ctx context.Context, cwd string) (*acpSession,
 	// 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{
+	if kitInstance.Extensions().HasExtensions() {
+		kitInstance.Extensions().SetContext(extensions.Context{
 			SessionID:   sessionID,
 			CWD:         cwd,
 			Model:       kitInstance.GetModelString(),
@@ -121,31 +121,31 @@ func (r *sessionRegistry) create(ctx context.Context, cwd string) (*acpSession,
 					MessageCount:    s.MessageCount,
 				}
 			},
-			GetMessages:    func() []extensions.SessionMessage { return kitInstance.GetSessionMessages() },
-			GetSessionPath: func() string { return kitInstance.GetSessionFilePath() },
+			GetMessages:    func() []extensions.SessionMessage { return kitInstance.Extensions().GetSessionMessages() },
+			GetSessionPath: func() string { return kitInstance.GetSessionPath() },
 			AppendEntry: func(entryType, data string) (string, error) {
-				return kitInstance.AppendExtensionEntry(entryType, data)
+				return kitInstance.Extensions().AppendEntry(entryType, data)
 			},
 			GetEntries: func(entryType string) []extensions.ExtensionEntry {
-				return kitInstance.GetExtensionEntries(entryType)
+				return kitInstance.Extensions().GetEntries(entryType)
 			},
 
 			// Options, model, and tool management.
-			GetOption: func(name string) string { return kitInstance.GetExtensionOption(name) },
-			SetOption: func(name, value string) { kitInstance.SetExtensionOption(name, value) },
+			GetOption: func(name string) string { return kitInstance.Extensions().GetOption(name) },
+			SetOption: func(name, value string) { kitInstance.Extensions().SetOption(name, value) },
 			SetModel: func(modelString string) error {
-				previousModel := kitInstance.GetExtensionContext().Model
+				previousModel := kitInstance.Extensions().GetContext().Model
 				if err := kitInstance.SetModel(context.Background(), modelString); err != nil {
 					return err
 				}
-				kitInstance.UpdateExtensionContextModel(modelString)
-				kitInstance.EmitModelChange(modelString, previousModel, "extension")
+				kitInstance.Extensions().UpdateContextModel(modelString)
+				kitInstance.Extensions().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) },
+			EmitCustomEvent:    func(name, data string) { kitInstance.Extensions().EmitCustomEvent(name, data) },
+			GetAllTools:        func() []extensions.ToolInfo { return kitInstance.Extensions().GetToolInfos() },
+			SetActiveTools:     func(names []string) { kitInstance.Extensions().SetActiveTools(names) },
 
 			// LLM completions and subagents.
 			Complete: func(req extensions.CompleteRequest) (extensions.CompleteResponse, error) {
@@ -173,7 +173,7 @@ func (r *sessionRegistry) create(ctx context.Context, cwd string) (*acpSession,
 				}
 				extResult := &extensions.SubagentResult{
 					Response:  result.Response,
-					Error:     result.Error,
+					Error:     err,
 					SessionID: result.SessionID,
 					Elapsed:   result.Elapsed,
 				}
@@ -188,15 +188,15 @@ func (r *sessionRegistry) create(ctx context.Context, cwd string) (*acpSession,
 
 			// Render — fall back to logging.
 			RenderMessage: func(name, content string) {
-				renderer := kitInstance.GetExtensionMessageRenderer(name)
+				renderer := kitInstance.Extensions().GetMessageRenderer(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() },
+			ReloadExtensions: func() error { return kitInstance.Extensions().Reload() },
 		})
-		kitInstance.EmitSessionStart()
+		kitInstance.Extensions().EmitSessionStart()
 	}
 
 	sess := &acpSession{

internal/agent/agent.go

@@ -31,7 +31,7 @@ type AgentConfig struct {
 	CoreTools []fantasy.AgentTool
 
 	// ToolWrapper is an optional function that wraps the combined tool list
-	// before it is passed to the Fantasy agent. Used by the extensions system
+	// before it is passed to the LLM agent. Used by the extensions system
 	// to intercept tool calls/results.
 	ToolWrapper func([]fantasy.AgentTool) []fantasy.AgentTool
 
@@ -63,6 +63,10 @@ type ToolCallContentHandler func(content string)
 // ReasoningDeltaHandler is a function type for handling streaming reasoning/thinking deltas.
 type ReasoningDeltaHandler func(delta string)
 
+// ReasoningCompleteHandler is a function type for handling reasoning/thinking completion.
+// Called when the last reasoning token has been processed, before text streaming starts.
+type ReasoningCompleteHandler func()
+
 // ToolOutputHandler is a function type for handling streaming tool output chunks.
 // Used by tools like bash to stream output as it arrives rather than waiting
 // for the command to complete. The isStderr flag indicates if the chunk
@@ -75,9 +79,9 @@ type ToolOutputHandler = core.ToolOutputCallback
 // tracking during long-running tool-calling conversations.
 type StepUsageHandler func(inputTokens, outputTokens, cacheReadTokens, cacheCreationTokens int64)
 
-// Agent represents an AI agent with core tool integration using the fantasy library.
+// Agent represents an AI agent with core tool integration using the LLM library.
 // Core tools (bash, read, write, edit, grep, find, ls) are registered as direct
-// fantasy.AgentTool implementations — no MCP layer, no serialization overhead.
+// AgentTool implementations — no MCP layer, no serialization overhead.
 // Additional tools from external MCP servers can be loaded alongside core tools.
 type Agent struct {
 	toolManager      *tools.MCPToolManager
@@ -100,7 +104,7 @@ type GenerateWithLoopResult struct {
 	FinalResponse *fantasy.Response
 	// ConversationMessages contains all messages in the conversation including tool calls and results
 	ConversationMessages []fantasy.Message
-	// Messages contains the conversation as custom content blocks (crush-style)
+	// Messages contains the conversation as custom content blocks
 	Messages []message.Message
 	// TotalUsage contains aggregate token usage across all steps
 	TotalUsage fantasy.Usage
@@ -112,13 +116,13 @@ type GenerateWithLoopResult struct {
 // Core tools (bash, read, write, edit, grep, find, ls) are always registered.
 // External MCP tools are loaded from the config if any MCP servers are configured.
 func NewAgent(ctx context.Context, agentConfig *AgentConfig) (*Agent, error) {
-	// Create the LLM provider via fantasy
+	// Create the LLM provider
 	providerResult, err := models.CreateProvider(ctx, agentConfig.ModelConfig)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create model provider: %v", err)
 	}
 
-	// Register core tools (direct fantasy implementations, no MCP overhead).
+	// Register core tools (direct AgentTool implementations, no MCP overhead).
 	// Use caller-provided tools if set, otherwise default to all core tools.
 	coreTools := agentConfig.CoreTools
 	if len(coreTools) == 0 {
@@ -158,7 +162,7 @@ func NewAgent(ctx context.Context, agentConfig *AgentConfig) (*Agent, error) {
 		allTools = agentConfig.ToolWrapper(allTools)
 	}
 
-	// Build fantasy agent options
+	// Build agent options
 	var agentOpts []fantasy.AgentOption
 
 	if agentConfig.SystemPrompt != "" {
@@ -198,7 +202,7 @@ func NewAgent(ctx context.Context, agentConfig *AgentConfig) (*Agent, error) {
 		}
 	}
 
-	// Create the fantasy agent
+	// Create the agent
 	fantasyAgent := fantasy.NewAgent(providerResult.Model, agentOpts...)
 
 	// Determine provider type from model string
@@ -231,17 +235,18 @@ func (a *Agent) GenerateWithLoop(ctx context.Context, messages []fantasy.Message
 	onResponse ResponseHandler, onToolCallContent ToolCallContentHandler,
 ) (*GenerateWithLoopResult, error) {
 	return a.GenerateWithLoopAndStreaming(ctx, messages, onToolCall, onToolExecution, onToolResult,
-		onResponse, onToolCallContent, nil, nil, nil, nil)
+		onResponse, onToolCallContent, nil, nil, nil, nil, nil)
 }
 
-// GenerateWithLoopAndStreaming processes messages using the fantasy agent with streaming and callbacks.
-// Fantasy handles the tool call loop internally. We map fantasy's rich callback system
+// GenerateWithLoopAndStreaming processes messages using the agent with streaming and callbacks.
+// The agent handles the tool call loop internally. We map the rich callback system
 // to kit's existing callback interface for UI integration.
 func (a *Agent) GenerateWithLoopAndStreaming(ctx context.Context, messages []fantasy.Message,
 	onToolCall ToolCallHandler, onToolExecution ToolExecutionHandler, onToolResult ToolResultHandler,
 	onResponse ResponseHandler, onToolCallContent ToolCallContentHandler,
 	onStreamingResponse StreamingResponseHandler,
 	onReasoningDelta ReasoningDeltaHandler,
+	onReasoningComplete ReasoningCompleteHandler,
 	onToolOutput ToolOutputHandler,
 	onStepUsage StepUsageHandler,
 ) (*GenerateWithLoopResult, error) {
@@ -251,18 +256,21 @@ func (a *Agent) GenerateWithLoopAndStreaming(ctx context.Context, messages []fan
 		ctx = core.ContextWithToolOutputCallback(ctx, onToolOutput)
 	}
 
-	// Fantasy requires the current user input as Prompt, with prior messages as history.
+	// The agent requires the current user input as Prompt, with prior messages as history.
 	// Extract the last user message text and files as the prompt, and pass everything
 	// before it as Messages. Files (e.g. clipboard images) are passed via the Files
-	// field so Fantasy includes them in the API request.
+	// field so the agent includes them in the API request.
 	prompt, files, history := splitPromptAndHistory(messages)
 
-	// Track current tool call info for callbacks
-	var currentToolName string
+	// Apply message-level cache control for Anthropic models.
+	// This avoids type conflicts with provider-level options.
+	history = applyCacheControlToMessages(history)
+
+	// Track current tool call args for callbacks
 	var currentToolArgs string
 
 	// Use the streaming path when streaming is enabled OR when any callbacks are
-	// provided. Fantasy only exposes tool/step callbacks on AgentStreamCall, so
+	// provided. The agent only exposes tool/step callbacks on AgentStreamCall, so
 	// Stream is required to observe tool execution in real time. The non-streaming
 	// Generate path is reserved for the simple case with no callbacks at all.
 	hasCallbacks := onToolCall != nil || onToolExecution != nil || onToolResult != nil ||
@@ -270,12 +278,12 @@ func (a *Agent) GenerateWithLoopAndStreaming(ctx context.Context, messages []fan
 
 	if a.streamingEnabled || hasCallbacks {
 		// Track completed step messages so we can return partial results
-		// on cancellation. Fantasy's Stream() discards accumulated steps
+		// on cancellation. The agent's Stream() discards accumulated steps
 		// when it returns an error, but the OnStepFinish callback fires
 		// for every step that completed before the error occurred.
 		var completedStepMessages []fantasy.Message
 
-		// Use fantasy's streaming agent
+		// Use the streaming agent
 		streamCall := fantasy.AgentStreamCall{
 			Prompt:   prompt,
 			Files:    files,
@@ -292,6 +300,17 @@ func (a *Agent) GenerateWithLoopAndStreaming(ctx context.Context, messages []fan
 				return nil
 			},
 
+			// Reasoning/thinking complete callback
+			OnReasoningEnd: func(id string, _ fantasy.ReasoningContent) error {
+				if ctx.Err() != nil {
+					return ctx.Err()
+				}
+				if onReasoningComplete != nil {
+					onReasoningComplete()
+				}
+				return nil
+			},
+
 			// Text streaming callback
 			OnTextDelta: func(id, text string) error {
 				if ctx.Err() != nil {
@@ -308,7 +327,6 @@ func (a *Agent) GenerateWithLoopAndStreaming(ctx context.Context, messages []fan
 				if ctx.Err() != nil {
 					return ctx.Err()
 				}
-				currentToolName = tc.ToolName
 				currentToolArgs = tc.Input
 
 				// Notify about the tool call
@@ -379,7 +397,7 @@ func (a *Agent) GenerateWithLoopAndStreaming(ctx context.Context, messages []fan
 				opts fantasy.PrepareStepFunctionOptions,
 			) (context.Context, fantasy.PrepareStepResult, error) {
 				// Drain all pending steer messages (non-blocking).
-				var steered []string
+				var steered []SteerMessage
 				for {
 					select {
 					case msg := <-steerCh:
@@ -396,15 +414,20 @@ func (a *Agent) GenerateWithLoopAndStreaming(ctx context.Context, messages []fan
 				if len(steered) > 0 {
 					// Inject each steer message as a user message so the
 					// LLM sees the redirection on the next step.
-					for _, text := range steered {
+					for _, sm := range steered {
 						result.Messages = append(result.Messages,
-							fantasy.NewUserMessage(text))
+							fantasy.NewUserMessage(sm.Text, sm.Files...))
 					}
 					// Notify that steer messages were consumed.
 					if onConsumed != nil {
 						onConsumed(len(steered))
 					}
 				}
+
+				// Apply message-level cache control for Anthropic models.
+				// This avoids type conflicts with provider-level options.
+				result.Messages = applyCacheControlToMessages(result.Messages)
+
 				return stepCtx, result, nil
 			}
 		}
@@ -452,13 +475,11 @@ func (a *Agent) GenerateWithLoopAndStreaming(ctx context.Context, messages []fan
 		onResponse(result.Response.Content.Text())
 	}
 
-	_ = currentToolName // satisfy compiler for non-streaming path
-
 	return convertAgentResult(result, messages), nil
 }
 
 // splitPromptAndHistory extracts the last user message as the prompt string,
-// and returns everything before it as conversation history. Fantasy's agent
+// and returns everything before it as conversation history. The agent's
 // requires the current turn's input as Prompt (string), with prior messages
 // passed separately as Messages (history).
 func splitPromptAndHistory(messages []fantasy.Message) (string, []fantasy.FilePart, []fantasy.Message) {
@@ -501,8 +522,8 @@ func splitPromptAndHistory(messages []fantasy.Message) (string, []fantasy.FilePa
 	return "", nil, messages
 }
 
-// convertAgentResult converts a fantasy AgentResult to our GenerateWithLoopResult.
-// It builds both the legacy fantasy.Message slice and the new custom content blocks.
+// convertAgentResult converts an AgentResult to our GenerateWithLoopResult.
+// It builds both the message slice and the new custom content blocks.
 func convertAgentResult(result *fantasy.AgentResult, originalMessages []fantasy.Message) *GenerateWithLoopResult {
 	// Collect all conversation messages: original + all step messages
 	var allFantasyMessages []fantasy.Message
@@ -515,7 +536,7 @@ func convertAgentResult(result *fantasy.AgentResult, originalMessages []fantasy.
 	// Convert to custom content blocks
 	var allMessages []message.Message
 	for _, fm := range allFantasyMessages {
-		allMessages = append(allMessages, message.FromFantasyMessage(fm))
+		allMessages = append(allMessages, message.FromLLMMessage(fm))
 	}
 
 	return &GenerateWithLoopResult{
@@ -527,7 +548,7 @@ func convertAgentResult(result *fantasy.AgentResult, originalMessages []fantasy.
 	}
 }
 
-// extractToolResultText extracts the text and error status from a fantasy ToolResultContent.
+// extractToolResultText extracts the text and error status from a ToolResultContent.
 // For core tools, the result is already clean text (no MCP JSON wrapping).
 // For MCP tools, it unwraps the MCP content structure.
 func extractToolResultText(tr fantasy.ToolResultContent) (string, bool) {
@@ -540,7 +561,7 @@ func extractToolResultText(tr fantasy.ToolResultContent) (string, bool) {
 		return errResult.Error.Error(), true
 	}
 
-	// Get text directly from the Fantasy result type.
+	// Get text directly from the result type.
 	if textResult, ok := tr.Result.(fantasy.ToolResultOutputContentText); ok {
 		// Try to unwrap MCP JSON structure (for external MCP tools).
 		// Core tools return plain text, so this is a no-op for them.
@@ -618,6 +639,43 @@ func (a *Agent) GetExtensionToolCount() int {
 	return len(a.extraTools)
 }
 
+// SetExtraTools replaces the agent's extra tools (e.g. extension-registered
+// tools) and rebuilds the internal agent with the updated tool list. The
+// model, system prompt, and all other configuration are preserved.
+func (a *Agent) SetExtraTools(tools []fantasy.AgentTool) {
+	a.extraTools = tools
+
+	// Rebuild tool list (same as NewAgent / SetModel).
+	allTools := make([]fantasy.AgentTool, len(a.coreTools))
+	copy(allTools, a.coreTools)
+	if a.toolManager != nil {
+		allTools = append(allTools, a.toolManager.GetTools()...)
+	}
+	if len(a.extraTools) > 0 {
+		allTools = append(allTools, a.extraTools...)
+	}
+	if a.toolWrapper != nil {
+		allTools = a.toolWrapper(allTools)
+	}
+
+	// Rebuild agent options with the existing model.
+	var agentOpts []fantasy.AgentOption
+	if a.systemPrompt != "" {
+		agentOpts = append(agentOpts, fantasy.WithSystemPrompt(a.systemPrompt))
+	}
+	if len(allTools) > 0 {
+		agentOpts = append(agentOpts, fantasy.WithTools(allTools...))
+	}
+	if a.maxSteps > 0 {
+		agentOpts = append(agentOpts, fantasy.WithStopConditions(
+			fantasy.StepCountIs(a.maxSteps),
+		))
+	}
+
+	// Swap the fantasy agent (model and provider are unchanged).
+	a.fantasyAgent = fantasy.NewAgent(a.model, agentOpts...)
+}
+
 // GetLoadingMessage returns the loading message from provider creation.
 func (a *Agent) GetLoadingMessage() string {
 	return a.loadingMessage
@@ -653,7 +711,7 @@ func (a *Agent) SetModel(ctx context.Context, config *models.ProviderConfig) err
 		allTools = a.toolWrapper(allTools)
 	}
 
-	// Rebuild fantasy agent options.
+	// Rebuild agent options.
 	var agentOpts []fantasy.AgentOption
 	if a.systemPrompt != "" {
 		agentOpts = append(agentOpts, fantasy.WithSystemPrompt(a.systemPrompt))
@@ -714,7 +772,7 @@ func (a *Agent) SetModel(ctx context.Context, config *models.ProviderConfig) err
 	return nil
 }
 
-// GetModel returns the underlying fantasy LanguageModel.
+// GetModel returns the underlying LanguageModel.
 func (a *Agent) GetModel() fantasy.LanguageModel {
 	return a.model
 }

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

@@ -39,7 +39,7 @@ type AgentCreationOptions struct {
 	// 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.
+	// 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

internal/agent/steer.go

@@ -1,6 +1,17 @@
 package agent
 
-import "context"
+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{}
@@ -11,7 +22,7 @@ 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 string) context.Context {
+func ContextWithSteerCh(ctx context.Context, ch <-chan SteerMessage) context.Context {
 	return context.WithValue(ctx, steerChKey{}, ch)
 }
 
@@ -23,8 +34,8 @@ func ContextWithSteerConsumed(ctx context.Context, fn func(count int)) context.C
 }
 
 // steerChFromContext extracts the steer channel from the context, or nil.
-func steerChFromContext(ctx context.Context) <-chan string {
-	ch, _ := ctx.Value(steerChKey{}).(<-chan string)
+func steerChFromContext(ctx context.Context) <-chan SteerMessage {
+	ch, _ := ctx.Value(steerChKey{}).(<-chan SteerMessage)
 	return ch
 }
 

internal/app/app.go

@@ -7,6 +7,7 @@ import (
 	"os"
 	"sync"
 	"sync/atomic"
+	"time"
 
 	tea "charm.land/bubbletea/v2"
 	"charm.land/fantasy"
@@ -19,7 +20,7 @@ import (
 // queueItem holds a prompt and optional image attachments for the execution queue.
 type queueItem struct {
 	Prompt string
-	Files  []fantasy.FilePart
+	Files  []kit.LLMFilePart
 }
 
 // App is the application-layer orchestrator. It owns the agentic loop,
@@ -68,11 +69,20 @@ type App struct {
 	// rootCtx/rootCancel are used to signal shutdown to all goroutines.
 	rootCtx    context.Context
 	rootCancel context.CancelFunc
+
+	// widgetUpdatePending is set to true when a WidgetUpdateEvent has been
+	// sent to the TUI but not yet consumed by its event loop. While the flag
+	// is set, subsequent NotifyWidgetUpdate calls are coalesced (dropped) to
+	// prevent fast extension tickers from flooding the BubbleTea mailbox with
+	// redundant re-render triggers. The flag is cleared after a short debounce
+	// (~1 frame) so new updates are always let through once the TUI has had a
+	// chance to process the pending event.
+	widgetUpdatePending atomic.Bool
 }
 
 // New creates a new App with the provided options and pre-loaded messages.
 // initialMessages may be nil or empty for a fresh session.
-func New(opts Options, initialMessages []fantasy.Message) *App {
+func New(opts Options, initialMessages []kit.LLMMessage) *App {
 	rootCtx, rootCancel := context.WithCancel(context.Background())
 	return &App{
 		opts:       opts,
@@ -116,9 +126,8 @@ func (a *App) Run(prompt string) int {
 // If the app is idle the prompt executes immediately; otherwise it is queued.
 // Returns the current queue depth (0 = started immediately, >0 = queued).
 //
-// Satisfies ui.AppController (via RunWithImages which converts ImageAttachment
-// to fantasy.FilePart).
-func (a *App) RunWithFiles(prompt string, files []fantasy.FilePart) int {
+// Satisfies ui.AppController.
+func (a *App) RunWithFiles(prompt string, files []kit.LLMFilePart) int {
 	a.mu.Lock()
 
 	if a.closed {
@@ -178,6 +187,15 @@ func (a *App) QueueLength() int {
 //
 // Satisfies ui.AppController.
 func (a *App) Steer(prompt string) int {
+	return a.SteerWithFiles(prompt, nil)
+}
+
+// SteerWithFiles injects a steering message with optional file attachments
+// (e.g. pasted images) into the currently running agent turn. Behaves like
+// Steer but includes file parts alongside the text.
+//
+// Satisfies ui.AppController.
+func (a *App) SteerWithFiles(prompt string, files []kit.LLMFilePart) int {
 	a.mu.Lock()
 
 	if a.closed {
@@ -186,8 +204,8 @@ func (a *App) Steer(prompt string) int {
 	}
 
 	if !a.busy {
-		// Not busy — start immediately, same as Run().
-		item := queueItem{Prompt: prompt}
+		// Not busy — start immediately, same as RunWithFiles().
+		item := queueItem{Prompt: prompt, Files: files}
 		a.busy = true
 		a.wg.Add(1)
 		a.mu.Unlock()
@@ -202,7 +220,7 @@ func (a *App) Steer(prompt string) int {
 	// execution, before next LLM call). If PrepareStep doesn't fire
 	// (text-only response), drainQueue will pick it up after the turn.
 	if a.opts.Kit != nil {
-		a.opts.Kit.InjectSteer(prompt)
+		a.opts.Kit.InjectSteerWithFiles(prompt, files)
 	}
 	return 1
 }
@@ -261,6 +279,17 @@ func (a *App) ClearMessages() {
 	}
 }
 
+// ReloadMessagesFromTree clears the in-memory message store and reloads it
+// from the tree session's current branch. Unlike ClearMessages, this does NOT
+// reset the tree session's leaf pointer. Used after Branch() to sync the
+// store with the new branch position.
+func (a *App) ReloadMessagesFromTree() {
+	a.store.Clear()
+	if a.opts.TreeSession != nil {
+		a.store.Replace(a.opts.TreeSession.GetLLMMessages())
+	}
+}
+
 // GetTreeSession returns the tree session manager, or nil if not configured.
 func (a *App) GetTreeSession() *session.TreeManager {
 	return a.opts.TreeSession
@@ -282,7 +311,7 @@ func (a *App) SwitchTreeSession(ts *session.TreeManager) {
 	// Reload messages from new session.
 	a.store.Clear()
 	if ts != nil {
-		a.store.Replace(ts.GetFantasyMessages())
+		a.store.Replace(ts.GetLLMMessages())
 	}
 }
 
@@ -293,12 +322,12 @@ func (a *App) SwitchTreeSession(ts *session.TreeManager) {
 //
 // Satisfies ui.AppController.
 func (a *App) AddContextMessage(text string) {
-	msg := fantasy.NewUserMessage(text)
-	a.store.Add(msg)
+	kitMsg := fantasy.NewUserMessage(text)
+	a.store.Add(kitMsg)
 
 	// Persist to tree session if active.
 	if ts := a.opts.TreeSession; ts != nil {
-		_, _ = ts.AppendFantasyMessage(msg)
+		_, _ = ts.AppendLLMMessage(fantasy.NewUserMessage(text))
 	}
 }
 
@@ -336,6 +365,15 @@ func (a *App) CompactConversation(customInstructions string) error {
 			a.mu.Unlock()
 		}()
 
+		// Subscribe to SDK events for streaming compaction summary to the TUI.
+		sendFn := func(msg tea.Msg) {
+			if a.program != nil {
+				a.program.Send(msg)
+			}
+		}
+		unsub := a.subscribeSDKEvents(sendFn, nil)
+		defer unsub()
+
 		result, err := a.opts.Kit.Compact(a.rootCtx, nil, customInstructions)
 		if err != nil {
 			a.sendEvent(CompactErrorEvent{Err: err})
@@ -348,7 +386,7 @@ func (a *App) CompactConversation(customInstructions string) error {
 
 		// Sync in-memory store with the compacted session.
 		if a.opts.TreeSession != nil {
-			a.store.Replace(a.opts.TreeSession.GetFantasyMessages())
+			a.store.Replace(a.opts.TreeSession.GetLLMMessages())
 		}
 
 		a.sendEvent(CompactCompleteEvent{
@@ -485,11 +523,10 @@ func (a *App) drainQueue(first queueItem) {
 		a.mu.Lock()
 		items = append(items, a.queue...)
 		a.queue = a.queue[:0] // Clear the queue
-		queueLen := len(a.queue)
 		a.mu.Unlock()
 
-		// Send queue updated event (queue is now empty)
-		a.sendEvent(QueueUpdatedEvent{Length: queueLen})
+		// Notify UI: all queued messages have been consumed into this batch.
+		a.sendEvent(QueueUpdatedEvent{Length: 0})
 
 		// Process all collected items as a single batch
 		a.runQueueBatch(items)
@@ -502,8 +539,8 @@ func (a *App) drainQueue(first queueItem) {
 			if leftover := a.opts.Kit.DrainSteer(); len(leftover) > 0 {
 				a.mu.Lock()
 				steerItems := make([]queueItem, len(leftover))
-				for i, text := range leftover {
-					steerItems[i] = queueItem{Prompt: text}
+				for i, sm := range leftover {
+					steerItems[i] = queueItem{Prompt: sm.Text, Files: sm.Files}
 				}
 				a.queue = append(steerItems, a.queue...)
 				a.mu.Unlock()
@@ -522,6 +559,11 @@ func (a *App) drainQueue(first queueItem) {
 		}
 		a.mu.Unlock()
 
+		if hasMore {
+			// Notify UI: these newly queued messages have been consumed into the next batch.
+			a.sendEvent(QueueUpdatedEvent{Length: 0})
+		}
+
 		if !hasMore {
 			// No more items, we're done
 			break
@@ -569,7 +611,7 @@ func (a *App) runQueueBatch(items []queueItem) {
 			// call/result pairs; only the in-progress message or tool
 			// call is discarded. Sync the in-memory store to match.
 			if ts := a.opts.TreeSession; ts != nil {
-				a.store.Replace(ts.GetFantasyMessages())
+				a.store.Replace(ts.GetLLMMessages())
 			}
 			a.sendEvent(StepCancelledEvent{})
 			return
@@ -588,7 +630,7 @@ func (a *App) runQueueBatch(items []queueItem) {
 // executeStep runs a single agentic step by delegating to the SDK's
 // PromptResult() (or PromptResultWithFiles for multimodal), which handles
 // session persistence, hooks, extension events, and the generation loop.
-func (a *App) executeStep(ctx context.Context, prompt string, eventFn func(tea.Msg), files []fantasy.FilePart) (*kit.TurnResult, error) {
+func (a *App) executeStep(ctx context.Context, prompt string, eventFn func(tea.Msg), files []kit.LLMFilePart) (*kit.TurnResult, error) {
 	// Test hook: bypass SDK entirely.
 	if a.opts.PromptFunc != nil {
 		return a.opts.PromptFunc(ctx, prompt)
@@ -685,8 +727,8 @@ func (a *App) executeBatch(ctx context.Context, items []queueItem, eventFn func(
 			messages = append(messages, item.Prompt)
 		}
 
-		// TODO: Handle file attachments in batch mode
-		// For now, files are ignored in batch mode (rare edge case)
+		// File attachments are not supported in batch mode; fall back to
+		// processing only the first item that carries files.
 		if hasFiles {
 			// If files exist, fall back to processing just the first item with files
 			for _, item := range items {
@@ -755,6 +797,8 @@ func (a *App) subscribeSDKEvents(sendFn func(tea.Msg), stepUsageSeen *atomic.Boo
 			sendFn(StreamChunkEvent{Content: ev.Chunk})
 		case kit.ReasoningDeltaEvent:
 			sendFn(ReasoningChunkEvent{Delta: ev.Delta})
+		case kit.ReasoningCompleteEvent:
+			sendFn(ReasoningCompleteEvent{})
 		case kit.ToolOutputEvent:
 			sendFn(ToolOutputEvent{
 				ToolCallID: ev.ToolCallID,
@@ -834,12 +878,32 @@ func (a *App) NotifyModelChanged(provider, model string) {
 // NotifyWidgetUpdate sends a WidgetUpdateEvent to the TUI so it re-renders
 // extension widgets. Called from the extension context's SetWidget/RemoveWidget
 // closures. In non-interactive mode this is a no-op (widgets are TUI-only).
+//
+// Coalescing: if a WidgetUpdateEvent is already queued and not yet consumed
+// by the TUI event loop, additional calls within the same ~16 ms window are
+// dropped. This prevents fast extension tickers from flooding BubbleTea's
+// mailbox with redundant re-render triggers.
 func (a *App) NotifyWidgetUpdate() {
+	// Coalesce: only one pending update at a time.
+	if !a.widgetUpdatePending.CompareAndSwap(false, true) {
+		return
+	}
 	a.mu.Lock()
 	prog := a.program
 	a.mu.Unlock()
 	if prog != nil {
 		prog.Send(WidgetUpdateEvent{})
+		// Reset the pending flag after a short debounce so subsequent calls
+		// within the same render cycle are also coalesced, but new updates
+		// after the cycle are allowed through.
+		go func() {
+			time.Sleep(16 * time.Millisecond) // ~1 frame at 60 fps
+			a.widgetUpdatePending.Store(false)
+		}()
+	} else {
+		// No program registered (non-interactive mode); clear the flag so
+		// future calls are never permanently blocked.
+		a.widgetUpdatePending.Store(false)
 	}
 }
 

internal/app/app_test.go

@@ -7,8 +7,6 @@ import (
 	"testing"
 	"time"
 
-	"charm.land/fantasy"
-
 	kit "github.com/mark3labs/kit/pkg/kit"
 )
 
@@ -574,13 +572,13 @@ func TestUpdateUsageFromTurnResult_skipsTotalsWhenStepUsageSeen(t *testing.T) {
 
 	app.updateUsageFromTurnResult(&kit.TurnResult{
 		Response: "ok",
-		TotalUsage: &fantasy.Usage{
+		TotalUsage: &kit.LLMUsage{
 			InputTokens:         999,
 			OutputTokens:        111,
 			CacheReadTokens:     7,
 			CacheCreationTokens: 3,
 		},
-		FinalUsage: &fantasy.Usage{InputTokens: 456},
+		FinalUsage: &kit.LLMUsage{InputTokens: 456},
 	}, "prompt", true)
 
 	usage.mu.Lock()
@@ -608,13 +606,13 @@ func TestUpdateUsageFromTurnResult_recordsWhenInputTokensZero(t *testing.T) {
 	// Simulate OpenAI-compatible behavior: all prompt tokens cached, InputTokens=0
 	app.updateUsageFromTurnResult(&kit.TurnResult{
 		Response: "ok",
-		TotalUsage: &fantasy.Usage{
+		TotalUsage: &kit.LLMUsage{
 			InputTokens:         0,   // All cached - subtracted from prompt
 			OutputTokens:        150, // Actual generated tokens
 			CacheReadTokens:     500, // Cache hit
 			CacheCreationTokens: 0,
 		},
-		FinalUsage: &fantasy.Usage{InputTokens: 0, OutputTokens: 150},
+		FinalUsage: &kit.LLMUsage{InputTokens: 0, OutputTokens: 150},
 	}, "prompt", false)
 
 	usage.mu.Lock()
@@ -642,11 +640,11 @@ func TestUpdateUsageFromTurnResult_contextTokensUsesInputOnly(t *testing.T) {
 
 	app.updateUsageFromTurnResult(&kit.TurnResult{
 		Response: "ok",
-		TotalUsage: &fantasy.Usage{
+		TotalUsage: &kit.LLMUsage{
 			InputTokens:  1000,
 			OutputTokens: 200,
 		},
-		FinalUsage: &fantasy.Usage{
+		FinalUsage: &kit.LLMUsage{
 			InputTokens:  1000, // Full context including history
 			OutputTokens: 200,
 		},

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 {
@@ -118,8 +123,8 @@ 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.

internal/app/messages.go

@@ -3,14 +3,14 @@ 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
+	messages []kit.LLMMessage
 }
 
 // NewMessageStore creates an empty MessageStore.
@@ -20,14 +20,14 @@ func NewMessageStore() *MessageStore {
 
 // 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 +36,22 @@ 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

@@ -4,16 +4,29 @@ 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),
+// makeTextMsg builds a minimal kit.LLMMessage using fantasy.NewUserMessage
+// or constructing with the given role.
+func makeTextMsg(role, text string) kit.LLMMessage {
+	return kit.LLMMessage{
+		Role:    kit.LLMMessageRole(role),
 		Content: []fantasy.MessagePart{fantasy.TextPart{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.(fantasy.TextPart); ok {
+			return tp.Text
+		}
+	}
+	return ""
+}
+
 // --------------------------------------------------------------------------
 // NewMessageStore / NewMessageStoreWithMessages
 // --------------------------------------------------------------------------
@@ -29,7 +42,7 @@ 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 +55,7 @@ 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 +65,8 @@ 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]))
 	}
 }
 
@@ -80,9 +92,8 @@ func TestAdd_preservesOrder(t *testing.T) {
 	}
 	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]))
 		}
 	}
 }
@@ -95,7 +106,7 @@ func TestReplace_swapsHistory(t *testing.T) {
 	s := NewMessageStore()
 	s.Add(makeTextMsg("user", "old"))
 
-	replacement := []fantasy.Message{
+	replacement := []kit.LLMMessage{
 		makeTextMsg("user", "new1"),
 		makeTextMsg("assistant", "new2"),
 	}
@@ -105,25 +116,22 @@ 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")}
+	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]))
 	}
 }
 
@@ -140,9 +148,8 @@ 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]))
 	}
 }
 
@@ -179,9 +186,8 @@ 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]))
 	}
 }
 

internal/app/options.go

@@ -67,10 +67,6 @@ 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

@@ -43,13 +43,30 @@ type OpenAICredentials struct {
 	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
@@ -57,19 +74,13 @@ 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 {
-	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
@@ -77,10 +88,7 @@ func (c *OpenAICredentials) IsExpired() bool {
 // to avoid authentication failures during operations. Returns false for API key
 // authentication or if no expiration is set.
 func (c *OpenAICredentials) 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)
 }
 
 // CredentialManager handles secure storage and retrieval of authentication credentials.

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

@@ -191,7 +191,6 @@ 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"`
@@ -403,10 +402,9 @@ 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/core/bash.go

@@ -7,6 +7,7 @@ import (
 	"io"
 	"os"
 	"os/exec"
+	"regexp"
 	"strings"
 	"sync"
 	"time"
@@ -39,20 +40,8 @@ func toolOutputCallbackFromContext(ctx context.Context) ToolOutputCallback {
 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"`
@@ -94,10 +83,8 @@ 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

internal/core/read.go

@@ -67,7 +67,7 @@ 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 +116,6 @@ 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
@@ -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/extensions/api.go

@@ -1022,7 +1022,7 @@ func (a *API) OnToolResult(handler func(ToolResultEvent, Context) *ToolResultRes
 	a.onToolResult(handler)
 }
 
-// OnSubagentStart registers a handler that fires when a spawn_subagent tool
+// 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)) {
@@ -1037,7 +1037,7 @@ func (a *API) OnSubagentChunk(handler func(SubagentChunkEvent, Context)) {
 	a.onSubagentChunk(handler)
 }
 
-// OnSubagentEnd registers a handler that fires when a spawn_subagent call
+// 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)
@@ -2046,9 +2046,9 @@ func (BeforeCompactResult) isResult() {}
 // Subagent lifecycle events (exposed to Yaegi — concrete structs)
 // ---------------------------------------------------------------------------
 
-// SubagentStartEvent fires when a spawn_subagent tool call begins executing.
+// SubagentStartEvent fires when a subagent tool call begins executing.
 type SubagentStartEvent struct {
-	// ToolCallID is the LLM-assigned ID of the spawn_subagent tool call.
+	// 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.
@@ -2088,7 +2088,7 @@ type SubagentChunkEvent struct {
 
 func (e SubagentChunkEvent) Type() EventType { return SubagentChunk }
 
-// SubagentEndEvent fires when a spawn_subagent tool call completes.
+// SubagentEndEvent fires when a subagent tool call completes.
 type SubagentEndEvent struct {
 	// ToolCallID matches the SubagentStartEvent.ToolCallID for this subagent.
 	ToolCallID string

internal/extensions/events.go

@@ -72,7 +72,7 @@ const (
 	// cancel compaction by returning Cancel=true.
 	BeforeCompact EventType = "before_compact"
 
-	// SubagentStart fires when a spawn_subagent tool call begins executing.
+	// SubagentStart fires when a subagent tool call begins executing.
 	// Carries the tool call ID and the task description.
 	SubagentStart EventType = "subagent_start"
 
@@ -80,7 +80,7 @@ const (
 	// subagent: text chunks, tool calls, tool results, etc.
 	SubagentChunk EventType = "subagent_chunk"
 
-	// SubagentEnd fires when a spawn_subagent tool call completes (success
+	// SubagentEnd fires when a subagent tool call completes (success
 	// or error). Carries the final response and any error message.
 	SubagentEnd EventType = "subagent_end"
 )

internal/extensions/loader.go

@@ -47,46 +47,56 @@ func LoadExtensions(extraPaths []string) ([]LoadedExtension, error) {
 	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 +107,14 @@ 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.

internal/extensions/subagent.go

@@ -173,10 +173,10 @@ type subagentJSONOutput struct {
 	} `json:"usage,omitempty"`
 }
 
-var subagentCounter uint64
+var subagentCounter atomic.Uint64
 
 func generateSubagentID() string {
-	n := atomic.AddUint64(&subagentCounter, 1)
+	n := subagentCounter.Add(1)
 	return fmt.Sprintf("sub-%d-%d", time.Now().UnixNano(), n)
 }
 

internal/extensions/watcher.go

@@ -0,0 +1,192 @@
+package extensions
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/charmbracelet/log"
+	"github.com/fsnotify/fsnotify"
+)
+
+// Watcher monitors extension directories for file changes and triggers
+// a reload callback when .go files are created, modified, or removed.
+// It uses fsnotify for kernel-level file notifications (inotify on Linux,
+// kqueue on macOS) with debouncing to coalesce rapid editor writes.
+type Watcher struct {
+	watcher  *fsnotify.Watcher
+	onReload func()
+	debounce time.Duration
+	cancel   context.CancelFunc
+	done     chan struct{}
+	mu       sync.Mutex
+}
+
+// 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) {
+	fsw, err := fsnotify.NewWatcher()
+	if err != nil {
+		return nil, fmt.Errorf("creating file watcher: %w", err)
+	}
+
+	for _, dir := range dirs {
+		// Watch the directory itself.
+		if err := fsw.Add(dir); err != nil {
+			log.Debug("watcher: skipping directory", "dir", dir, "err", err)
+			continue
+		}
+
+		// Also watch immediate subdirectories (for */main.go pattern).
+		entries, err := os.ReadDir(dir)
+		if err != nil {
+			continue
+		}
+		for _, entry := range entries {
+			if entry.IsDir() {
+				subdir := filepath.Join(dir, entry.Name())
+				if err := fsw.Add(subdir); err != nil {
+					log.Debug("watcher: skipping subdirectory", "dir", subdir, "err", err)
+				}
+			}
+		}
+	}
+
+	return &Watcher{
+		watcher:  fsw,
+		onReload: onReload,
+		debounce: 300 * time.Millisecond,
+		done:     make(chan struct{}),
+	}, nil
+}
+
+// Start begins watching for file changes. It blocks until the context
+// is cancelled or Close() is called. Typically called in a goroutine.
+func (w *Watcher) Start(ctx context.Context) {
+	w.mu.Lock()
+	ctx, w.cancel = context.WithCancel(ctx)
+	w.mu.Unlock()
+
+	defer close(w.done)
+
+	var timer *time.Timer
+	var timerC <-chan time.Time
+
+	for {
+		select {
+		case <-ctx.Done():
+			if timer != nil {
+				timer.Stop()
+			}
+			return
+
+		case event, ok := <-w.watcher.Events:
+			if !ok {
+				return
+			}
+
+			// Only care about .go files.
+			if !strings.HasSuffix(event.Name, ".go") {
+				continue
+			}
+
+			// React to write, create, remove, rename events.
+			if event.Op&(fsnotify.Write|fsnotify.Create|fsnotify.Remove|fsnotify.Rename) == 0 {
+				continue
+			}
+
+			log.Debug("watcher: file changed", "file", event.Name, "op", event.Op)
+
+			// Debounce: reset timer on each event.
+			if timer != nil {
+				timer.Stop()
+			}
+			timer = time.NewTimer(w.debounce)
+			timerC = timer.C
+
+		case <-timerC:
+			timerC = nil
+			timer = nil
+			log.Debug("watcher: reloading extensions")
+			w.onReload()
+
+		case err, ok := <-w.watcher.Errors:
+			if !ok {
+				return
+			}
+			log.Warn("watcher: error", "err", err)
+		}
+	}
+}
+
+// Close stops the watcher and releases resources.
+func (w *Watcher) Close() error {
+	w.mu.Lock()
+	cancel := w.cancel
+	w.mu.Unlock()
+
+	if cancel != nil {
+		cancel()
+	}
+
+	// Wait for the event loop to finish.
+	<-w.done
+	return w.watcher.Close()
+}
+
+// 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 {
+	var dirs []string
+	seen := make(map[string]bool)
+
+	add := func(dir string) {
+		abs, err := filepath.Abs(dir)
+		if err != nil {
+			return
+		}
+		if seen[abs] {
+			return
+		}
+
+		// Verify the directory exists.
+		info, err := os.Stat(abs)
+		if err != nil || !info.IsDir() {
+			return
+		}
+
+		seen[abs] = true
+		dirs = append(dirs, abs)
+	}
+
+	// Global extensions dir.
+	add(globalExtensionsDir())
+
+	// Project-local extensions dir.
+	add(filepath.Join(".kit", "extensions"))
+
+	// Explicit paths that are directories.
+	for _, p := range extraPaths {
+		info, err := os.Stat(p)
+		if err != nil {
+			continue
+		}
+		if info.IsDir() {
+			add(p)
+		} else {
+			// For explicit files, watch the parent directory.
+			add(filepath.Dir(p))
+		}
+	}
+
+	return dirs
+}

internal/extensions/watcher_test.go

@@ -0,0 +1,158 @@
+package extensions
+
+import (
+	"os"
+	"path/filepath"
+	"sync/atomic"
+	"testing"
+	"time"
+)
+
+func TestWatcher_ReloadsOnGoFileChange(t *testing.T) {
+	dir := t.TempDir()
+
+	// Write an initial extension file.
+	extFile := filepath.Join(dir, "test.go")
+	if err := os.WriteFile(extFile, []byte("package main\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	var reloadCount atomic.Int32
+
+	w, err := NewWatcher([]string{dir}, func() {
+		reloadCount.Add(1)
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	go w.Start(t.Context())
+
+	// Modify the file.
+	time.Sleep(50 * time.Millisecond) // let watcher settle
+	if err := os.WriteFile(extFile, []byte("package main\n// changed\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	// Wait for debounce (300ms) + margin.
+	time.Sleep(600 * time.Millisecond)
+
+	if got := reloadCount.Load(); got != 1 {
+		t.Errorf("expected 1 reload, got %d", got)
+	}
+
+	if err := w.Close(); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestWatcher_IgnoresNonGoFiles(t *testing.T) {
+	dir := t.TempDir()
+
+	var reloadCount atomic.Int32
+
+	w, err := NewWatcher([]string{dir}, func() {
+		reloadCount.Add(1)
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	go w.Start(t.Context())
+
+	// Write a non-.go file.
+	time.Sleep(50 * time.Millisecond)
+	txtFile := filepath.Join(dir, "notes.txt")
+	if err := os.WriteFile(txtFile, []byte("hello"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	// Wait past the debounce window.
+	time.Sleep(600 * time.Millisecond)
+
+	if got := reloadCount.Load(); got != 0 {
+		t.Errorf("expected 0 reloads for .txt file, got %d", got)
+	}
+
+	if err := w.Close(); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestWatcher_Debounces(t *testing.T) {
+	dir := t.TempDir()
+
+	extFile := filepath.Join(dir, "ext.go")
+	if err := os.WriteFile(extFile, []byte("package main\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	var reloadCount atomic.Int32
+
+	w, err := NewWatcher([]string{dir}, func() {
+		reloadCount.Add(1)
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	go w.Start(t.Context())
+
+	time.Sleep(50 * time.Millisecond)
+
+	// Rapid-fire writes (simulating editor save: write temp, rename, etc.).
+	for range 5 {
+		if err := os.WriteFile(extFile, []byte("package main\n// changed\n"), 0o644); err != nil {
+			t.Fatal(err)
+		}
+		time.Sleep(50 * time.Millisecond)
+	}
+
+	// Wait for debounce to fire.
+	time.Sleep(600 * time.Millisecond)
+
+	if got := reloadCount.Load(); got != 1 {
+		t.Errorf("expected 1 debounced reload, got %d", got)
+	}
+
+	if err := w.Close(); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestWatchedDirs_Deduplicates(t *testing.T) {
+	dir := t.TempDir()
+	dirs := WatchedDirs([]string{dir, dir})
+
+	count := 0
+	for _, d := range dirs {
+		abs, _ := filepath.Abs(dir)
+		if d == abs {
+			count++
+		}
+	}
+	if count != 1 {
+		t.Errorf("expected directory to appear once, got %d", count)
+	}
+}
+
+func TestWatchedDirs_FileParent(t *testing.T) {
+	dir := t.TempDir()
+	file := filepath.Join(dir, "ext.go")
+	if err := os.WriteFile(file, []byte("package main\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	dirs := WatchedDirs([]string{file})
+
+	abs, _ := filepath.Abs(dir)
+	found := false
+	for _, d := range dirs {
+		if d == abs {
+			found = true
+		}
+	}
+	if !found {
+		t.Errorf("expected parent dir %s in watched dirs %v", abs, dirs)
+	}
+}

internal/extensions/wrapper.go

@@ -42,14 +42,14 @@ func ExtensionToolsAsFantasy(defs []ToolDef, runner *Runner) []fantasy.AgentTool
 
 // coreToolKinds maps built-in tool names to their kind classification.
 var coreToolKinds = map[string]string{
-	"bash":           "execute",
-	"edit":           "edit",
-	"write":          "edit",
-	"read":           "read",
-	"ls":             "read",
-	"grep":           "search",
-	"find":           "search",
-	"spawn_subagent": "agent",
+	"bash":     "execute",
+	"edit":     "edit",
+	"write":    "edit",
+	"read":     "read",
+	"ls":       "read",
+	"grep":     "search",
+	"find":     "search",
+	"subagent": "agent",
 }
 
 // toolKindFor returns the ToolKind for a given tool name, defaulting to

internal/kitsetup/setup.go

@@ -40,6 +40,24 @@ type AgentSetupOptions struct {
 	// wrapping. Used by the SDK hook system. Both wrappers compose:
 	// extension wrapper runs first (inner), then this wrapper (outer).
 	ToolWrapper func([]fantasy.AgentTool) []fantasy.AgentTool
+
+	// ProviderConfig, when non-nil, is used directly instead of calling
+	// BuildProviderConfig(). Callers that already hold viperInitMu can
+	// pre-build this and release the lock before calling SetupAgent, so the
+	// slow agent/MCP initialisation runs concurrently with other New() calls.
+	ProviderConfig *models.ProviderConfig
+	// Debug enables debug logging. When zero-value, viper is consulted.
+	// Only meaningful when ProviderConfig is also set.
+	Debug bool
+	// NoExtensions skips extension loading. When false, viper is consulted.
+	// Only meaningful when ProviderConfig is also set.
+	NoExtensions bool
+	// MaxSteps overrides the agent step limit. 0 means use viper value.
+	// Only meaningful when ProviderConfig is also set.
+	MaxSteps int
+	// StreamingEnabled controls streaming. Only meaningful when ProviderConfig
+	// is also set.
+	StreamingEnabled bool
 }
 
 // AgentSetupResult bundles the created agent and any debug logger so the caller
@@ -88,15 +106,36 @@ func BuildProviderConfig() (*models.ProviderConfig, string, error) {
 // SetupAgent creates an agent from the current viper state + the provided
 // options. It wraps BuildProviderConfig and agent.CreateAgent.
 func SetupAgent(ctx context.Context, opts AgentSetupOptions) (*AgentSetupResult, error) {
-	modelConfig, systemPrompt, err := BuildProviderConfig()
-	if err != nil {
-		return nil, err
+	var modelConfig *models.ProviderConfig
+	var systemPrompt string
+
+	if opts.ProviderConfig != nil {
+		// Pre-built config supplied by caller (e.g. Kit.New after releasing
+		// viperInitMu). Use it directly — no viper reads needed here.
+		modelConfig = opts.ProviderConfig
+		systemPrompt = modelConfig.SystemPrompt
+	} else {
+		var err error
+		modelConfig, systemPrompt, err = BuildProviderConfig()
+		if err != nil {
+			return nil, err
+		}
 	}
 
+	// Resolve debug / no-extensions / max-steps / streaming: prefer explicit
+	// fields (set when ProviderConfig was pre-built) over viper fallback.
+	debugEnabled := opts.Debug || viper.GetBool("debug")
+	noExtensions := opts.NoExtensions || viper.GetBool("no-extensions")
+	maxSteps := opts.MaxSteps
+	if maxSteps == 0 {
+		maxSteps = viper.GetInt("max-steps")
+	}
+	streamingEnabled := opts.StreamingEnabled || viper.GetBool("stream")
+
 	// Create the appropriate debug logger.
 	var debugLogger tools.DebugLogger
 	var bufferedLogger *tools.BufferedDebugLogger
-	if viper.GetBool("debug") {
+	if debugEnabled {
 		if opts.UseBufferedLogger {
 			bufferedLogger = tools.NewBufferedDebugLogger(true)
 			debugLogger = bufferedLogger
@@ -108,7 +147,7 @@ func SetupAgent(ctx context.Context, opts AgentSetupOptions) (*AgentSetupResult,
 	// Load extensions unless --no-extensions is set.
 	var extRunner *extensions.Runner
 	var extCreationOpts extensionCreationOpts
-	if !viper.GetBool("no-extensions") {
+	if !noExtensions {
 		var extErr error
 		extRunner, extCreationOpts, extErr = loadExtensions()
 		if extErr != nil {
@@ -140,8 +179,8 @@ func SetupAgent(ctx context.Context, opts AgentSetupOptions) (*AgentSetupResult,
 		ModelConfig:      modelConfig,
 		MCPConfig:        opts.MCPConfig,
 		SystemPrompt:     systemPrompt,
-		MaxSteps:         viper.GetInt("max-steps"),
-		StreamingEnabled: viper.GetBool("stream"),
+		MaxSteps:         maxSteps,
+		StreamingEnabled: streamingEnabled,
 		ShowSpinner:      opts.ShowSpinner,
 		Quiet:            opts.Quiet,
 		SpinnerFunc:      opts.SpinnerFunc,

internal/message/content.go

@@ -4,12 +4,18 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"regexp"
 	"strings"
 	"time"
 
 	"charm.land/fantasy"
 )
 
+// thinkTagRegex matches  ...  tags that some models (Qwen, DeepSeek) wrap
+// reasoning content in. Used to strip these tags from text content.
+// The (?s) flag makes . match newlines.
+var thinkTagRegex = regexp.MustCompile(`(?s)` + `` + `think` + `` + `(.*?)` + `` + `/think` + ``)
+
 // sanitizeToolCallID ensures the ID matches Anthropic's required pattern:
 // ^[a-zA-Z0-9_-]+$ (alphanumeric, underscores, and hyphens only).
 // Invalid characters are replaced with underscores.
@@ -115,9 +121,9 @@ const (
 )
 
 // Message is a single conversation message containing a heterogeneous slice
-// of ContentPart blocks. This design (borrowed from crush) enables a single
-// assistant message to carry text, reasoning, and multiple tool calls as
-// discrete, typed blocks rather than flattening everything into strings.
+// of ContentPart blocks. This design enables a single assistant message to
+// carry text, reasoning, and multiple tool calls as discrete, typed blocks
+// rather than flattening everything into strings.
 type Message struct {
 	ID        string        `json:"id"`
 	Role      MessageRole   `json:"role"`
@@ -312,12 +318,18 @@ func UnmarshalParts(data []byte) ([]ContentPart, error) {
 	return parts, nil
 }
 
-// --- Fantasy bridge ---
+// --- LLM bridge ---
 
-// ToFantasyMessages converts a Message to one or more fantasy.Message values.
-// An assistant message with tool calls produces a single fantasy message with
+// ToLLMMessages converts a Message to one or more LLM message values.
+// An assistant message with tool calls produces a single message with
 // mixed TextPart and ToolCallPart content. Tool-role messages produce
 // ToolResultPart entries.
+func (m *Message) ToLLMMessages() []fantasy.Message {
+	return m.ToFantasyMessages()
+}
+
+// Deprecated: Use ToLLMMessages instead.
+// ToFantasyMessages converts a Message to one or more LLM message values.
 func (m *Message) ToFantasyMessages() []fantasy.Message {
 	switch m.Role {
 	case RoleAssistant:
@@ -416,7 +428,14 @@ func (m *Message) ToFantasyMessages() []fantasy.Message {
 	}
 }
 
-// FromFantasyMessage converts a fantasy.Message into our Message type,
+// FromLLMMessage converts an LLM message into our Message type,
+// extracting all content parts into the appropriate block types.
+func FromLLMMessage(msg fantasy.Message) Message {
+	return FromFantasyMessage(msg)
+}
+
+// Deprecated: Use FromLLMMessage instead.
+// FromFantasyMessage converts an LLM message into our Message type,
 // extracting all content parts into the appropriate block types.
 func FromFantasyMessage(msg fantasy.Message) Message {
 	m := Message{
@@ -430,7 +449,11 @@ func FromFantasyMessage(msg fantasy.Message) Message {
 		switch p := part.(type) {
 		case fantasy.TextPart:
 			if p.Text != "" {
-				m.Parts = append(m.Parts, TextContent{Text: p.Text})
+				// Strip  ...  tags that some models wrap reasoning in
+				cleanedText := thinkTagRegex.ReplaceAllString(p.Text, "")
+				if cleanedText != "" {
+					m.Parts = append(m.Parts, TextContent{Text: cleanedText})
+				}
 			}
 		case fantasy.ToolCallPart:
 			m.Parts = append(m.Parts, ToolCall{

internal/models/cache_options.go

@@ -0,0 +1,87 @@
+package models
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+	"maps"
+	"os"
+
+	"charm.land/fantasy"
+	"charm.land/fantasy/providers/openai"
+)
+
+// buildCacheProviderOptions returns caching options for supported models.
+// Caching is enabled by default for all supported models to reduce costs.
+// Set KIT_DISABLE_CACHE=1 or ProviderConfig.DisableCaching=true to opt out.
+func buildCacheProviderOptions(modelInfo *ModelInfo, config *ProviderConfig) fantasy.ProviderOptions {
+	// Check explicit opt-out via config
+	if config.DisableCaching {
+		return nil
+	}
+
+	// Check global opt-out via environment
+	if os.Getenv("KIT_DISABLE_CACHE") != "" {
+		return nil
+	}
+
+	// Check if model supports caching
+	if modelInfo == nil || !modelInfo.SupportsCaching() {
+		return nil
+	}
+
+	switch modelInfo.CacheType() {
+	case "anthropic-ephemeral":
+		// Provider-level Anthropic caching disabled - use message-level caching instead.
+		return nil
+	case "openai-prompt-cache":
+		return buildOpenAICacheOptions(config, modelInfo.ID)
+	case "google-cached-content":
+		// Google caching not yet implemented.
+		return nil
+	default:
+		return nil
+	}
+}
+
+// buildOpenAICacheOptions enables prompt caching for OpenAI models.
+// Uses a deterministic cache key based on system prompt and model ID.
+func buildOpenAICacheOptions(config *ProviderConfig, modelID string) fantasy.ProviderOptions {
+	cacheKey := generateCacheKey(config.SystemPrompt, modelID)
+
+	return fantasy.ProviderOptions{
+		openai.Name: &openai.ProviderOptions{
+			PromptCacheKey: &cacheKey,
+		},
+	}
+}
+
+// generateCacheKey creates a deterministic cache key from system prompt and model.
+// This ensures the same system prompt + model combination gets cache hits.
+func generateCacheKey(systemPrompt, modelID string) string {
+	if systemPrompt == "" {
+		systemPrompt = "default"
+	}
+
+	h := sha256.New()
+	h.Write([]byte(systemPrompt))
+	h.Write([]byte(modelID))
+
+	// Prefix with "kit-" to identify KIT-generated cache keys
+	return "kit-" + hex.EncodeToString(h.Sum(nil))[:24]
+}
+
+// mergeProviderOptions merges multiple ProviderOptions maps.
+// Later maps take precedence over earlier ones.
+func mergeProviderOptions(opts ...fantasy.ProviderOptions) fantasy.ProviderOptions {
+	result := make(fantasy.ProviderOptions)
+
+	for _, opt := range opts {
+		maps.Copy(result, opt)
+	}
+
+	if len(result) == 0 {
+		return nil
+	}
+
+	return result
+}

internal/models/cache_options_test.go

@@ -0,0 +1,248 @@
+package models
+
+import (
+	"os"
+	"testing"
+
+	"charm.land/fantasy"
+)
+
+func TestModelInfo_SupportsCaching(t *testing.T) {
+	tests := []struct {
+		name     string
+		family   string
+		expected bool
+	}{
+		{"Claude model", "claude-3-5-sonnet", true},
+		{"Claude 4 model", "claude-4-opus", true},
+		{"GPT model", "gpt-4", true},
+		{"GPT-5 model", "gpt-5", true},
+		{"O1 model", "o1", true},
+		{"O3 model", "o3", true},
+		{"O4 model", "o4-mini", true},
+		{"Codex model", "codex", true},
+		{"Gemini model", "gemini-2.5-pro", true},
+		{"Gemini 1.5 model", "gemini-1.5-flash", true},
+		{"Llama model", "llama-3", false},
+		{"Unknown model", "unknown", false},
+		{"Empty family", "", false},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			m := &ModelInfo{Family: tt.family}
+			if got := m.SupportsCaching(); got != tt.expected {
+				t.Errorf("ModelInfo.SupportsCaching() = %v, want %v", got, tt.expected)
+			}
+		})
+	}
+}
+
+func TestModelInfo_CacheType(t *testing.T) {
+	tests := []struct {
+		name     string
+		family   string
+		expected string
+	}{
+		{"Claude model", "claude-3-5-sonnet", "anthropic-ephemeral"},
+		{"GPT model", "gpt-4", "openai-prompt-cache"},
+		{"O1 model", "o1", "openai-prompt-cache"},
+		{"Gemini model", "gemini-2.5-pro", "google-cached-content"},
+		{"Unknown model", "llama-3", ""},
+		{"Empty family", "", ""},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			m := &ModelInfo{Family: tt.family}
+			if got := m.CacheType(); got != tt.expected {
+				t.Errorf("ModelInfo.CacheType() = %v, want %v", got, tt.expected)
+			}
+		})
+	}
+}
+
+func TestGenerateCacheKey(t *testing.T) {
+	key1 := generateCacheKey("system prompt", "model-id")
+	key2 := generateCacheKey("system prompt", "model-id")
+	if key1 != key2 {
+		t.Errorf("generateCacheKey should be deterministic: got %q and %q", key1, key2)
+	}
+
+	key3 := generateCacheKey("different prompt", "model-id")
+	if key1 == key3 {
+		t.Errorf("generateCacheKey should produce different keys for different inputs")
+	}
+
+	key4 := generateCacheKey("", "model-id")
+	key5 := generateCacheKey("default", "model-id")
+	if key4 != key5 {
+		t.Errorf("generateCacheKey should treat empty prompt as 'default'")
+	}
+
+	if len(key1) < 4 || key1[:4] != "kit-" {
+		t.Errorf("generateCacheKey should produce keys with 'kit-' prefix, got %q", key1)
+	}
+}
+
+func TestBuildCacheProviderOptions_Disabled(t *testing.T) {
+	config := &ProviderConfig{DisableCaching: true}
+	modelInfo := &ModelInfo{Family: "claude-3", ID: "claude-3-opus"}
+
+	if opts := buildCacheProviderOptions(modelInfo, config); opts != nil {
+		t.Errorf("buildCacheProviderOptions should return nil when DisableCaching=true")
+	}
+}
+
+func TestBuildCacheProviderOptions_EnvironmentVariable(t *testing.T) {
+	_ = os.Setenv("KIT_DISABLE_CACHE", "1")
+	defer func() { _ = os.Unsetenv("KIT_DISABLE_CACHE") }()
+
+	config := &ProviderConfig{DisableCaching: false}
+	modelInfo := &ModelInfo{Family: "claude-3", ID: "claude-3-opus"}
+
+	if opts := buildCacheProviderOptions(modelInfo, config); opts != nil {
+		t.Errorf("buildCacheProviderOptions should return nil when KIT_DISABLE_CACHE is set")
+	}
+}
+
+func TestBuildCacheProviderOptions_UnsupportedModel(t *testing.T) {
+	config := &ProviderConfig{DisableCaching: false}
+	modelInfo := &ModelInfo{Family: "llama-3", ID: "llama-3-70b"}
+
+	if opts := buildCacheProviderOptions(modelInfo, config); opts != nil {
+		t.Errorf("buildCacheProviderOptions should return nil for unsupported model families")
+	}
+}
+
+func TestBuildCacheProviderOptions_NilModelInfo(t *testing.T) {
+	config := &ProviderConfig{DisableCaching: false}
+
+	if opts := buildCacheProviderOptions(nil, config); opts != nil {
+		t.Errorf("buildCacheProviderOptions should return nil when modelInfo is nil")
+	}
+}
+
+func TestBuildCacheProviderOptions_Anthropic(t *testing.T) {
+	_ = os.Unsetenv("KIT_DISABLE_CACHE")
+
+	config := &ProviderConfig{DisableCaching: false}
+	modelInfo := &ModelInfo{Family: "claude-3", ID: "claude-3-opus"}
+
+	opts := buildCacheProviderOptions(modelInfo, config)
+	// Provider-level Anthropic caching is disabled; message-level caching is used instead
+	if opts != nil {
+		t.Logf("Provider-level Anthropic caching disabled; using message-level caching")
+	}
+}
+
+func TestBuildCacheProviderOptions_OpenAI(t *testing.T) {
+	_ = os.Unsetenv("KIT_DISABLE_CACHE")
+
+	config := &ProviderConfig{
+		DisableCaching: false,
+		SystemPrompt:   "test system prompt",
+	}
+	modelInfo := &ModelInfo{Family: "gpt-4", ID: "gpt-4o"}
+
+	opts := buildCacheProviderOptions(modelInfo, config)
+	if opts == nil {
+		t.Fatalf("buildCacheProviderOptions should return options for OpenAI models")
+	}
+
+	if _, ok := opts["openai"]; !ok {
+		t.Errorf("buildCacheProviderOptions should include 'openai' key for GPT models")
+	}
+}
+
+func TestCachingPriorityOverThinking(t *testing.T) {
+	_ = os.Unsetenv("KIT_DISABLE_CACHE")
+
+	// Anthropic uses message-level caching; provider-level returns nil
+	config1 := &ProviderConfig{
+		DisableCaching: false,
+		ThinkingLevel:  ThinkingOff,
+	}
+	modelInfo1 := &ModelInfo{Family: "claude-3", ID: "claude-3-opus"}
+	opts1 := buildCacheProviderOptions(modelInfo1, config1)
+	if opts1 != nil {
+		t.Logf("Provider-level Anthropic caching disabled; using message-level caching")
+	}
+
+	// OpenAI provider-level caching works with thinking enabled
+	config2 := &ProviderConfig{
+		DisableCaching: false,
+		SystemPrompt:   "test prompt",
+		ThinkingLevel:  ThinkingMedium,
+	}
+	modelInfo2 := &ModelInfo{Family: "gpt-4", ID: "gpt-4o"}
+	opts2 := buildCacheProviderOptions(modelInfo2, config2)
+	if opts2 == nil {
+		t.Errorf("OpenAI caching should work with thinking enabled")
+	}
+
+	// OpenAI caching also works with thinking disabled
+	config3 := &ProviderConfig{
+		DisableCaching: false,
+		SystemPrompt:   "test prompt",
+		ThinkingLevel:  ThinkingOff,
+	}
+	opts3 := buildCacheProviderOptions(modelInfo2, config3)
+	if opts3 == nil {
+		t.Errorf("OpenAI caching should work when thinking is OFF")
+	}
+}
+
+func TestMergeProviderOptions(t *testing.T) {
+	opts1 := fantasy.ProviderOptions{
+		"provider1": &testProviderData{value: "value1"},
+	}
+	opts2 := fantasy.ProviderOptions{
+		"provider2": &testProviderData{value: "value2"},
+	}
+
+	merged := mergeProviderOptions(opts1, opts2)
+
+	if len(merged) != 2 {
+		t.Errorf("mergeProviderOptions should combine options from multiple maps, got %d items", len(merged))
+	}
+
+	if _, ok := merged["provider1"]; !ok {
+		t.Errorf("merged options should contain 'provider1' key")
+	}
+
+	if _, ok := merged["provider2"]; !ok {
+		t.Errorf("merged options should contain 'provider2' key")
+	}
+
+	// Later options should override earlier ones
+	opts3 := fantasy.ProviderOptions{
+		"provider1": &testProviderData{value: "overridden"},
+	}
+	merged2 := mergeProviderOptions(opts1, opts3)
+
+	if data, ok := merged2["provider1"].(*testProviderData); ok {
+		if data.value != "overridden" {
+			t.Errorf("later options should override earlier ones, got %q", data.value)
+		}
+	}
+
+	if mergeProviderOptions() != nil {
+		t.Errorf("mergeProviderOptions with no args should return nil")
+	}
+}
+
+// testProviderData is a simple implementation of ProviderOptionsData for testing
+type testProviderData struct {
+	value string
+}
+
+func (t *testProviderData) Options() {}
+
+func (t *testProviderData) MarshalJSON() ([]byte, error) {
+	return []byte(`"` + t.value + `"`), nil
+}
+
+func (t *testProviderData) UnmarshalJSON(data []byte) error {
+	return nil
+}

internal/models/modelsdb.go

@@ -48,10 +48,10 @@ type modelsDBLimit struct {
 	Output  int `json:"output"`
 }
 
-// npmToFantasyProvider maps npm package names from models.dev to fantasy
+// npmToLLMProvider maps npm package names from models.dev to LLM
 // provider identifiers. Providers not in this map but with an api URL
 // can be auto-routed through openaicompat.
-var npmToFantasyProvider = map[string]string{
+var npmToLLMProvider = map[string]string{
 	"@ai-sdk/anthropic":               "anthropic",
 	"@ai-sdk/openai":                  "openai",
 	"@ai-sdk/google":                  "google",

internal/models/providers.go

@@ -10,6 +10,7 @@ import (
 	"maps"
 	"net/http"
 	"os"
+	"regexp"
 	"strings"
 	"time"
 
@@ -22,6 +23,7 @@ import (
 	"charm.land/fantasy/providers/openaicompat"
 	"charm.land/fantasy/providers/openrouter"
 	"charm.land/fantasy/providers/vercel"
+	openaisdk "github.com/charmbracelet/openai-go"
 
 	"github.com/mark3labs/kit/internal/auth"
 	"github.com/mark3labs/kit/internal/ui/progress"
@@ -155,6 +157,7 @@ type ProviderConfig struct {
 	MainGPU        *int32
 	TLSSkipVerify  bool
 	ThinkingLevel  ThinkingLevel
+	DisableCaching bool // Opt-out: set to true to disable automatic prompt caching
 }
 
 // ProviderResult contains the result of provider creation.
@@ -237,30 +240,59 @@ func CreateProvider(ctx context.Context, config *ProviderConfig) (*ProviderResul
 		validateModelConfig(config, modelInfo)
 	}
 
+	// Create the base provider
+	var result *ProviderResult
+	var createErr error
+
 	switch provider {
 	case "anthropic":
-		return createAnthropicProvider(ctx, config, modelName)
+		result, createErr = createAnthropicProvider(ctx, config, modelName)
 	case "openai":
-		return createOpenAIProvider(ctx, config, modelName)
+		result, createErr = createOpenAIProvider(ctx, config, modelName)
 	case "google", "gemini":
-		return createGoogleProvider(ctx, config, modelName)
+		result, createErr = createGoogleProvider(ctx, config, modelName)
 	case "ollama":
-		return createOllamaProvider(ctx, config, modelName)
+		result, createErr = createOllamaProvider(ctx, config, modelName)
 	case "azure":
-		return createAzureProvider(ctx, config, modelName)
+		result, createErr = createAzureProvider(ctx, config, modelName)
 	case "google-vertex-anthropic":
-		return createVertexAnthropicProvider(ctx, config, modelName)
+		result, createErr = createVertexAnthropicProvider(ctx, config, modelName)
 	case "openrouter":
-		return createOpenRouterProvider(ctx, config, modelName)
+		result, createErr = createOpenRouterProvider(ctx, config, modelName)
 	case "bedrock":
-		return createBedrockProvider(ctx, config, modelName)
+		result, createErr = createBedrockProvider(ctx, config, modelName)
 	case "vercel":
-		return createVercelProvider(ctx, config, modelName)
+		result, createErr = createVercelProvider(ctx, config, modelName)
 	case "custom":
-		return createCustomProvider(ctx, config, modelName)
+		result, createErr = createCustomProvider(ctx, config, modelName)
 	default:
-		return autoRouteProvider(ctx, config, provider, modelName, registry)
+		result, createErr = autoRouteProvider(ctx, config, provider, modelName, registry)
 	}
+
+	if createErr != nil {
+		return nil, createErr
+	}
+
+	// AUTOMATICALLY ENABLE CACHING for supported models (unless disabled).
+	// This works for BOTH native and auto-routed providers by detecting
+	// the model family from the model metadata.
+	if cacheOpts := buildCacheProviderOptions(modelInfo, config); cacheOpts != nil {
+		if result.ProviderOptions == nil {
+			result.ProviderOptions = cacheOpts
+		} else {
+			// Merge cache options with existing provider options.
+			// Only add cache options for providers that don't already have
+			// options set, to avoid type conflicts (e.g., Anthropic has
+			// different types for regular options vs cache control options).
+			for k, v := range cacheOpts {
+				if _, exists := result.ProviderOptions[k]; !exists {
+					result.ProviderOptions[k] = v
+				}
+			}
+		}
+	}
+
+	return result, nil
 }
 
 // autoRouteProvider attempts to create a provider by looking up its npm package
@@ -280,14 +312,14 @@ func autoRouteProvider(ctx context.Context, config *ProviderConfig, provider, mo
 		npmPackage = modelInfo.ProviderNPM
 	}
 
-	// Determine the fantasy provider for this npm package
-	fantasyProvider := npmToFantasyProvider[npmPackage]
-	if fantasyProvider == "" && providerInfo.API != "" {
+	// Determine the LLM provider for this npm package
+	llmProvider := npmToLLMProvider[npmPackage]
+	if llmProvider == "" && providerInfo.API != "" {
 		// Unknown npm but has API URL → route through openaicompat
-		fantasyProvider = "openaicompat"
+		llmProvider = "openaicompat"
 	}
 
-	switch fantasyProvider {
+	switch llmProvider {
 	case "openaicompat":
 		return createAutoRoutedOpenAICompatProvider(ctx, config, modelName, providerInfo)
 	case "anthropic":
@@ -301,7 +333,7 @@ func autoRouteProvider(ctx context.Context, config *ProviderConfig, provider, mo
 		}
 		return createAutoRoutedOpenAIProvider(ctx, config, modelName, providerInfo)
 	default:
-		return nil, fmt.Errorf("unsupported provider: %s (npm: %s has no fantasy mapping)", provider, npmPackage)
+		return nil, fmt.Errorf("unsupported provider: %s (npm: %s has no LLM provider mapping)", provider, npmPackage)
 	}
 }
 
@@ -510,10 +542,15 @@ func thinkingLevelToReasoningEffort(level ThinkingLevel) *openai.ReasoningEffort
 // SendReasoning to true and configures the thinking budget. For thinking-off
 // or non-reasoning models the returned map is nil.
 //
+// NOTE: With message-level caching, thinking and caching can work together.
+// Message-level cache control (ProviderCacheControlOptions) doesn't conflict
+// with provider-level thinking options (ProviderOptions).
+//
 // Anthropic requires max_tokens > thinking.budget_tokens. If the configured
 // MaxTokens is too low, it is bumped to budget + 4096 to leave room for the
 // actual response.
 func buildAnthropicProviderOptions(config *ProviderConfig, modelName string) fantasy.ProviderOptions {
+	// Thinking is OFF by default. If user hasn't explicitly enabled it, return nil.
 	if config.ThinkingLevel == "" || config.ThinkingLevel == ThinkingOff {
 		return nil
 	}
@@ -963,6 +1000,133 @@ func createVercelProvider(ctx context.Context, config *ProviderConfig, modelName
 	return &ProviderResult{Model: model}, nil
 }
 
+// thinkTagRegex matches <think>...</think> tags for extracting reasoning content
+// from models that wrap thinking in XML-like tags (e.g., Qwen, DeepSeek).
+var thinkTagRegex = regexp.MustCompile(`(?s)<think>(.*?)</think>`)
+
+// customExtraContentFunc extracts reasoning from <think> tags in the content field.
+// This handles models like Qwen and DeepSeek that return reasoning wrapped in XML tags
+// rather than using a separate reasoning_content field.
+func customExtraContentFunc(choice openaisdk.ChatCompletionChoice) []fantasy.Content {
+	var content []fantasy.Content
+	if choice.Message.Content == "" {
+		return content
+	}
+
+	// Check for <think> tags in the content
+	matches := thinkTagRegex.FindStringSubmatch(choice.Message.Content)
+	if len(matches) > 1 {
+		// Found reasoning content in <think> tags
+		reasoning := strings.TrimSpace(matches[1])
+		if reasoning != "" {
+			content = append(content, fantasy.ReasoningContent{
+				Text: reasoning,
+			})
+		}
+	}
+
+	return content
+}
+
+// customStreamExtraFunc handles streaming responses with <think> tags.
+// It extracts reasoning content and emits proper reasoning events.
+func customStreamExtraFunc(
+	chunk openaisdk.ChatCompletionChunk,
+	yield func(fantasy.StreamPart) bool,
+	ctx map[string]any,
+) (map[string]any, bool) {
+	if len(chunk.Choices) == 0 {
+		return ctx, true
+	}
+
+	const reasoningStartedKey = "reasoning_started"
+	const reasoningBufferKey = "reasoning_buffer"
+	const inThinkTagKey = "in_think_tag"
+
+	reasoningStarted, _ := ctx[reasoningStartedKey].(bool)
+	inThinkTag, _ := ctx[inThinkTagKey].(bool)
+	reasoningBuffer, _ := ctx[reasoningBufferKey].(string)
+
+	for i, choice := range chunk.Choices {
+		content := choice.Delta.Content
+		if content == "" {
+			continue
+		}
+
+		// Check for <think> tag start
+		if strings.Contains(content, "<think>") {
+			inThinkTag = true
+			ctx[inThinkTagKey] = true
+
+			// Emit reasoning start event
+			if !reasoningStarted {
+				reasoningStarted = true
+				ctx[reasoningStartedKey] = true
+				if !yield(fantasy.StreamPart{
+					Type: fantasy.StreamPartTypeReasoningStart,
+					ID:   fmt.Sprintf("%d", i),
+				}) {
+					return ctx, false
+				}
+			}
+
+			// Extract content after <think>
+			parts := strings.SplitN(content, "<think>", 2)
+			if len(parts) > 1 && parts[1] != "" {
+				reasoningBuffer += parts[1]
+				ctx[reasoningBufferKey] = reasoningBuffer
+			}
+			continue
+		}
+
+		// Check for </think> tag end
+		if strings.Contains(content, "</think>") {
+			inThinkTag = false
+			ctx[inThinkTagKey] = false
+
+			// Extract content before </think>
+			parts := strings.SplitN(content, "</think>", 2)
+			if len(parts) > 0 {
+				reasoningBuffer += parts[0]
+			}
+
+			// Emit the accumulated reasoning
+			if reasoningBuffer != "" {
+				if !yield(fantasy.StreamPart{
+					Type:  fantasy.StreamPartTypeReasoningDelta,
+					ID:    fmt.Sprintf("%d", i),
+					Delta: reasoningBuffer,
+				}) {
+					return ctx, false
+				}
+				ctx[reasoningBufferKey] = ""
+			}
+
+			// Emit reasoning end
+			if !yield(fantasy.StreamPart{
+				Type: fantasy.StreamPartTypeReasoningEnd,
+				ID:   fmt.Sprintf("%d", i),
+			}) {
+				return ctx, false
+			}
+			continue
+		}
+
+		// Accumulate reasoning content while in think tag
+		if inThinkTag {
+			reasoningBuffer += content
+			ctx[reasoningBufferKey] = reasoningBuffer
+		}
+	}
+
+	return ctx, true
+}
+
+// customToPromptFunc converts prompts to OpenAI format using the default conversion.
+func customToPromptFunc(prompt fantasy.Prompt, systemPrompt, user string) ([]openaisdk.ChatCompletionMessageParamUnion, []fantasy.CallWarning) {
+	return openai.DefaultToPrompt(prompt, systemPrompt, user)
+}
+
 func createCustomProvider(ctx context.Context, config *ProviderConfig, modelName string) (*ProviderResult, error) {
 	if config.ProviderURL == "" {
 		return nil, fmt.Errorf("custom provider requires --provider-url")
@@ -977,16 +1141,23 @@ func createCustomProvider(ctx context.Context, config *ProviderConfig, modelName
 		apiKey = "custom"
 	}
 
-	var opts []openaicompat.Option
-	opts = append(opts, openaicompat.WithBaseURL(config.ProviderURL))
-	opts = append(opts, openaicompat.WithAPIKey(apiKey))
-	opts = append(opts, openaicompat.WithName("custom"))
+	// Use the openai provider directly with custom hooks to handle <think> tags
+	// from models like Qwen and DeepSeek that wrap reasoning in XML tags.
+	var opts []openai.Option
+	opts = append(opts, openai.WithBaseURL(config.ProviderURL))
+	opts = append(opts, openai.WithAPIKey(apiKey))
+	opts = append(opts, openai.WithName("custom"))
+	opts = append(opts, openai.WithLanguageModelOptions(
+		openai.WithLanguageModelExtraContentFunc(customExtraContentFunc),
+		openai.WithLanguageModelStreamExtraFunc(customStreamExtraFunc),
+		openai.WithLanguageModelToPromptFunc(customToPromptFunc),
+	))
 
 	if config.TLSSkipVerify {
-		opts = append(opts, openaicompat.WithHTTPClient(createHTTPClientWithTLSConfig(true)))
+		opts = append(opts, openai.WithHTTPClient(createHTTPClientWithTLSConfig(true)))
 	}
 
-	p, err := openaicompat.New(opts...)
+	p, err := openai.New(opts...)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create custom provider: %w", err)
 	}

internal/models/registry.go

@@ -17,6 +17,7 @@ var embeddedModelsJSON []byte
 type ModelInfo struct {
 	ID          string
 	Name        string
+	Family      string // Model family (e.g., "claude", "gpt", "gemini")
 	Attachment  bool
 	Reasoning   bool
 	Temperature bool
@@ -25,6 +26,44 @@ type ModelInfo struct {
 	ProviderNPM string // Model-specific provider npm override (e.g. "@ai-sdk/anthropic")
 }
 
+// SupportsCaching returns true if this model family supports prompt caching.
+// This enables automatic cost savings for supported models regardless of provider.
+func (m *ModelInfo) SupportsCaching() bool {
+	switch {
+	case strings.HasPrefix(m.Family, "claude"):
+		return true
+	case strings.HasPrefix(m.Family, "gpt"),
+		strings.HasPrefix(m.Family, "o1"),
+		strings.HasPrefix(m.Family, "o3"),
+		strings.HasPrefix(m.Family, "o4"),
+		strings.HasPrefix(m.Family, "codex"):
+		return true
+	case strings.HasPrefix(m.Family, "gemini"):
+		return true
+	default:
+		return false
+	}
+}
+
+// CacheType returns the appropriate cache mechanism for this model family.
+// Returns empty string if caching is not supported.
+func (m *ModelInfo) CacheType() string {
+	switch {
+	case strings.HasPrefix(m.Family, "claude"):
+		return "anthropic-ephemeral"
+	case strings.HasPrefix(m.Family, "gpt"),
+		strings.HasPrefix(m.Family, "o1"),
+		strings.HasPrefix(m.Family, "o3"),
+		strings.HasPrefix(m.Family, "o4"),
+		strings.HasPrefix(m.Family, "codex"):
+		return "openai-prompt-cache"
+	case strings.HasPrefix(m.Family, "gemini"):
+		return "google-cached-content"
+	default:
+		return ""
+	}
+}
+
 // Cost represents the pricing information for a model.
 type Cost struct {
 	Input      float64
@@ -86,6 +125,7 @@ func buildFromModelsDB() map[string]ProviderInfo {
 			modelsMap[modelID] = ModelInfo{
 				ID:          dm.ID,
 				Name:        dm.Name,
+				Family:      dm.Family,
 				Attachment:  dm.Attachment,
 				Reasoning:   dm.Reasoning,
 				Temperature: dm.Temperature,
@@ -308,27 +348,32 @@ func (r *ModelsRegistry) GetSupportedProviders() []string {
 	return providers
 }
 
-// GetFantasyProviders returns provider IDs that can be used with fantasy,
+// GetLLMProviders returns provider IDs that have LLM support,
 // either through a native provider or via openaicompat auto-routing.
-func (r *ModelsRegistry) GetFantasyProviders() []string {
+func (r *ModelsRegistry) GetLLMProviders() []string {
 	var providers []string
 	for providerID, info := range r.providers {
-		if isProviderFantasySupported(providerID, &info) {
+		if isProviderLLMSupported(providerID, &info) {
 			providers = append(providers, providerID)
 		}
 	}
 	return providers
 }
 
-// isProviderFantasySupported checks if a provider can be used with fantasy.
-func isProviderFantasySupported(providerID string, info *ProviderInfo) bool {
+// Deprecated: Use GetLLMProviders instead.
+func (r *ModelsRegistry) GetFantasyProviders() []string {
+	return r.GetLLMProviders()
+}
+
+// isProviderLLMSupported checks if a provider can be used with the LLM layer.
+func isProviderLLMSupported(providerID string, info *ProviderInfo) bool {
 	// Ollama is always supported (via openaicompat pointed at localhost)
 	if providerID == "ollama" {
 		return true
 	}
 
-	// Check if npm maps to a fantasy provider
-	if _, ok := npmToFantasyProvider[info.NPM]; ok {
+	// Check if npm maps to an LLM provider
+	if _, ok := npmToLLMProvider[info.NPM]; ok {
 		return true
 	}
 
@@ -355,6 +400,52 @@ func (r *ModelsRegistry) GetProviderInfo(provider string) *ProviderInfo {
 	return &info
 }
 
+// ValidateModelString checks whether a model string is well-formed and refers
+// to a known provider. It returns a user-friendly error with suggestions when
+// the model or provider is unrecognised. Passing validation does not guarantee
+// that API authentication will succeed — it only catches obvious mistakes
+// (typos, missing provider prefix, non-existent provider names) early so that
+// callers such as subagent spawning can return fast feedback.
+//
+// Unknown models under a known provider are allowed (the provider API is the
+// authority), but a completely unknown provider is rejected.
+func (r *ModelsRegistry) ValidateModelString(modelString string) error {
+	provider, modelName, err := ParseModelString(modelString)
+	if err != nil {
+		return err
+	}
+
+	// Ollama and custom are always valid — model names are user-defined.
+	if provider == "ollama" || provider == "custom" {
+		return nil
+	}
+
+	// Check if the provider exists in the registry.
+	providerInfo := r.GetProviderInfo(provider)
+	if providerInfo == nil {
+		known := r.GetSupportedProviders()
+		return fmt.Errorf(
+			"unknown provider %q in model string %q. Known providers: %s",
+			provider, modelString, strings.Join(known, ", "),
+		)
+	}
+
+	// Provider exists — check if the model is known. An unknown model is
+	// only a warning (the provider API decides), but we surface suggestions
+	// so the caller can self-correct.
+	if r.LookupModel(provider, modelName) == nil {
+		if suggestions := r.SuggestModels(provider, modelName); len(suggestions) > 0 {
+			return fmt.Errorf(
+				"model %q not found for provider %s. Did you mean one of: %s",
+				modelName, provider, strings.Join(suggestions, ", "),
+			)
+		}
+		// No suggestions — let it through; the provider API is the authority.
+	}
+
+	return nil
+}
+
 // Global registry instance
 var globalRegistry = NewModelsRegistry()
 

internal/models/registry_test.go

@@ -0,0 +1,92 @@
+package models
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestValidateModelString(t *testing.T) {
+	registry := GetGlobalRegistry()
+
+	tests := []struct {
+		name      string
+		model     string
+		wantErr   bool
+		errSubstr string // expected substring in error message (empty = don't check)
+	}{
+		{
+			name:    "valid anthropic model",
+			model:   "anthropic/claude-sonnet-4-6",
+			wantErr: false,
+		},
+		{
+			name:      "missing provider prefix",
+			model:     "claude-sonnet-4-6",
+			wantErr:   true,
+			errSubstr: "invalid model format",
+		},
+		{
+			name:      "empty string",
+			model:     "",
+			wantErr:   true,
+			errSubstr: "invalid model format",
+		},
+		{
+			name:      "unknown provider",
+			model:     "fakeprovider/some-model",
+			wantErr:   true,
+			errSubstr: "unknown provider",
+		},
+		{
+			name:    "ollama always valid",
+			model:   "ollama/llama3",
+			wantErr: false,
+		},
+		{
+			name:    "custom always valid",
+			model:   "custom/my-fine-tune",
+			wantErr: false,
+		},
+		{
+			name:      "empty provider",
+			model:     "/claude-sonnet-4-6",
+			wantErr:   true,
+			errSubstr: "invalid model format",
+		},
+		{
+			name:      "empty model name",
+			model:     "anthropic/",
+			wantErr:   true,
+			errSubstr: "invalid model format",
+		},
+		{
+			name:    "unknown model under known provider (no suggestions)",
+			model:   "anthropic/totally-unknown-xyz-999",
+			wantErr: false, // no suggestions → passes through
+		},
+		{
+			name:      "typo model under known provider with suggestions",
+			model:     "anthropic/claude-sonet", // misspelled "sonnet"
+			wantErr:   true,
+			errSubstr: "Did you mean",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := registry.ValidateModelString(tt.model)
+			if tt.wantErr && err == nil {
+				t.Errorf("ValidateModelString(%q) = nil, want error", tt.model)
+			}
+			if !tt.wantErr && err != nil {
+				t.Errorf("ValidateModelString(%q) = %v, want nil", tt.model, err)
+			}
+			if tt.errSubstr != "" && err != nil {
+				if !strings.Contains(err.Error(), tt.errSubstr) {
+					t.Errorf("ValidateModelString(%q) error = %q, want substring %q",
+						tt.model, err.Error(), tt.errSubstr)
+				}
+			}
+		})
+	}
+}

internal/session/tree_manager.go

@@ -114,6 +114,187 @@ func CreateTreeSession(cwd string) (*TreeManager, error) {
 	return tm, nil
 }
 
+// ForkToNewSession creates a new session file containing the history up to and
+// including the target entry ID. This matches Pi's /fork behavior: it creates
+// a completely new session file with a parent_session reference, copying all
+// entries from the root to the target point.
+func (tm *TreeManager) ForkToNewSession(cwd string, targetID string) (*TreeManager, error) {
+	tm.mu.RLock()
+	defer tm.mu.RUnlock()
+
+	// Get the branch from root to target (root-to-leaf order).
+	branch := tm.getBranchLocked(targetID)
+	if len(branch) == 0 {
+		return nil, fmt.Errorf("target entry %q not found", targetID)
+	}
+
+	// Create a new session file.
+	newTm, err := CreateTreeSession(cwd)
+	if err != nil {
+		return nil, err
+	}
+
+	// Set the parent session reference in the header.
+	newTm.header.ParentSession = tm.filePath
+	newTm.header.ParentSessionID = tm.header.ID
+
+	// Rewrite the header with the parent reference.
+	// We need to close and recreate the file to rewrite the header.
+	if err := newTm.file.Close(); err != nil {
+		return nil, fmt.Errorf("failed to close new session file: %w", err)
+	}
+
+	// Recreate the file and write the updated header.
+	f, err := os.Create(newTm.filePath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to recreate session file: %w", err)
+	}
+	newTm.file = f
+
+	if err := newTm.writeEntry(&newTm.header); err != nil {
+		_ = f.Close()
+		return nil, fmt.Errorf("failed to write session header: %w", err)
+	}
+
+	// Copy entries from the branch to the new session.
+	// We need to remap IDs since the new session is independent.
+	idMap := make(map[string]string) // old ID -> new ID
+	var prevNewID string
+
+	for _, entry := range branch {
+		oldID := tm.EntryID(entry)
+		newID := GenerateEntryID()
+		idMap[oldID] = newID
+
+		// Create a copy of the entry with the new ID and remapped parent.
+		var newEntry any
+		switch e := entry.(type) {
+		case *MessageEntry:
+			newEntry = &MessageEntry{
+				Entry: Entry{
+					Type:      EntryTypeMessage,
+					ID:        newID,
+					ParentID:  prevNewID, // Chain sequentially in new session
+					Timestamp: e.Timestamp,
+				},
+				Role:     e.Role,
+				Parts:    e.Parts,
+				Model:    e.Model,
+				Provider: e.Provider,
+			}
+			// Copy label if present.
+			if label, ok := tm.labels[oldID]; ok {
+				newTm.labels[newID] = label
+			}
+
+		case *ModelChangeEntry:
+			newEntry = &ModelChangeEntry{
+				Entry: Entry{
+					Type:      EntryTypeModelChange,
+					ID:        newID,
+					ParentID:  prevNewID,
+					Timestamp: e.Timestamp,
+				},
+				Provider: e.Provider,
+				ModelID:  e.ModelID,
+			}
+
+		case *LabelEntry:
+			// Remap the target ID if it's in our copied branch.
+			newTargetID := e.TargetID
+			if mapped, ok := idMap[e.TargetID]; ok {
+				newTargetID = mapped
+			}
+			newEntry = &LabelEntry{
+				Entry: Entry{
+					Type:      EntryTypeLabel,
+					ID:        newID,
+					ParentID:  prevNewID,
+					Timestamp: e.Timestamp,
+				},
+				TargetID: newTargetID,
+				Label:    e.Label,
+			}
+
+		case *SessionInfoEntry:
+			newEntry = &SessionInfoEntry{
+				Entry: Entry{
+					Type:      EntryTypeSessionInfo,
+					ID:        newID,
+					ParentID:  prevNewID,
+					Timestamp: e.Timestamp,
+				},
+				Name: e.Name,
+			}
+			newTm.sessionName = e.Name
+
+		case *ExtensionDataEntry:
+			newEntry = &ExtensionDataEntry{
+				Entry: Entry{
+					Type:      EntryTypeExtensionData,
+					ID:        newID,
+					ParentID:  prevNewID,
+					Timestamp: e.Timestamp,
+				},
+				ExtType: e.ExtType,
+				Data:    e.Data,
+			}
+
+		case *BranchSummaryEntry:
+			// Remap the from ID if it's in our copied branch.
+			newFromID := e.FromID
+			if mapped, ok := idMap[e.FromID]; ok {
+				newFromID = mapped
+			}
+			newEntry = &BranchSummaryEntry{
+				Entry: Entry{
+					Type:      EntryTypeBranchSummary,
+					ID:        newID,
+					ParentID:  prevNewID,
+					Timestamp: e.Timestamp,
+				},
+				FromID:  newFromID,
+				Summary: e.Summary,
+			}
+
+		case *CompactionEntry:
+			// Remap the first kept entry ID if it's in our copied branch.
+			newFirstKeptID := e.FirstKeptEntryID
+			if mapped, ok := idMap[e.FirstKeptEntryID]; ok {
+				newFirstKeptID = mapped
+			}
+			newEntry = &CompactionEntry{
+				Entry: Entry{
+					Type:      EntryTypeCompaction,
+					ID:        newID,
+					ParentID:  prevNewID,
+					Timestamp: e.Timestamp,
+				},
+				Summary:          e.Summary,
+				FirstKeptEntryID: newFirstKeptID,
+				TokensBefore:     e.TokensBefore,
+				TokensAfter:      e.TokensAfter,
+				MessagesRemoved:  e.MessagesRemoved,
+				ReadFiles:        e.ReadFiles,
+				ModifiedFiles:    e.ModifiedFiles,
+			}
+		}
+
+		if newEntry != nil {
+			if err := newTm.appendAndPersist(newEntry); err != nil {
+				_ = f.Close()
+				return nil, fmt.Errorf("failed to copy entry: %w", err)
+			}
+			prevNewID = newID
+		}
+	}
+
+	// Set the leaf to the last entry in the new session.
+	newTm.leafID = prevNewID
+
+	return newTm, nil
+}
+
 // OpenTreeSession opens an existing JSONL session file.
 func OpenTreeSession(path string) (*TreeManager, error) {
 	data, err := os.ReadFile(path)
@@ -181,7 +362,7 @@ func OpenTreeSession(path string) (*TreeManager, error) {
 
 	// Set leaf to the last entry.
 	if len(tm.entries) > 0 {
-		tm.leafID = tm.entryID(tm.entries[len(tm.entries)-1])
+		tm.leafID = tm.EntryID(tm.entries[len(tm.entries)-1])
 	}
 
 	// Open file for appending.
@@ -242,9 +423,14 @@ func (tm *TreeManager) AppendMessage(msg message.Message) (string, error) {
 	return entry.ID, nil
 }
 
-// AppendFantasyMessage converts a fantasy.Message and appends it.
+// AppendLLMMessage converts an LLM message and appends it.
+func (tm *TreeManager) AppendLLMMessage(msg fantasy.Message) (string, error) {
+	return tm.AppendMessage(message.FromLLMMessage(msg))
+}
+
+// Deprecated: Use AppendLLMMessage instead.
 func (tm *TreeManager) AppendFantasyMessage(msg fantasy.Message) (string, error) {
-	return tm.AppendMessage(message.FromFantasyMessage(msg))
+	return tm.AppendLLMMessage(msg)
 }
 
 // AppendModelChange records a model/provider change.
@@ -521,7 +707,7 @@ func (tm *TreeManager) BuildContext() (messages []fantasy.Message, provider stri
 	for _, entry := range branch {
 		// Once we reach the first kept entry, stop skipping.
 		if skipping {
-			entryID := tm.entryID(entry)
+			entryID := tm.EntryID(entry)
 			if entryID == lastCompaction.FirstKeptEntryID {
 				skipping = false
 			} else {
@@ -535,7 +721,7 @@ func (tm *TreeManager) BuildContext() (messages []fantasy.Message, provider stri
 			if err != nil {
 				continue // skip malformed entries
 			}
-			msgs := msg.ToFantasyMessages()
+			msgs := msg.ToLLMMessages()
 			messages = append(messages, msgs...)
 
 		case *BranchSummaryEntry:
@@ -684,7 +870,7 @@ func (tm *TreeManager) GetContextEntryIDs() []string {
 	skipping := lastCompaction != nil
 	for _, entry := range branch {
 		if skipping {
-			entryID := tm.entryID(entry)
+			entryID := tm.EntryID(entry)
 			if entryID == lastCompaction.FirstKeptEntryID {
 				skipping = false
 			} else {
@@ -698,7 +884,7 @@ func (tm *TreeManager) GetContextEntryIDs() []string {
 			if err != nil {
 				continue
 			}
-			msgs := msg.ToFantasyMessages()
+			msgs := msg.ToLLMMessages()
 			for range msgs {
 				ids = append(ids, e.ID)
 			}
@@ -737,31 +923,41 @@ func (tm *TreeManager) GetLastCompaction() *CompactionEntry {
 
 // --- Legacy bridge ---
 
-// AddFantasyMessages appends multiple fantasy messages as entries. This is
+// AddLLMMessages appends multiple LLM messages as entries. This is
 // used when syncing from the agent's ConversationMessages after a step.
-func (tm *TreeManager) AddFantasyMessages(msgs []fantasy.Message) error {
+func (tm *TreeManager) AddLLMMessages(msgs []fantasy.Message) error {
 	for _, msg := range msgs {
-		if _, err := tm.AppendFantasyMessage(msg); err != nil {
+		if _, err := tm.AppendLLMMessage(msg); err != nil {
 			return err
 		}
 	}
 	return nil
 }
 
-// GetFantasyMessages builds the context and returns just the messages.
+// Deprecated: Use AddLLMMessages instead.
+func (tm *TreeManager) AddFantasyMessages(msgs []fantasy.Message) error {
+	return tm.AddLLMMessages(msgs)
+}
+
+// GetLLMMessages builds the context and returns just the messages.
 // This satisfies the same conceptual role as the old Manager.GetMessages().
-func (tm *TreeManager) GetFantasyMessages() []fantasy.Message {
+func (tm *TreeManager) GetLLMMessages() []fantasy.Message {
 	msgs, _, _ := tm.BuildContext()
 	return msgs
 }
 
+// Deprecated: Use GetLLMMessages instead.
+func (tm *TreeManager) GetFantasyMessages() []fantasy.Message {
+	return tm.GetLLMMessages()
+}
+
 // --- Internal helpers ---
 
 // addEntryToIndex adds an entry to the in-memory indices.
 func (tm *TreeManager) addEntryToIndex(entry any) {
 	tm.entries = append(tm.entries, entry)
 
-	id := tm.entryID(entry)
+	id := tm.EntryID(entry)
 	parentID := tm.entryParentID(entry)
 
 	if id != "" {
@@ -798,8 +994,8 @@ func (tm *TreeManager) writeEntry(entry any) error {
 	return err
 }
 
-// entryID extracts the ID from any entry type.
-func (tm *TreeManager) entryID(entry any) string {
+// EntryID extracts the ID from any entry type.
+func (tm *TreeManager) EntryID(entry any) string {
 	switch e := entry.(type) {
 	case *MessageEntry:
 		return e.ID

internal/tools/connection_pool.go

@@ -127,9 +127,7 @@ func (p *MCPConnectionPool) GetConnection(ctx context.Context, serverName string
 			return conn, nil
 		} else {
 			if p.debugLogger != nil && p.debugLogger.IsDebugEnabled() {
-				if p.debugLogger != nil && p.debugLogger.IsDebugEnabled() {
-					p.debugLogger.LogDebug(fmt.Sprintf("[POOL] Connection %s unhealthy, removing", serverName))
-				}
+				p.debugLogger.LogDebug(fmt.Sprintf("[POOL] Connection %s unhealthy, removing", serverName))
 			}
 			_ = conn.client.Close()
 			delete(p.connections, serverName)

internal/tools/mcp_test.go

@@ -3,6 +3,7 @@ package tools
 import (
 	"context"
 	"encoding/json"
+	"strings"
 	"testing"
 	"time"
 
@@ -70,7 +71,7 @@ func TestMCPToolManager_LoadTools_GracefulFailure(t *testing.T) {
 	}
 
 	// The error should mention that all servers failed
-	if err != nil && !contains(err.Error(), "all MCP servers failed") {
+	if err != nil && !strings.Contains(err.Error(), "all MCP servers failed") {
 		t.Errorf("Expected error message to mention all servers failed, got: %v", err)
 	}
 
@@ -459,13 +460,3 @@ func sliceEqual(a, b []any) bool {
 	}
 	return true
 }
-
-// Helper function to check if a string contains a substring
-func contains(s, substr string) bool {
-	for i := 0; i <= len(s)-len(substr); i++ {
-		if s[i:i+len(substr)] == substr {
-			return true
-		}
-	}
-	return false
-}

internal/ui/block_renderer.go

@@ -4,6 +4,8 @@ import (
 	"image/color"
 
 	"charm.land/lipgloss/v2"
+
+	"github.com/mark3labs/kit/internal/ui/style"
 )
 
 // blockRenderer handles rendering of content blocks with configurable options
@@ -175,7 +177,7 @@ func renderContentBlock(content string, containerWidth int, options ...rendering
 		borderChars = 1
 	}
 
-	theme := GetTheme()
+	theme := style.GetTheme()
 
 	// Resolve foreground color: caller override or theme default.
 	fgColor := theme.Text

internal/ui/children_test.go

@@ -6,6 +6,7 @@ import (
 
 	tea "charm.land/bubbletea/v2"
 	"github.com/mark3labs/kit/internal/app"
+	"github.com/mark3labs/kit/internal/ui/core"
 )
 
 // ==========================================================================
@@ -59,7 +60,7 @@ func TestInputComponent_SubmitEmitsSubmitMsg(t *testing.T) {
 		t.Fatal("expected a cmd from pressing enter on non-empty input")
 	}
 
-	sm, ok := msg.(submitMsg)
+	sm, ok := msg.(core.SubmitMsg)
 	if !ok {
 		t.Fatalf("expected submitMsg, got %T", msg)
 	}
@@ -83,7 +84,7 @@ func TestInputComponent_CtrlD_SubmitEmitsSubmitMsg(t *testing.T) {
 	if msg == nil {
 		t.Fatal("expected a cmd from ctrl+d on non-empty input")
 	}
-	sm, ok := msg.(submitMsg)
+	sm, ok := msg.(core.SubmitMsg)
 	if !ok {
 		t.Fatalf("expected submitMsg from ctrl+d, got %T", msg)
 	}
@@ -149,11 +150,13 @@ func TestInputComponent_QuitReturnsTeaQuit(t *testing.T) {
 }
 
 // --------------------------------------------------------------------------
-// TestInputComponent_ClearCallsClearMessages verifies that /clear (and its
-// aliases) calls appCtrl.ClearMessages() and returns no submitMsg.
+// TestInputComponent_ClearForwardsAsSubmitMsg verifies that /clear (and its
+// aliases) are forwarded as submitMsg to the parent model so that the parent
+// can call ClearMessages(), update scrollback, and print the confirmation
+// message in one place. InputComponent must NOT call ClearMessages() directly.
 // --------------------------------------------------------------------------
 
-func TestInputComponent_ClearCallsClearMessages(t *testing.T) {
+func TestInputComponent_ClearForwardsAsSubmitMsg(t *testing.T) {
 	aliases := []string{"/clear", "/c", "/cls"}
 	for _, alias := range aliases {
 		t.Run(alias, func(t *testing.T) {
@@ -164,22 +167,29 @@ func TestInputComponent_ClearCallsClearMessages(t *testing.T) {
 
 			_, cmd := sendInputMsg(c, tea.KeyPressMsg{Code: tea.KeyEnter})
 
-			if ctrl.clearMsgCalled != 1 {
-				t.Fatalf("%s: expected ClearMessages() called once, got %d", alias, ctrl.clearMsgCalled)
+			// InputComponent must NOT call ClearMessages() directly.
+			if ctrl.clearMsgCalled != 0 {
+				t.Fatalf("%s: InputComponent must not call ClearMessages(), got %d", alias, ctrl.clearMsgCalled)
 			}
-			// No cmd should be returned (no submitMsg forwarded to parent).
-			if cmd != nil {
-				msg := runCmd(cmd)
-				if _, ok := msg.(submitMsg); ok {
-					t.Fatalf("%s: /clear should not emit submitMsg, got submitMsg", alias)
-				}
+			// A submitMsg must be emitted so the parent model handles /clear.
+			if cmd == nil {
+				t.Fatalf("%s: expected submitMsg cmd, got nil", alias)
+			}
+			msg := runCmd(cmd)
+			sm, ok := msg.(core.SubmitMsg)
+			if !ok {
+				t.Fatalf("%s: expected submitMsg, got %T", alias, msg)
+			}
+			if sm.Text != alias {
+				t.Fatalf("%s: expected submitMsg text %q, got %q", alias, alias, sm.Text)
 			}
 		})
 	}
 }
 
 // TestInputComponent_ClearNilCtrl_NoPanic verifies that /clear with a nil
-// appCtrl does not panic.
+// appCtrl does not panic. Since /clear is now forwarded to the parent via
+// submitMsg, no appCtrl interaction happens in InputComponent at all.
 func TestInputComponent_ClearNilCtrl_NoPanic(t *testing.T) {
 	c := newTestInput(nil)
 	c.textarea.SetValue("/clear")
@@ -221,7 +231,7 @@ func TestInputComponent_ClearQueue_ForwardsAsSubmitMsg(t *testing.T) {
 				t.Fatalf("%s: expected submitMsg cmd, got nil", alias)
 			}
 			msg := runCmd(cmd)
-			sm, ok := msg.(submitMsg)
+			sm, ok := msg.(core.SubmitMsg)
 			if !ok {
 				t.Fatalf("%s: expected submitMsg, got %T", alias, msg)
 			}
@@ -249,7 +259,7 @@ func TestInputComponent_UnknownSlashCommand_ForwardsAsSubmit(t *testing.T) {
 	if msg == nil {
 		t.Fatal("expected submitMsg for unknown slash command")
 	}
-	sm, ok := msg.(submitMsg)
+	sm, ok := msg.(core.SubmitMsg)
 	if !ok {
 		t.Fatalf("expected submitMsg for unknown slash command, got %T", msg)
 	}
@@ -266,10 +276,9 @@ func TestInputComponent_UnknownSlashCommand_ForwardsAsSubmit(t *testing.T) {
 // Helpers
 // --------------------------------------------------------------------------
 
-// newTestStream creates a StreamComponent with a fixed width and model name,
-// in non-compact mode.
+// newTestStream creates a StreamComponent with a fixed width and model name.
 func newTestStream() *StreamComponent {
-	return NewStreamComponent(false, 80, "test-model")
+	return NewStreamComponent(80, "test-model")
 }
 
 // sendStreamMsg calls component.Update and returns the updated component.
@@ -690,3 +699,38 @@ func TestStreamComponent_StaleFlushTick_Discarded(t *testing.T) {
 		t.Fatalf("expected streamContent='new' after current flush, got %q", got)
 	}
 }
+
+// TestStreamComponent_ConsumeOverflow_NoHeight verifies that when height is
+// unconstrained (0), ConsumeOverflow always returns "".
+func TestStreamComponent_ConsumeOverflow_NoOp(t *testing.T) {
+	c := newTestStream()
+	// Commit some content directly.
+	c.streamContent.WriteString("line1\nline2\nline3")
+	c.phase = streamPhaseActive
+
+	// ConsumeOverflow is a no-op in alt screen mode — always returns "".
+	if got := c.ConsumeOverflow(); got != "" {
+		t.Fatalf("expected empty from no-op ConsumeOverflow, got %q", got)
+	}
+
+	// Also returns "" with a height set.
+	c.height = 2
+	if got := c.ConsumeOverflow(); got != "" {
+		t.Fatalf("expected empty from no-op ConsumeOverflow with height, got %q", got)
+	}
+}
+
+// TestStreamComponent_GetRenderedContent_ReturnsAll verifies that
+// GetRenderedContent returns all accumulated content.
+func TestStreamComponent_GetRenderedContent_ReturnsAll(t *testing.T) {
+	c := newTestStream()
+	c.renderer = nil
+	c.phase = streamPhaseActive
+
+	c.streamContent.WriteString("a\nb\nc\nd\ne")
+
+	got := c.GetRenderedContent()
+	if got != "a\nb\nc\nd\ne" {
+		t.Fatalf("expected full content, got %q", got)
+	}
+}

internal/ui/cli.go

@@ -8,36 +8,31 @@ import (
 	"charm.land/fantasy"
 	"charm.land/lipgloss/v2"
 	"golang.org/x/term"
+
+	"github.com/mark3labs/kit/internal/ui/style"
 )
 
 // CLI manages the command-line interface for KIT, providing message rendering,
-// user input handling, and display management. It supports both standard and compact
-// display modes, handles streaming responses, tracks token usage, and manages the
-// overall conversation flow between the user and AI assistants.
+// user input handling, and display management. It handles streaming responses,
+// tracks token usage, and manages the overall conversation flow between the
+// user and AI assistants.
 type CLI struct {
 	renderer     Renderer
 	usageTracker *UsageTracker
 	width        int
-	compactMode  bool
 	debug        bool
 	modelName    string
 }
 
-// NewCLI creates and initializes a new CLI instance with the specified display modes.
-// The debug parameter enables debug message rendering, while compact enables a more
-// condensed display format. Returns an initialized CLI ready for interaction or an
+// NewCLI creates and initializes a new CLI instance. The debug parameter enables
+// debug message rendering. Returns an initialized CLI ready for interaction or an
 // error if initialization fails.
-func NewCLI(debug bool, compact bool) (*CLI, error) {
+func NewCLI(debug bool) (*CLI, error) {
 	cli := &CLI{
-		compactMode: compact,
-		debug:       debug,
+		debug: debug,
 	}
 	cli.updateSize()
-	if compact {
-		cli.renderer = NewCompactRenderer(cli.width, debug)
-	} else {
-		cli.renderer = newMessageRenderer(cli.width, debug)
-	}
+	cli.renderer = newMessageRenderer(cli.width, debug)
 
 	return cli, nil
 }
@@ -132,7 +127,7 @@ func (c *CLI) DisplayInfo(message string) {
 // DisplayExtensionBlock renders a custom styled block with the given border
 // color and optional subtitle. Used by extensions via ctx.PrintBlock.
 func (c *CLI) DisplayExtensionBlock(text, borderColor, subtitle string) {
-	theme := GetTheme()
+	theme := style.GetTheme()
 
 	borderClr := theme.Info
 	if borderColor != "" {

internal/ui/clipboard/clipboard.go

@@ -0,0 +1,26 @@
+package clipboard
+
+import (
+	tea "charm.land/bubbletea/v2"
+	"github.com/atotto/clipboard"
+)
+
+// CopyToClipboard writes text to both the system clipboard and via OSC 52.
+// Returns a tea.Cmd that can be used in Bubble Tea's Update flow.
+func CopyToClipboard(text string) tea.Cmd {
+	if text == "" {
+		return nil
+	}
+
+	return tea.Sequence(
+		// Method 1: OSC 52 escape sequence (works in modern terminals)
+		tea.SetClipboard(text),
+
+		// Method 2: Native system clipboard (atotto/clipboard)
+		func() tea.Msg {
+			// Best effort - ignore errors
+			_ = clipboard.WriteAll(text)
+			return nil
+		},
+	)
+}

internal/ui/commands/commands.go

@@ -1,4 +1,4 @@
-package ui
+package commands
 
 import (
 	"slices"
@@ -7,6 +7,10 @@ import (
 	"github.com/mark3labs/kit/internal/models"
 )
 
+// ListThemesFunc is set by the ui package to provide theme name completion.
+// This breaks the circular dependency between commands and ui packages.
+var ListThemesFunc func() []string
+
 // SlashCommand represents a user-invokable slash command with its metadata.
 // Commands can have multiple aliases and are organized by category for better
 // discoverability and help display.
@@ -99,7 +103,10 @@ var SlashCommands = []SlashCommand{
 		Description: "Switch color theme (e.g. /theme catppuccin)",
 		Category:    "System",
 		Complete: func(prefix string) []string {
-			names := ListThemes()
+			if ListThemesFunc == nil {
+				return nil
+			}
+			names := ListThemesFunc()
 			if prefix == "" {
 				return names
 			}
@@ -112,6 +119,12 @@ var SlashCommands = []SlashCommand{
 			return matches
 		},
 	},
+	{
+		Name:        "/reload-ext",
+		Description: "Hot-reload all extensions from disk",
+		Category:    "System",
+		Aliases:     []string{"/re"},
+	},
 	{
 		Name:        "/quit",
 		Description: "Exit the application",
@@ -127,7 +140,7 @@ var SlashCommands = []SlashCommand{
 	},
 	{
 		Name:        "/fork",
-		Description: "Branch from an earlier message",
+		Description: "Fork to new session from an earlier message",
 		Category:    "Navigation",
 	},
 	{

internal/ui/compact_renderer.go

@@ -1,494 +0,0 @@
-package ui
-
-import (
-	"fmt"
-	"strings"
-	"time"
-
-	"charm.land/lipgloss/v2"
-)
-
-// CompactRenderer handles rendering messages in a space-efficient compact format,
-// optimized for terminals with limited vertical space. It displays messages with
-// minimal decorations while maintaining readability and essential information.
-type CompactRenderer struct {
-	width int
-	debug bool
-
-	// getToolRenderer returns extension-provided rendering overrides for a
-	// specific tool. May be nil if no extensions are loaded. Used in
-	// RenderToolMessage to check for custom header/body formatting before
-	// falling back to builtin renderers.
-	getToolRenderer func(toolName string) *ToolRendererData
-}
-
-// NewCompactRenderer creates and initializes a new CompactRenderer with the specified
-// terminal width and debug mode setting. The width parameter determines line wrapping,
-// while debug enables additional diagnostic output in rendered messages.
-func NewCompactRenderer(width int, debug bool) *CompactRenderer {
-	return &CompactRenderer{
-		width: width,
-		debug: debug,
-	}
-}
-
-// SetWidth updates the terminal width for the renderer, affecting how content
-// is wrapped and formatted in subsequent render operations.
-func (r *CompactRenderer) SetWidth(width int) {
-	r.width = width
-}
-
-// RenderUserMessage renders a user's input message in compact format with a
-// distinctive symbol (>) and label. The content is formatted to preserve structure
-// while minimizing vertical space usage. Returns a UIMessage with formatted content
-// and metadata.
-func (r *CompactRenderer) RenderUserMessage(content string, timestamp time.Time) UIMessage {
-	theme := getTheme()
-	symbol := lipgloss.NewStyle().Foreground(theme.Info).Render(">")
-	label := lipgloss.NewStyle().Foreground(theme.Info).Bold(true).Render("User")
-
-	// Only run markdown rendering when the message contains code spans or
-	// fenced code blocks. Plain text is rendered directly so that newlines
-	// are preserved without the extra paragraph spacing glamour adds.
-	var compactContent string
-	if strings.Contains(content, "`") {
-		mdContent := strings.ReplaceAll(content, "\n", "\n\n")
-		compactContent = r.formatUserAssistantContent(mdContent)
-		compactContent = removeBlankLines(compactContent)
-	} else {
-		compactContent = content
-	}
-
-	// Handle multi-line content
-	lines := strings.Split(compactContent, "\n")
-	var formattedLines []string
-
-	for i, line := range lines {
-		if i == 0 {
-			// First line includes symbol and label
-			formattedLines = append(formattedLines, fmt.Sprintf("%s  %s %s", symbol, label, line))
-		} else {
-			// Subsequent lines without indentation for compact mode
-			formattedLines = append(formattedLines, line)
-		}
-	}
-
-	return UIMessage{
-		Type:      UserMessage,
-		Content:   strings.Join(formattedLines, "\n"),
-		Height:    len(formattedLines),
-		Timestamp: timestamp,
-	}
-}
-
-// RenderAssistantMessage renders an AI assistant's response in compact format with
-// a distinctive symbol (<) and the model name as label. Empty content is ignored
-// and returns an empty message. Returns a UIMessage with formatted content and metadata.
-func (r *CompactRenderer) RenderAssistantMessage(content string, timestamp time.Time, modelName string) UIMessage {
-	// Ignore empty responses - don't render anything
-	compactContent := r.formatUserAssistantContent(content)
-	if compactContent == "" {
-		return UIMessage{
-			Type:      AssistantMessage,
-			Content:   "",
-			Height:    0,
-			Timestamp: timestamp,
-		}
-	}
-
-	theme := getTheme()
-	symbol := lipgloss.NewStyle().Foreground(theme.Primary).Render("<")
-
-	// Use the full model name, fallback to "Assistant" if empty
-	if modelName == "" {
-		modelName = "Assistant"
-	}
-	label := lipgloss.NewStyle().Foreground(theme.Primary).Bold(true).Render(modelName)
-
-	// Handle multi-line content
-	lines := strings.Split(compactContent, "\n")
-	var formattedLines []string
-
-	for i, line := range lines {
-		if i == 0 {
-			// First line includes symbol and label
-			formattedLines = append(formattedLines, fmt.Sprintf("%s  %s %s", symbol, label, line))
-		} else {
-			// Subsequent lines without indentation for compact mode
-			formattedLines = append(formattedLines, line)
-		}
-	}
-
-	return UIMessage{
-		Type:      AssistantMessage,
-		Content:   strings.Join(formattedLines, "\n"),
-		Height:    len(formattedLines),
-		Timestamp: timestamp,
-	}
-}
-
-// RenderToolCallMessage renders a tool call notification in compact format, showing
-// the tool being executed with its arguments in a single line. The tool name is
-// highlighted and arguments are displayed in a muted color for visual distinction.
-func (r *CompactRenderer) RenderToolCallMessage(toolName, toolArgs string, timestamp time.Time) UIMessage {
-	theme := getTheme()
-	symbol := lipgloss.NewStyle().Foreground(theme.Tool).Render("[")
-	label := lipgloss.NewStyle().Foreground(theme.Tool).Bold(true).Render(toolName)
-
-	// Format args for compact display
-	argsDisplay := r.formatToolArgs(toolArgs)
-	if argsDisplay != "" {
-		argsDisplay = lipgloss.NewStyle().Foreground(theme.Muted).Render(argsDisplay)
-	}
-
-	line := fmt.Sprintf("%s  %s %s", symbol, label, argsDisplay)
-
-	return UIMessage{
-		Type:      ToolCallMessage,
-		Content:   line,
-		Height:    1,
-		Timestamp: timestamp,
-	}
-}
-
-// RenderToolMessage renders a unified tool block in compact format, combining
-// the tool invocation header (icon + display name + params) with the execution
-// result body. Status is indicated by icon: checkmark for success, cross for error.
-func (r *CompactRenderer) RenderToolMessage(toolName, toolArgs, toolResult string, isError bool) UIMessage {
-	theme := getTheme()
-
-	// Resolve extension renderer once for all overrides.
-	var extRd *ToolRendererData
-	if r.getToolRenderer != nil {
-		extRd = r.getToolRenderer(toolName)
-	}
-
-	// Status icon
-	var icon string
-	iconColor := theme.Success
-	if isError {
-		icon = "×"
-		iconColor = theme.Error
-	} else {
-		icon = "✓"
-	}
-
-	iconStr := lipgloss.NewStyle().Foreground(iconColor).Bold(true).Render(icon)
-
-	// Extension can override display name.
-	displayName := toolDisplayName(toolName)
-	if extRd != nil && extRd.DisplayName != "" {
-		displayName = extRd.DisplayName
-	}
-	nameStr := lipgloss.NewStyle().Foreground(theme.Info).Bold(true).Render(displayName)
-
-	// Format params — check extension renderer first.
-	paramBudget := max(r.width-10-len(displayName), 20)
-	var params string
-	if extRd != nil && extRd.RenderHeader != nil {
-		params = extRd.RenderHeader(toolArgs, paramBudget)
-	}
-	if params == "" {
-		params = formatToolParams(toolArgs, paramBudget)
-	}
-
-	// Build header line
-	header := iconStr + " " + nameStr
-	if params != "" {
-		header += " " + lipgloss.NewStyle().Foreground(theme.Muted).Render(params)
-	}
-
-	// Format body: check extension renderer first, then compact builtin, then default.
-	var body string
-	if extRd != nil && extRd.RenderBody != nil {
-		body = extRd.RenderBody(toolResult, isError, r.width-4)
-		// Apply markdown rendering if requested and body is non-empty.
-		if body != "" && extRd.BodyMarkdown {
-			body = strings.TrimSuffix(toMarkdown(body, r.width-4), "\n")
-		}
-	}
-	if body == "" {
-		if isError {
-			body = lipgloss.NewStyle().Foreground(theme.Error).Render(r.formatToolResult(toolResult))
-		} else {
-			// Use compact summary renderers instead of full tool body renderers.
-			body = renderToolBodyCompact(toolName, toolArgs, toolResult, r.width-4)
-			if body == "" {
-				formatted := r.formatToolResult(toolResult)
-				if formatted == "" {
-					body = lipgloss.NewStyle().Foreground(theme.Muted).Italic(true).Render("(no output)")
-				} else {
-					body = lipgloss.NewStyle().Foreground(theme.Muted).Render(formatted)
-				}
-			}
-		}
-	}
-
-	// Combine header + indented body
-	var lines []string
-	lines = append(lines, header)
-	if body != "" {
-		for line := range strings.SplitSeq(body, "\n") {
-			lines = append(lines, "  "+line)
-		}
-	}
-
-	return UIMessage{
-		Type:    ToolMessage,
-		Content: strings.Join(lines, "\n"),
-		Height:  len(lines),
-	}
-}
-
-// RenderSystemMessage renders a system notification or informational message in
-// compact format with a distinctive symbol (*) and "System" label. Content is
-// formatted to fit on a single line for minimal space usage.
-func (r *CompactRenderer) RenderSystemMessage(content string, timestamp time.Time) UIMessage {
-	theme := getTheme()
-	symbol := lipgloss.NewStyle().Foreground(theme.Muted).Render("◇")
-	label := lipgloss.NewStyle().Foreground(theme.Muted).Bold(true).Render("System")
-
-	compactContent := r.formatCompactContent(content)
-
-	line := fmt.Sprintf("%s  %-8s %s", symbol, label, compactContent)
-
-	return UIMessage{
-		Type:      SystemMessage,
-		Content:   line,
-		Height:    1,
-		Timestamp: timestamp,
-	}
-}
-
-// RenderErrorMessage renders an error notification in compact format with a
-// distinctive error symbol (!) and styling to ensure visibility. The error
-// content is displayed in a single line with appropriate color highlighting.
-func (r *CompactRenderer) RenderErrorMessage(errorMsg string, timestamp time.Time) UIMessage {
-	theme := getTheme()
-	symbol := lipgloss.NewStyle().Foreground(theme.Error).Render("!")
-	label := lipgloss.NewStyle().Foreground(theme.Error).Bold(true).Render("Error")
-
-	compactContent := lipgloss.NewStyle().Foreground(theme.Error).Render(r.formatCompactContent(errorMsg))
-
-	line := fmt.Sprintf("%s  %-8s %s", symbol, label, compactContent)
-
-	return UIMessage{
-		Type:      ErrorMessage,
-		Content:   line,
-		Height:    1,
-		Timestamp: timestamp,
-	}
-}
-
-// RenderDebugMessage renders diagnostic information in compact format when debug
-// mode is enabled. Messages are truncated if they exceed the available width to
-// maintain single-line display.
-func (r *CompactRenderer) RenderDebugMessage(message string, timestamp time.Time) UIMessage {
-	theme := getTheme()
-	symbol := lipgloss.NewStyle().Foreground(theme.Tool).Render("*")
-	label := lipgloss.NewStyle().Foreground(theme.Tool).Bold(true).Render("Debug")
-
-	// Truncate message if too long
-	content := message
-	if len(content) > r.width-20 {
-		content = content[:r.width-23] + "..."
-	}
-
-	line := fmt.Sprintf("%s  %-8s %s", symbol, label, content)
-
-	return UIMessage{
-		Type:      SystemMessage,
-		Content:   line,
-		Height:    1,
-		Timestamp: timestamp,
-	}
-}
-
-// RenderDebugConfigMessage renders configuration settings in compact format for
-// debugging purposes. Config entries are displayed as key=value pairs separated
-// by commas, truncated if necessary to fit on a single line.
-func (r *CompactRenderer) RenderDebugConfigMessage(config map[string]any, timestamp time.Time) UIMessage {
-	theme := getTheme()
-	symbol := lipgloss.NewStyle().Foreground(theme.Tool).Render("*")
-	label := lipgloss.NewStyle().Foreground(theme.Tool).Bold(true).Render("Debug")
-
-	// Format config as compact key=value pairs
-	var configPairs []string
-	for key, value := range config {
-		if value != nil {
-			configPairs = append(configPairs, fmt.Sprintf("%s=%v", key, value))
-		}
-	}
-
-	content := strings.Join(configPairs, ", ")
-	if len(content) > r.width-20 {
-		content = content[:r.width-23] + "..."
-	}
-
-	line := fmt.Sprintf("%s  %-8s %s", symbol, label, content)
-
-	return UIMessage{
-		Type:      SystemMessage,
-		Content:   line,
-		Height:    1,
-		Timestamp: timestamp,
-	}
-}
-
-// formatCompactContent formats content for compact single-line display
-func (r *CompactRenderer) formatCompactContent(content string) string {
-	if content == "" {
-		return ""
-	}
-
-	// Remove markdown formatting for compact display
-	content = strings.ReplaceAll(content, "\n", " ")
-	content = strings.ReplaceAll(content, "\t", " ")
-
-	// Collapse multiple spaces
-	for strings.Contains(content, "  ") {
-		content = strings.ReplaceAll(content, "  ", " ")
-	}
-
-	content = strings.TrimSpace(content)
-
-	// Truncate if too long (unless in debug mode)
-	maxLen := max(
-		// Reserve space for symbol and label more conservatively
-		r.width-28,
-		// Minimum width for readability
-		40)
-	if !r.debug && len(content) > maxLen {
-		content = content[:maxLen-3] + "..."
-	}
-
-	return content
-}
-
-// formatUserAssistantContent formats user and assistant content using glamour markdown rendering
-func (r *CompactRenderer) formatUserAssistantContent(content string) string {
-	if content == "" {
-		return ""
-	}
-
-	// Calculate available width more conservatively
-	// Account for: symbol (1) + spaces (2) + label (up to 20 chars) + space (1) + margin (4)
-	availableWidth := max(r.width-28,
-		// Minimum width for readability
-		40)
-
-	// Use glamour to render markdown content with proper width
-	rendered := toMarkdown(content, availableWidth)
-	return strings.TrimSuffix(rendered, "\n")
-}
-
-// wrapText wraps text to the specified width, preserving existing line breaks
-func (r *CompactRenderer) wrapText(text string, width int) string {
-	if width <= 0 {
-		return text
-	}
-
-	lines := strings.Split(text, "\n")
-	var wrappedLines []string
-
-	for _, line := range lines {
-		if len(line) <= width {
-			wrappedLines = append(wrappedLines, line)
-			continue
-		}
-
-		// Wrap long lines
-		words := strings.Fields(line)
-		if len(words) == 0 {
-			wrappedLines = append(wrappedLines, line)
-			continue
-		}
-
-		currentLine := ""
-		for _, word := range words {
-			// If adding this word would exceed the width, start a new line
-			if len(currentLine)+len(word)+1 > width && currentLine != "" {
-				wrappedLines = append(wrappedLines, currentLine)
-				currentLine = word
-			} else {
-				if currentLine == "" {
-					currentLine = word
-				} else {
-					currentLine += " " + word
-				}
-			}
-		}
-		if currentLine != "" {
-			wrappedLines = append(wrappedLines, currentLine)
-		}
-	}
-
-	return strings.Join(wrappedLines, "\n")
-}
-
-// formatToolArgs formats tool arguments for compact display
-func (r *CompactRenderer) formatToolArgs(args string) string {
-	if args == "" || args == "{}" {
-		return ""
-	}
-
-	// Remove JSON braces and format compactly
-	args = strings.TrimSpace(args)
-	if strings.HasPrefix(args, "{") && strings.HasSuffix(args, "}") {
-		args = strings.TrimPrefix(args, "{")
-		args = strings.TrimSuffix(args, "}")
-		args = strings.TrimSpace(args)
-	}
-
-	// Remove quotes around simple values
-	args = strings.ReplaceAll(args, `"`, "")
-
-	// Remove parameter names (e.g., "command: ls" -> "ls", "path: /home" -> "/home")
-	// Look for pattern "key: value" and extract just the value
-	if colonIndex := strings.Index(args, ":"); colonIndex != -1 {
-		args = strings.TrimSpace(args[colonIndex+1:])
-	}
-
-	return r.formatCompactContent(args)
-}
-
-// formatToolResult formats tool results preserving formatting but limiting to 5 lines
-func (r *CompactRenderer) formatToolResult(result string) string {
-	if result == "" {
-		return ""
-	}
-
-	// Check if this is bash output with stdout/stderr tags
-	if strings.Contains(result, "<stdout>") || strings.Contains(result, "<stderr>") {
-		result = r.formatBashOutput(result)
-	}
-
-	// Calculate available width more conservatively
-	availableWidth := max(r.width-28,
-		// Minimum width for readability
-		40)
-
-	// First wrap the text to prevent long lines (tool results are usually plain text, not markdown)
-	wrappedResult := r.wrapText(result, availableWidth)
-
-	// Then limit to 5 lines
-	lines := strings.Split(wrappedResult, "\n")
-	if len(lines) > 5 {
-		lines = lines[:5]
-		// Add truncation indicator
-		if len(lines) == 5 && lines[4] != "" {
-			lines[4] = lines[4] + "..."
-		} else {
-			lines = append(lines, "...")
-		}
-	}
-
-	return strings.Join(lines, "\n")
-}
-
-// formatBashOutput formats bash command output by removing stdout/stderr tags
-// and styling appropriately. Delegates tag parsing to the shared parseBashOutput
-// helper.
-func (r *CompactRenderer) formatBashOutput(result string) string {
-	return parseBashOutput(result, getTheme())
-}

internal/ui/core/events.go

@@ -1,4 +1,4 @@
-package ui
+package core
 
 // ImageAttachment holds a clipboard image that will be sent alongside the
 // user's text prompt to the LLM. The data is raw image bytes; MediaType is
@@ -10,9 +10,9 @@ type ImageAttachment struct {
 	MediaType string
 }
 
-// submitMsg is sent by the InputComponent when the user submits a text prompt.
+// SubmitMsg is sent by the InputComponent when the user submits a text prompt.
 // The parent model receives this and calls app.Run(Text) to start agent processing.
-type submitMsg struct {
+type SubmitMsg struct {
 	// Text is the user's input text to send to the agent.
 	Text string
 	// Images holds clipboard image attachments to send alongside the text.
@@ -20,10 +20,10 @@ type submitMsg struct {
 	Images []ImageAttachment
 }
 
-// cancelTimerExpiredMsg is sent by the tea.Tick command that starts when the user
+// CancelTimerExpiredMsg is sent by the tea.Tick command that starts when the user
 // presses ESC once during stateWorking. If this message arrives before the user
 // presses ESC a second time, the canceling state is reset to false.
-type cancelTimerExpiredMsg struct{}
+type CancelTimerExpiredMsg struct{}
 
 // --- Tree session events ---
 
@@ -42,14 +42,14 @@ type TreeNodeSelectedMsg struct {
 // TreeCancelledMsg is sent when the user cancels the tree selector (ESC).
 type TreeCancelledMsg struct{}
 
-// shellCommandMsg is sent by the InputComponent when the user submits a
+// ShellCommandMsg is sent by the InputComponent when the user submits a
 // ! or !! prefixed command. The parent model intercepts this to execute
 // the shell command directly instead of forwarding to the LLM.
 //
 // Matching pi's behavior:
 //   - !cmd  → run shell command, output INCLUDED in LLM context
 //   - !!cmd → run shell command, output EXCLUDED from LLM context
-type shellCommandMsg struct {
+type ShellCommandMsg struct {
 	// Command is the shell command to execute (prefix stripped).
 	Command string
 	// ExcludeFromContext is true for !! (output excluded from LLM context),
@@ -57,9 +57,9 @@ type shellCommandMsg struct {
 	ExcludeFromContext bool
 }
 
-// shellCommandResultMsg carries the result of a shell command execution
+// ShellCommandResultMsg carries the result of a shell command execution
 // back to the parent model for display.
-type shellCommandResultMsg struct {
+type ShellCommandResultMsg struct {
 	// Command is the original shell command that was executed.
 	Command string
 	// Output is the combined stdout/stderr output.
@@ -68,6 +68,6 @@ type shellCommandResultMsg struct {
 	ExitCode int
 	// Err is non-nil if the command failed to start or timed out.
 	Err error
-	// ExcludeFromContext mirrors the flag from shellCommandMsg.
+	// ExcludeFromContext mirrors the flag from ShellCommandMsg.
 	ExcludeFromContext bool
 }

internal/ui/exports.go

@@ -0,0 +1,62 @@
+package ui
+
+// This file re-exports types from subpackages for backward compatibility.
+// External importers can continue using ui.XXX without needing to import
+// from subpackages directly.
+
+import (
+	"github.com/mark3labs/kit/internal/ui/commands"
+	"github.com/mark3labs/kit/internal/ui/core"
+	"github.com/mark3labs/kit/internal/ui/fileutil"
+	"github.com/mark3labs/kit/internal/ui/prefs"
+	"github.com/mark3labs/kit/internal/ui/style"
+)
+
+// Re-export from core package
+type (
+	ImageAttachment       = core.ImageAttachment
+	SubmitMsg             = core.SubmitMsg
+	CancelTimerExpiredMsg = core.CancelTimerExpiredMsg
+	TreeNodeSelectedMsg   = core.TreeNodeSelectedMsg
+	TreeCancelledMsg      = core.TreeCancelledMsg
+	ShellCommandMsg       = core.ShellCommandMsg
+	ShellCommandResultMsg = core.ShellCommandResultMsg
+)
+
+// Re-export from commands package
+type (
+	SlashCommand     = commands.SlashCommand
+	ExtensionCommand = commands.ExtensionCommand
+)
+
+// Re-export functions from fileutil package
+var ProcessFileAttachments = fileutil.ProcessFileAttachments
+
+// Re-export from prefs package
+var (
+	LoadThemePreference         = prefs.LoadThemePreference
+	SaveThemePreference         = prefs.SaveThemePreference
+	LoadModelPreference         = prefs.LoadModelPreference
+	SaveModelPreference         = prefs.SaveModelPreference
+	LoadThinkingLevelPreference = prefs.LoadThinkingLevelPreference
+	SaveThinkingLevelPreference = prefs.SaveThinkingLevelPreference
+)
+
+// Re-export from style package
+type (
+	Theme               = style.Theme
+	MarkdownThemeColors = style.MarkdownThemeColors
+)
+
+var (
+	GetTheme                = style.GetTheme
+	SetTheme                = style.SetTheme
+	DefaultTheme            = style.DefaultTheme
+	ApplyTheme              = style.ApplyTheme
+	ApplyThemeWithoutSave   = style.ApplyThemeWithoutSave
+	ListThemes              = style.ListThemes
+	RegisterThemeFromConfig = style.RegisterThemeFromConfig
+	KitBanner               = style.KitBanner
+	AdaptiveColor           = style.AdaptiveColor
+	IsDarkBackground        = style.IsDarkBackground
+)

internal/ui/factory.go

@@ -25,7 +25,6 @@ type CLISetupOptions struct {
 	Agent          AgentInterface
 	ModelString    string
 	Debug          bool
-	Compact        bool
 	Quiet          bool
 	ShowDebug      bool   // Whether to show debug config
 	ProviderAPIKey string // For OAuth detection
@@ -76,7 +75,7 @@ func SetupCLI(opts *CLISetupOptions) (*CLI, error) {
 		return nil, nil // No CLI in quiet mode
 	}
 
-	cli, err := NewCLI(opts.Debug, opts.Compact)
+	cli, err := NewCLI(opts.Debug)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create CLI: %v", err)
 	}

internal/ui/file_suggestions.go

@@ -6,7 +6,6 @@ import (
 	"path/filepath"
 	"sort"
 	"strings"
-	"unicode/utf8"
 )
 
 // FileSuggestion represents a single file or directory suggestion for the @
@@ -345,44 +344,14 @@ func scoreFilePath(query, path string) int {
 	}
 
 	// Fuzzy character match on basename.
-	if score := fuzzyCharMatch(query, baseNameLower); score > 0 {
+	if score := fuzzyCharacterMatch(query, baseNameLower); score > 0 {
 		return score
 	}
 
 	// Fuzzy character match on full path.
-	if score := fuzzyCharMatch(query, pathLower); score > 0 {
+	if score := fuzzyCharacterMatch(query, pathLower); score > 0 {
 		return score - 50
 	}
 
 	return 0
 }
-
-// fuzzyCharMatch performs character-by-character fuzzy matching. Returns a
-// positive score if all query characters appear in order in the target.
-func fuzzyCharMatch(query, target string) int {
-	if utf8.RuneCountInString(query) > utf8.RuneCountInString(target) {
-		return 0
-	}
-
-	qRunes := []rune(query)
-	tRunes := []rune(target)
-	qi := 0
-	score := 100
-	consecutive := 0
-
-	for ti := 0; ti < len(tRunes) && qi < len(qRunes); ti++ {
-		if tRunes[ti] == qRunes[qi] {
-			qi++
-			consecutive++
-			score += consecutive * 5
-		} else {
-			consecutive = 0
-			score -= 2
-		}
-	}
-
-	if qi < len(qRunes) {
-		return 0
-	}
-	return score
-}

internal/ui/fileutil/processor.go

@@ -1,4 +1,4 @@
-package ui
+package fileutil
 
 import (
 	"fmt"

internal/ui/format.go

@@ -5,32 +5,34 @@ import (
 	"time"
 
 	"charm.land/lipgloss/v2"
+
+	"github.com/mark3labs/kit/internal/ui/style"
 )
 
-// Renderer is the interface satisfied by both MessageRenderer and
-// CompactRenderer. It allows model.go and cli.go to call rendering methods
-// without branching on compact mode.
+// Renderer is the interface satisfied by MessageRenderer. It allows model.go
+// and cli.go to call rendering methods uniformly.
 type Renderer interface {
 	RenderUserMessage(content string, timestamp time.Time) UIMessage
 	RenderAssistantMessage(content string, timestamp time.Time, modelName string) UIMessage
+	RenderReasoningBlock(content string, timestamp time.Time) UIMessage
 	RenderToolMessage(toolName, toolArgs, toolResult string, isError bool) UIMessage
 	RenderSystemMessage(content string, timestamp time.Time) UIMessage
 	RenderErrorMessage(errorMsg string, timestamp time.Time) UIMessage
 	RenderDebugMessage(message string, timestamp time.Time) UIMessage
 	RenderDebugConfigMessage(config map[string]any, timestamp time.Time) UIMessage
 	SetWidth(width int)
+	UpdateTheme()
 }
 
-// Compile-time checks that both renderers satisfy the Renderer interface.
+// Compile-time check that MessageRenderer satisfies the Renderer interface.
 var _ Renderer = (*MessageRenderer)(nil)
-var _ Renderer = (*CompactRenderer)(nil)
 
 // parseBashOutput parses <stdout>/<stderr> tagged output from bash tool
 // results, styling stderr with the theme's error color. Returns the
 // combined, styled output string with tags stripped.
 //
-// Shared by both MessageRenderer and CompactRenderer.
-func parseBashOutput(result string, theme Theme) string {
+// Shared by MessageRenderer.
+func parseBashOutput(result string, theme style.Theme) string {
 	var formattedResult strings.Builder
 	remaining := result
 

internal/ui/fuzzy.go

@@ -2,20 +2,22 @@ package ui
 
 import (
 	"strings"
+
+	"github.com/mark3labs/kit/internal/ui/commands"
 )
 
 // FuzzyMatch represents the result of a fuzzy string matching operation,
 // containing the matched command and its relevance score. Higher scores
 // indicate better matches.
 type FuzzyMatch struct {
-	Command *SlashCommand
+	Command *commands.SlashCommand
 	Score   int
 }
 
 // FuzzyMatchCommands performs fuzzy string matching on the provided slash commands
 // based on the query string. Returns a slice of matches sorted by relevance score
 // in descending order. An empty query returns all commands with zero scores.
-func FuzzyMatchCommands(query string, commands []SlashCommand) []FuzzyMatch {
+func FuzzyMatchCommands(query string, commands []commands.SlashCommand) []FuzzyMatch {
 	if query == "" || query == "/" {
 		// Return all commands when query is empty or just "/"
 		matches := make([]FuzzyMatch, len(commands))
@@ -57,7 +59,7 @@ func FuzzyMatchCommands(query string, commands []SlashCommand) []FuzzyMatch {
 }
 
 // fuzzyScore calculates the fuzzy match score for a command
-func fuzzyScore(query string, cmd *SlashCommand) int {
+func fuzzyScore(query string, cmd *commands.SlashCommand) int {
 	// Check exact match first
 	cmdName := strings.ToLower(strings.TrimPrefix(cmd.Name, "/"))
 	if cmdName == query {
@@ -113,19 +115,23 @@ func fuzzyScore(query string, cmd *SlashCommand) int {
 	return 0
 }
 
-// fuzzyCharacterMatch performs character-by-character fuzzy matching
+// fuzzyCharacterMatch performs character-by-character fuzzy matching using
+// rune-safe iteration so multi-byte Unicode characters are handled correctly.
+// Returns a positive score if all query runes appear in order within target.
 func fuzzyCharacterMatch(query, target string) int {
-	if len(query) > len(target) {
+	qRunes := []rune(query)
+	tRunes := []rune(target)
+	if len(qRunes) > len(tRunes) {
 		return 0
 	}
 
-	queryIdx := 0
+	qi := 0
 	score := 100
 	consecutiveMatches := 0
 
-	for i := 0; i < len(target) && queryIdx < len(query); i++ {
-		if target[i] == query[queryIdx] {
-			queryIdx++
+	for ti := 0; ti < len(tRunes) && qi < len(qRunes); ti++ {
+		if tRunes[ti] == qRunes[qi] {
+			qi++
 			consecutiveMatches++
 			score += consecutiveMatches * 10
 		} else {
@@ -135,7 +141,7 @@ func fuzzyCharacterMatch(query, target string) int {
 	}
 
 	// Must match all characters in query
-	if queryIdx < len(query) {
+	if qi < len(qRunes) {
 		return 0
 	}
 

internal/ui/input.go

@@ -10,6 +10,9 @@ import (
 	"charm.land/lipgloss/v2"
 
 	"github.com/mark3labs/kit/internal/clipboard"
+	"github.com/mark3labs/kit/internal/ui/commands"
+	"github.com/mark3labs/kit/internal/ui/core"
+	"github.com/mark3labs/kit/internal/ui/style"
 )
 
 // InputComponent is the interactive text input field for the parent AppModel.
@@ -29,7 +32,7 @@ import (
 // app.Run().
 type InputComponent struct {
 	textarea    textarea.Model
-	commands    []SlashCommand
+	commands    []commands.SlashCommand
 	showPopup   bool
 	filtered    []FuzzyMatch
 	selected    int
@@ -42,17 +45,17 @@ type InputComponent struct {
 	// Argument completion state. When the user types "/cmd " followed by
 	// a partial argument and the command has a Complete function, the popup
 	// switches to argument-completion mode showing suggestions from Complete.
-	argMode      bool           // true when showing arg completions
-	argCommand   string         // command prefix for arg mode (e.g. "/bookmark")
-	argSynthCmds []SlashCommand // backing storage for synthetic arg entries
+	argMode      bool                    // true when showing arg completions
+	argCommand   string                  // command prefix for arg mode (e.g. "/bookmark")
+	argSynthCmds []commands.SlashCommand // backing storage for synthetic arg entries
 
 	// File completion state. When the user types @ followed by a partial
 	// file path, the popup shows file/directory suggestions from the cwd.
-	fileMode        bool             // true when showing @file completions
-	filePrefix      string           // current text after @ being matched
-	fileAtStartIdx  int              // byte offset of @ in the textarea value
-	fileSuggestions []FileSuggestion // backing storage for file entries
-	fileSynthCmds   []SlashCommand   // synthetic SlashCommands wrapping file entries
+	fileMode        bool                    // true when showing @file completions
+	filePrefix      string                  // current text after @ being matched
+	fileAtStartIdx  int                     // byte offset of @ in the textarea value
+	fileSuggestions []FileSuggestion        // backing storage for file entries
+	fileSynthCmds   []commands.SlashCommand // synthetic commands.SlashCommands wrapping file entries
 
 	// cwd is the working directory used for @file path resolution and
 	// autocomplete suggestions. Set by the parent via SetCwd.
@@ -71,7 +74,7 @@ type InputComponent struct {
 
 	// pendingImages holds clipboard images attached to the next submission.
 	// Images are added via Ctrl+V and cleared on submit or Ctrl+U.
-	pendingImages []ImageAttachment
+	pendingImages []core.ImageAttachment
 
 	// history stores previously submitted prompts (most recent last).
 	// Limited to maxHistory entries; duplicates of the previous entry are
@@ -94,7 +97,7 @@ const maxHistory = 100
 
 // clipboardImageMsg is the result of an async clipboard image read.
 type clipboardImageMsg struct {
-	image *ImageAttachment
+	image *core.ImageAttachment
 	err   error
 }
 
@@ -119,7 +122,7 @@ func NewInputComponent(width int, title string, appCtrl AppController) *InputCom
 	)
 
 	// Style the textarea using theme colors.
-	theme := GetTheme()
+	theme := style.GetTheme()
 	styles := ta.Styles()
 	styles.Focused.Base = lipgloss.NewStyle()
 	styles.Focused.Placeholder = lipgloss.NewStyle().Foreground(theme.VeryMuted)
@@ -130,7 +133,7 @@ func NewInputComponent(width int, title string, appCtrl AppController) *InputCom
 
 	return &InputComponent{
 		textarea:    ta,
-		commands:    SlashCommands,
+		commands:    commands.SlashCommands,
 		width:       width,
 		popupHeight: 7,
 		title:       title,
@@ -329,7 +332,7 @@ func (s *InputComponent) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 					s.filePrefix = prefix
 					s.fileAtStartIdx = atIdx
 					s.fileSuggestions = suggestions
-					s.fileSynthCmds = make([]SlashCommand, len(suggestions))
+					s.fileSynthCmds = make([]commands.SlashCommand, len(suggestions))
 					s.filtered = make([]FuzzyMatch, len(suggestions))
 					for i, fs := range suggestions {
 						name := fs.RelPath
@@ -337,7 +340,7 @@ func (s *InputComponent) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 						if fs.IsDir {
 							desc = "directory"
 						}
-						s.fileSynthCmds[i] = SlashCommand{Name: name, Description: desc}
+						s.fileSynthCmds[i] = commands.SlashCommand{Name: name, Description: desc}
 						s.filtered[i] = FuzzyMatch{Command: &s.fileSynthCmds[i], Score: fs.Score}
 					}
 					s.selected = 0
@@ -396,34 +399,27 @@ func (s *InputComponent) handleSubmit(value string) tea.Cmd {
 		cmd := strings.TrimSpace(trimmed[2:])
 		if cmd != "" {
 			return func() tea.Msg {
-				return shellCommandMsg{Command: cmd, ExcludeFromContext: true}
+				return core.ShellCommandMsg{Command: cmd, ExcludeFromContext: true}
 			}
 		}
 	} else if strings.HasPrefix(trimmed, "!") {
 		cmd := strings.TrimSpace(trimmed[1:])
 		if cmd != "" {
 			return func() tea.Msg {
-				return shellCommandMsg{Command: cmd, ExcludeFromContext: false}
+				return core.ShellCommandMsg{Command: cmd, ExcludeFromContext: false}
 			}
 		}
 	}
 
 	// Resolve via canonical command lookup so aliases are handled uniformly.
-	// Only /quit and /clear are handled locally — /clear-queue must go
-	// through the parent model so it can update queueCount directly
-	// (calling ClearQueue here would skip the UI state update since we
-	// can't send events from within Update without deadlocking).
-	if sc := GetCommandByName(trimmed); sc != nil {
+	// Only /quit is handled locally — all other slash commands (including
+	// /clear and /clear-queue) are forwarded to the parent model via
+	// submitMsg so the parent can update its own state (ScrollList, queue
+	// counts, etc.) in one place.
+	if sc := commands.GetCommandByName(trimmed); sc != nil {
 		switch sc.Name {
 		case "/quit":
 			return tea.Quit
-
-		case "/clear":
-			if s.appCtrl != nil {
-				s.appCtrl.ClearMessages()
-			}
-			// Don't forward to app.Run(); just clear silently.
-			return nil
 		}
 	}
 
@@ -433,7 +429,7 @@ func (s *InputComponent) handleSubmit(value string) tea.Cmd {
 	images := s.pendingImages
 	s.pendingImages = nil
 	return func() tea.Msg {
-		return submitMsg{Text: trimmed, Images: images}
+		return core.SubmitMsg{Text: trimmed, Images: images}
 	}
 }
 
@@ -470,7 +466,7 @@ func (s *InputComponent) resetHistoryBrowsing() {
 func (s *InputComponent) View() tea.View {
 	containerStyle := lipgloss.NewStyle()
 
-	theme := GetTheme()
+	theme := style.GetTheme()
 
 	// PaddingLeft(3) aligns with message content: border(1) + paddingLeft(2).
 	titleStyle := lipgloss.NewStyle().
@@ -493,10 +489,8 @@ func (s *InputComponent) View() tea.View {
 	view.WriteString("\n")
 	view.WriteString(inputBoxStyle.Render(s.textarea.View()))
 
-	if s.showPopup && len(s.filtered) > 0 {
-		view.WriteString("\n")
-		view.WriteString(s.renderPopup())
-	}
+	// Popup is now rendered as a centered overlay in AppModel.View()
+	// instead of inline here to prevent bottom overflow
 
 	// Show image attachment indicator when images are pending.
 	if len(s.pendingImages) > 0 {
@@ -544,19 +538,62 @@ func (s *InputComponent) View() tea.View {
 }
 
 // renderPopup renders the autocomplete popup for slash command suggestions.
-func (s *InputComponent) renderPopup() string {
-	theme := GetTheme()
+// When rendered inline (not centered), returns the styled popup content.
+// RenderPopupCentered renders the popup as a centered overlay.
+func (s *InputComponent) RenderPopupCentered(termWidth, termHeight int) string {
+	if !s.showPopup || len(s.filtered) == 0 {
+		return ""
+	}
+
+	popupContent := s.renderPopupWithOptions(true)
+
+	// Center popup using lipgloss.Place
+	positioned := lipgloss.Place(
+		termWidth,
+		termHeight,
+		lipgloss.Center,
+		lipgloss.Center,
+		popupContent,
+	)
+
+	return positioned
+}
+
+// renderPopupWithOptions renders the popup content with optional center styling.
+func (s *InputComponent) renderPopupWithOptions(centered bool) string {
+	theme := style.GetTheme()
 	popupWidth := max(s.width-4, 20)
+
+	// Use the theme background for the popup - the full-width item backgrounds
+	// and primary-colored selection will provide sufficient contrast
+	popupBg := theme.Background
+
 	popupStyle := lipgloss.NewStyle().
 		Border(lipgloss.RoundedBorder()).
-		BorderForeground(theme.MutedBorder).
+		BorderForeground(theme.Primary).
+		Background(popupBg).
 		Padding(1, 2).
 		Width(popupWidth).
-		MarginLeft(0)
+		MarginLeft(0).
+		MarginBottom(1) // Visual depth/shadow effect
 
 	// Inner content width: popup minus border (2) and horizontal padding (4).
 	innerWidth := max(popupWidth-6, 10)
 
+	// Item background styles for high contrast
+	normalItemBg := lipgloss.NewStyle().
+		Background(popupBg).
+		Foreground(theme.Text).
+		Width(innerWidth).
+		Padding(0, 1)
+
+	selectedItemBg := lipgloss.NewStyle().
+		Background(theme.Primary).
+		Foreground(theme.Background).
+		Width(innerWidth).
+		Padding(0, 1).
+		Bold(true)
+
 	var items []string
 
 	visibleItems := min(len(s.filtered), s.popupHeight)
@@ -570,44 +607,45 @@ func (s *InputComponent) renderPopup() string {
 		match := s.filtered[i]
 		sc := match.Command
 
+		// Choose the appropriate background style
+		itemStyle := normalItemBg
+		if i == s.selected {
+			itemStyle = selectedItemBg
+		}
+
+		// Build indicator with proper coloring
 		var indicator string
 		if i == s.selected {
-			indicator = lipgloss.NewStyle().Foreground(theme.Primary).Render("> ")
+			indicator = "> "
 		} else {
 			indicator = "  "
 		}
 
-		nameStyle := lipgloss.NewStyle().Foreground(theme.Secondary).Bold(true)
-		descStyle := lipgloss.NewStyle().Foreground(theme.Muted)
-		if i == s.selected {
-			nameStyle = nameStyle.Foreground(theme.Primary)
-			descStyle = descStyle.Foreground(theme.Text)
-		}
-
+		// Build content with name and description
+		var content string
 		if s.fileMode {
-			// File mode: use full width for the path, show description
-			// (e.g. "directory") inline after a gap.
+			// File mode: use full width for the path, show description inline
 			maxNameLen := max(innerWidth-16, 8)
 			displayName := sc.Name
 			if len(displayName) > maxNameLen && maxNameLen > 3 {
 				displayName = displayName[:maxNameLen-3] + "..."
 			}
-			name := nameStyle.Render(displayName)
+
 			if sc.Description != "" && innerWidth > 30 {
-				items = append(items, indicator+name+"  "+descStyle.Render(sc.Description))
+				content = indicator + displayName + "  " + sc.Description
 			} else {
-				items = append(items, indicator+name)
+				content = indicator + displayName
 			}
 		} else {
-			// Line layout: indicator(2) + name(nameWidth-2 visual) + desc.
+			// Line layout: indicator(2) + name(nameWidth-2 visual) + desc
 			if innerWidth < 20 {
-				// Very narrow: show truncated name only, no fixed column.
+				// Very narrow: show truncated name only
 				displayName := sc.Name
 				maxName := max(innerWidth-2, 3)
 				if len(displayName) > maxName {
 					displayName = displayName[:maxName-1] + "…"
 				}
-				items = append(items, indicator+nameStyle.Render(displayName))
+				content = indicator + displayName
 			} else {
 				nameWidth := 15
 				if innerWidth < 25 {
@@ -618,33 +656,41 @@ func (s *InputComponent) renderPopup() string {
 				if len(displayName) > maxNameChars {
 					displayName = displayName[:maxNameChars-1] + "…"
 				}
-				name := nameStyle.Width(maxNameChars).Render(displayName)
 
-				// Description gets remaining space.
+				// Description gets remaining space
 				maxDescLen := max(innerWidth-nameWidth, 0)
 				desc := sc.Description
-				if maxDescLen < 4 {
-					items = append(items, indicator+name)
-				} else {
+				if maxDescLen >= 4 && desc != "" {
 					if len(desc) > maxDescLen {
 						desc = desc[:maxDescLen-3] + "..."
 					}
-					items = append(items, indicator+name+descStyle.Render(desc))
+					content = indicator + lipgloss.NewStyle().Width(maxNameChars).Render(displayName) + desc
+				} else {
+					content = indicator + displayName
 				}
 			}
 		}
+
+		items = append(items, itemStyle.Render(content))
 	}
 
+	// Add scroll indicators with background
+	scrollStyle := lipgloss.NewStyle().
+		Background(popupBg).
+		Foreground(theme.VeryMuted).
+		Width(innerWidth).
+		Padding(0, 1)
+
 	if startIdx > 0 {
-		items = append([]string{lipgloss.NewStyle().Foreground(theme.VeryMuted).Render("  ↑ more above")}, items...)
+		items = append([]string{scrollStyle.Render("  ↑ more above")}, items...)
 	}
 	if endIdx < len(s.filtered) {
-		items = append(items, lipgloss.NewStyle().Foreground(theme.VeryMuted).Render("  ↓ more below"))
+		items = append(items, scrollStyle.Render("  ↓ more below"))
 	}
 
 	content := strings.Join(items, "\n")
 
-	// Adapt footer text to available width.
+	// Adapt footer text to available width with background
 	var footerText string
 	if innerWidth >= 50 {
 		footerText = "↑↓ navigate • tab complete • ↵ select • esc dismiss"
@@ -653,7 +699,10 @@ func (s *InputComponent) renderPopup() string {
 	} else {
 		footerText = "↑↓ tab ↵ esc"
 	}
-	footer := lipgloss.NewStyle().Foreground(theme.VeryMuted).Italic(true).
+	footer := lipgloss.NewStyle().
+		Background(popupBg).
+		Foreground(theme.VeryMuted).
+		Italic(true).
 		Render(footerText)
 
 	return popupStyle.Render(content + "\n\n" + footer)
@@ -683,10 +732,10 @@ func (s *InputComponent) completeArgs(line string) []FuzzyMatch {
 
 	s.argMode = true
 	s.argCommand = cmdName
-	s.argSynthCmds = make([]SlashCommand, len(suggestions))
+	s.argSynthCmds = make([]commands.SlashCommand, len(suggestions))
 	s.filtered = make([]FuzzyMatch, len(suggestions))
 	for i, sug := range suggestions {
-		s.argSynthCmds[i] = SlashCommand{Name: sug}
+		s.argSynthCmds[i] = commands.SlashCommand{Name: sug}
 		s.filtered[i] = FuzzyMatch{Command: &s.argSynthCmds[i]}
 	}
 	return s.filtered
@@ -694,7 +743,7 @@ func (s *InputComponent) completeArgs(line string) []FuzzyMatch {
 
 // findCommandWithComplete looks up a command by name that has a non-nil
 // Complete function.
-func (s *InputComponent) findCommandWithComplete(name string) *SlashCommand {
+func (s *InputComponent) findCommandWithComplete(name string) *commands.SlashCommand {
 	for i := range s.commands {
 		if s.commands[i].Name == name && s.commands[i].Complete != nil {
 			return &s.commands[i]
@@ -712,7 +761,7 @@ func readClipboardImageCmd() tea.Cmd {
 			return clipboardImageMsg{err: err}
 		}
 		return clipboardImageMsg{
-			image: &ImageAttachment{
+			image: &core.ImageAttachment{
 				Data:      img.Data,
 				MediaType: img.MediaType,
 			},
@@ -722,7 +771,7 @@ func readClipboardImageCmd() tea.Cmd {
 
 // ClearPendingImages removes all pending image attachments and returns them.
 // Used by the parent model when consuming images for submission.
-func (s *InputComponent) ClearPendingImages() []ImageAttachment {
+func (s *InputComponent) ClearPendingImages() []core.ImageAttachment {
 	images := s.pendingImages
 	s.pendingImages = nil
 	return images

internal/ui/message_items.go

@@ -0,0 +1,381 @@
+package ui
+
+import (
+	"fmt"
+	"strings"
+	"time"
+
+	"charm.land/lipgloss/v2"
+
+	"github.com/mark3labs/kit/internal/ui/render"
+	"github.com/mark3labs/kit/internal/ui/style"
+)
+
+// --------------------------------------------------------------------------
+// MessageItem implementations for ScrollList
+// --------------------------------------------------------------------------
+
+// TextMessageItem represents a completed text message (user or assistant)
+// in the scrollback. It uses pre-rendered styled content from MessageRenderer.
+type TextMessageItem struct {
+	id          string
+	role        string // "user" or "assistant"
+	content     string // Raw content (for re-rendering if needed)
+	preRendered string // Pre-rendered styled content from MessageRenderer
+	timestamp   time.Time
+}
+
+// NewTextMessageItem creates a new text message for the scrollback.
+// The content should be pre-rendered using MessageRenderer for proper styling.
+func NewTextMessageItem(id string, role string, content string) *TextMessageItem {
+	return &TextMessageItem{
+		id:        id,
+		role:      role,
+		content:   content,
+		timestamp: time.Now(),
+	}
+}
+
+// NewStyledMessageItem creates a message item with pre-rendered styled content.
+// This is the preferred way to create messages when you have styled content from MessageRenderer.
+func NewStyledMessageItem(id string, role string, rawContent string, preRendered string) *TextMessageItem {
+	return &TextMessageItem{
+		id:          id,
+		role:        role,
+		content:     rawContent,
+		preRendered: preRendered,
+		timestamp:   time.Now(),
+	}
+}
+
+func (m *TextMessageItem) ID() string {
+	return m.id
+}
+
+func (m *TextMessageItem) Render(width int) string {
+	// If we have pre-rendered styled content, return it
+	if m.preRendered != "" {
+		return m.preRendered
+	}
+
+	// Fallback to simple formatting if no pre-rendered content
+	return m.renderContent(width)
+}
+
+func (m *TextMessageItem) Height() int {
+	rendered := m.Render(0) // Width doesn't matter since we use pre-rendered
+	if rendered == "" {
+		return 0
+	}
+	return strings.Count(rendered, "\n") + 1
+}
+
+func (m *TextMessageItem) renderContent(width int) string {
+	var parts []string
+
+	// Role indicator
+	if m.role == "user" {
+		parts = append(parts, "│ ▸ You")
+	} else {
+		parts = append(parts, "") // Assistant messages start without role
+	}
+
+	// Content with simple wrapping
+	contentWidth := max(width-4, 20)
+
+	for line := range strings.SplitSeq(m.content, "\n") {
+		if len(line) <= contentWidth {
+			parts = append(parts, "│ "+line)
+		} else {
+			// Basic wrap
+			for len(line) > contentWidth {
+				parts = append(parts, "│ "+line[:contentWidth])
+				line = line[contentWidth:]
+			}
+			if len(line) > 0 {
+				parts = append(parts, "│ "+line)
+			}
+		}
+	}
+
+	return strings.Join(parts, "\n")
+}
+
+// --------------------------------------------------------------------------
+// StreamingMessageItem - Live streaming assistant/reasoning text
+// --------------------------------------------------------------------------
+
+// StreamingMessageItem represents actively streaming assistant or reasoning text.
+// It accumulates content chunks and re-renders on each update for live display.
+type StreamingMessageItem struct {
+	id            string
+	role          string // "assistant" or "reasoning"
+	content       string // Accumulated streaming content
+	timestamp     time.Time
+	startTime     time.Time // When streaming started (for live duration counter)
+	modelName     string
+	streaming     bool          // true while actively streaming
+	finalDuration time.Duration // Frozen duration when complete
+	cachedRender  string
+	cachedWidth   int
+}
+
+// NewStreamingMessageItem creates a new streaming message item.
+func NewStreamingMessageItem(id, role string, modelName string) *StreamingMessageItem {
+	now := time.Now()
+	return &StreamingMessageItem{
+		id:        id,
+		role:      role,
+		timestamp: now,
+		startTime: now,
+		modelName: modelName,
+		streaming: true,
+	}
+}
+
+// ID returns the unique identifier.
+func (s *StreamingMessageItem) ID() string {
+	return s.id
+}
+
+// Render renders the streaming message with live content.
+func (s *StreamingMessageItem) Render(width int) string {
+	// For reasoning, never cache - we need live duration updates
+	// For assistant, cache is OK
+	if s.role != "reasoning" && s.cachedWidth == width && s.cachedRender != "" {
+		return s.cachedRender
+	}
+
+	var rendered string
+	if s.role == "reasoning" {
+		// Calculate duration in milliseconds for render.ReasoningBlock
+		var durationMs int64
+		if s.finalDuration > 0 {
+			durationMs = s.finalDuration.Milliseconds()
+		} else if !s.startTime.IsZero() {
+			durationMs = time.Since(s.startTime).Milliseconds()
+		}
+		ty := createTypography(style.GetTheme())
+		rendered = render.ReasoningBlock(s.content, durationMs, ty, style.GetTheme())
+	} else {
+		// Render as assistant message
+		rendered = render.AssistantBlock(s.content, width, style.GetTheme())
+	}
+
+	// Cache and return (but reasoning is never cached due to live duration)
+	if s.role != "reasoning" {
+		s.cachedRender = rendered
+		s.cachedWidth = width
+	}
+	return rendered
+}
+
+// Height returns the number of lines.
+func (s *StreamingMessageItem) Height() int {
+	// For reasoning blocks, cachedRender is never populated (rendering is
+	// width-independent and includes a live timer). Fall back to Render(0)
+	// so callers always get the correct height.
+	rendered := s.cachedRender
+	if rendered == "" {
+		rendered = s.Render(0)
+	}
+	if rendered == "" {
+		return 0
+	}
+	return strings.Count(rendered, "\n") + 1
+}
+
+// AppendChunk adds a content chunk and invalidates the render cache.
+func (s *StreamingMessageItem) AppendChunk(chunk string) {
+	s.content += chunk
+	s.cachedWidth = 0 // Invalidate cache
+}
+
+// MarkComplete marks the streaming message as complete and freezes the duration.
+func (s *StreamingMessageItem) MarkComplete() {
+	s.streaming = false
+	// Freeze the duration for reasoning blocks
+	if s.role == "reasoning" && !s.startTime.IsZero() {
+		s.finalDuration = time.Since(s.startTime)
+	}
+}
+
+// --------------------------------------------------------------------------
+// StreamingBashOutputItem - Live bash command output
+// --------------------------------------------------------------------------
+
+// StreamingBashOutputItem represents live bash command output.
+type StreamingBashOutputItem struct {
+	id           string
+	command      string
+	stdoutLines  []string
+	stderrLines  []string
+	maxLines     int
+	complete     bool
+	cachedRender string
+	cachedWidth  int
+}
+
+// NewStreamingBashOutputItem creates a new streaming bash output item.
+func NewStreamingBashOutputItem(id string, command string) *StreamingBashOutputItem {
+	return &StreamingBashOutputItem{
+		id:          id,
+		command:     command,
+		stdoutLines: make([]string, 0),
+		stderrLines: make([]string, 0),
+		maxLines:    100, // Cap lines to prevent memory issues
+		complete:    false,
+	}
+}
+
+func (m *StreamingBashOutputItem) ID() string {
+	return m.id
+}
+
+func (m *StreamingBashOutputItem) Render(width int) string {
+	// Return cached if width matches and complete
+	if m.complete && m.cachedWidth == width && m.cachedRender != "" {
+		return m.cachedRender
+	}
+
+	theme := style.GetTheme()
+	var parts []string
+
+	// Header with command
+	if m.command != "" {
+		headerStyle := lipgloss.NewStyle().
+			Foreground(theme.Muted).
+			Italic(true)
+		parts = append(parts, headerStyle.Render(fmt.Sprintf("▸ %s", m.command)))
+	}
+
+	const lineIndent = "  "
+	lineWidth := width - len(lineIndent)
+
+	// Stdout lines
+	if len(m.stdoutLines) > 0 {
+		outputStyle := lipgloss.NewStyle().
+			Foreground(theme.Text).
+			Background(theme.CodeBg).
+			PaddingLeft(1).
+			Width(lineWidth)
+		for _, line := range m.stdoutLines {
+			parts = append(parts, lineIndent+outputStyle.Render(line))
+		}
+	}
+
+	// Stderr lines
+	if len(m.stderrLines) > 0 {
+		stderrStyle := lipgloss.NewStyle().
+			Foreground(theme.Error).
+			Background(theme.CodeBg).
+			PaddingLeft(1).
+			Width(lineWidth)
+		for _, line := range m.stderrLines {
+			parts = append(parts, lineIndent+stderrStyle.Render(line))
+		}
+	}
+
+	result := strings.Join(parts, "\n")
+	if m.complete {
+		m.cachedRender = result
+		m.cachedWidth = width
+	}
+	return result
+}
+
+func (m *StreamingBashOutputItem) Height() int {
+	if m.cachedRender != "" {
+		return strings.Count(m.cachedRender, "\n") + 1
+	}
+	// Estimate: command header + stdout + stderr
+	return 1 + len(m.stdoutLines) + len(m.stderrLines)
+}
+
+// AppendStdout adds a stdout line to the output.
+func (m *StreamingBashOutputItem) AppendStdout(line string) {
+	m.stdoutLines = append(m.stdoutLines, line)
+	// Cap lines
+	if len(m.stdoutLines) > m.maxLines {
+		m.stdoutLines = m.stdoutLines[len(m.stdoutLines)-m.maxLines:]
+	}
+	m.cachedWidth = 0 // Invalidate cache
+}
+
+// AppendStderr adds a stderr line to the output.
+func (m *StreamingBashOutputItem) AppendStderr(line string) {
+	m.stderrLines = append(m.stderrLines, line)
+	// Cap lines
+	if len(m.stderrLines) > m.maxLines {
+		m.stderrLines = m.stderrLines[len(m.stderrLines)-m.maxLines:]
+	}
+	m.cachedWidth = 0 // Invalidate cache
+}
+
+// MarkComplete marks the bash output as complete.
+func (m *StreamingBashOutputItem) MarkComplete() {
+	m.complete = true
+}
+
+// --------------------------------------------------------------------------
+// SystemMessageItem - System messages (commands, info, errors)
+// --------------------------------------------------------------------------
+
+// SystemMessageItem represents a system message (commands, info, errors).
+type SystemMessageItem struct {
+	id           string
+	content      string
+	timestamp    time.Time
+	cachedRender string
+	cachedWidth  int
+}
+
+// NewSystemMessageItem creates a new system message for the scrollback.
+func NewSystemMessageItem(id, content string) *SystemMessageItem {
+	return &SystemMessageItem{
+		id:        id,
+		content:   content,
+		timestamp: time.Now(),
+	}
+}
+
+func (m *SystemMessageItem) ID() string {
+	return m.id
+}
+
+func (m *SystemMessageItem) Render(width int) string {
+	// Return cached render if width matches
+	if m.cachedWidth == width && m.cachedRender != "" {
+		return m.cachedRender
+	}
+
+	// Simple system message formatting
+	rendered := "│ " + strings.ReplaceAll(m.content, "\n", "\n│ ")
+
+	// Cache and return
+	m.cachedRender = rendered
+	m.cachedWidth = width
+	return rendered
+}
+
+func (m *SystemMessageItem) Height() int {
+	if m.cachedRender != "" {
+		return strings.Count(m.cachedRender, "\n") + 1
+	}
+	// Estimate
+	if m.cachedWidth > 0 {
+		return (len(m.content) / max(m.cachedWidth-10, 40)) + 3
+	}
+	return 3
+}
+
+// --------------------------------------------------------------------------
+// Helper: generateMessageID
+// --------------------------------------------------------------------------
+
+var messageCounter = 0
+
+func generateMessageID() string {
+	messageCounter++
+	return fmt.Sprintf("msg-%d-%d", time.Now().UnixNano(), messageCounter)
+}

internal/ui/messages.go

@@ -3,17 +3,16 @@ package ui
 import (
 	"encoding/json"
 	"fmt"
-	"regexp"
 	"sort"
 	"strings"
 	"time"
 
 	"charm.land/lipgloss/v2"
 	"github.com/indaco/herald"
-)
 
-// ansiEscapeRe matches ANSI escape sequences used for terminal styling.
-var ansiEscapeRe = regexp.MustCompile(`\x1b\[[0-9;]*m`)
+	"github.com/mark3labs/kit/internal/ui/render"
+	"github.com/mark3labs/kit/internal/ui/style"
+)
 
 // MessageType represents different categories of messages displayed in the UI,
 // each with distinct visual styling and formatting rules.
@@ -41,27 +40,9 @@ type UIMessage struct {
 	Streaming bool
 }
 
-// toolDisplayNames maps raw tool names to human-friendly display names.
-var toolDisplayNames = map[string]string{
-	"bash":  "Bash",
-	"read":  "Read",
-	"write": "Write",
-	"edit":  "Edit",
-	"grep":  "Grep",
-	"find":  "Find",
-	"ls":    "Ls",
-}
-
-// getTheme returns the current theme (helper for compact_renderer.go)
-func getTheme() Theme {
-	return GetTheme()
-}
-
-// toolDisplayName returns a human-friendly display name for a tool.
+// toolDisplayName returns a human-friendly display name for a tool,
+// title-casing the first letter of the raw name.
 func toolDisplayName(rawName string) string {
-	if display, ok := toolDisplayNames[rawName]; ok {
-		return display
-	}
 	if rawName != "" {
 		return strings.ToUpper(rawName[:1]) + rawName[1:]
 	}
@@ -160,7 +141,7 @@ func newMessageRenderer(width int, debug bool) *MessageRenderer {
 	return &MessageRenderer{
 		width: width,
 		debug: debug,
-		ty:    createTypography(GetTheme()),
+		ty:    createTypography(style.GetTheme()),
 	}
 }
 
@@ -171,12 +152,7 @@ func (r *MessageRenderer) SetWidth(width int) {
 
 // RenderUserMessage renders a user's input message using herald Tip alert
 func (r *MessageRenderer) RenderUserMessage(content string, timestamp time.Time) UIMessage {
-	if strings.TrimSpace(content) == "" {
-		content = "(empty message)"
-	}
-
-	rendered := r.ty.Tip(content)
-	rendered = lipgloss.NewStyle().MarginBottom(1).Render(rendered)
+	rendered := render.UserBlock(content, r.ty, style.GetTheme())
 
 	return UIMessage{
 		Type:      UserMessage,
@@ -188,18 +164,21 @@ func (r *MessageRenderer) RenderUserMessage(content string, timestamp time.Time)
 
 // RenderAssistantMessage renders an AI assistant's response
 func (r *MessageRenderer) RenderAssistantMessage(content string, timestamp time.Time, modelName string) UIMessage {
-	if strings.TrimSpace(content) == "" {
-		return UIMessage{
-			Type:      AssistantMessage,
-			Content:   "",
-			Height:    0,
-			Timestamp: timestamp,
-		}
-	}
+	rendered := render.AssistantBlock(content, r.width, style.GetTheme())
 
-	// Use markdown rendering with Chroma syntax highlighting
-	rendered := toMarkdown(content, r.width-4)
-	rendered = lipgloss.NewStyle().MarginBottom(1).Render(rendered)
+	return UIMessage{
+		Type:      AssistantMessage,
+		Content:   rendered,
+		Height:    lipgloss.Height(rendered),
+		Timestamp: timestamp,
+	}
+}
+
+// RenderReasoningBlock renders a reasoning/thinking block with the same styling
+// as live streaming: muted italic text with margin. This is used when resuming
+// sessions to display saved reasoning content.
+func (r *MessageRenderer) RenderReasoningBlock(content string, timestamp time.Time) UIMessage {
+	rendered := render.ReasoningBlock(content, 0, r.ty, style.GetTheme())
 
 	return UIMessage{
 		Type:      AssistantMessage,
@@ -211,12 +190,7 @@ func (r *MessageRenderer) RenderAssistantMessage(content string, timestamp time.
 
 // RenderSystemMessage renders KIT system messages using herald Note alert
 func (r *MessageRenderer) RenderSystemMessage(content string, timestamp time.Time) UIMessage {
-	if strings.TrimSpace(content) == "" {
-		content = "No content available"
-	}
-
-	rendered := r.ty.Note(content)
-	rendered = lipgloss.NewStyle().MarginBottom(1).Render(rendered)
+	rendered := render.SystemBlock(content, r.ty, style.GetTheme())
 
 	return UIMessage{
 		Type:      SystemMessage,
@@ -242,7 +216,7 @@ func (r *MessageRenderer) RenderDebugMessage(message string, timestamp time.Time
 		header,
 		r.ty.P(strings.Join(formattedLines, "\n")),
 	)
-	content = lipgloss.NewStyle().MarginBottom(1).Render(content)
+	content = styleMarginBottom1.Render(content)
 
 	return UIMessage{
 		Content: content,
@@ -270,7 +244,7 @@ func (r *MessageRenderer) RenderDebugConfigMessage(config map[string]any, timest
 	} else {
 		content = header
 	}
-	content = lipgloss.NewStyle().MarginBottom(1).Render(content)
+	content = styleMarginBottom1.Render(content)
 
 	return UIMessage{
 		Type:      SystemMessage,
@@ -282,8 +256,7 @@ func (r *MessageRenderer) RenderDebugConfigMessage(config map[string]any, timest
 
 // RenderErrorMessage renders error notifications
 func (r *MessageRenderer) RenderErrorMessage(errorMsg string, timestamp time.Time) UIMessage {
-	rendered := r.ty.Caution(errorMsg)
-	rendered = lipgloss.NewStyle().MarginBottom(1).Render(rendered)
+	rendered := render.ErrorBlock(errorMsg, r.ty, style.GetTheme())
 
 	return UIMessage{
 		Type:      ErrorMessage,
@@ -293,39 +266,6 @@ func (r *MessageRenderer) RenderErrorMessage(errorMsg string, timestamp time.Tim
 	}
 }
 
-// RenderToolCallMessage renders a notification that a tool is being executed
-func (r *MessageRenderer) RenderToolCallMessage(toolName, toolArgs string, timestamp time.Time) UIMessage {
-	timeStr := timestamp.Local().Format("15:04")
-
-	var argsContent string
-	if toolArgs != "" && toolArgs != "{}" {
-		argsContent = r.ty.Italic(fmt.Sprintf("Arguments: %s", r.formatToolArgs(toolArgs)))
-	}
-
-	info := fmt.Sprintf(" Executing %s (%s)", toolName, timeStr)
-	infoStyled := r.ty.Small(info)
-
-	var fullContent string
-	if argsContent != "" {
-		fullContent = r.ty.Compose(
-			argsContent,
-			infoStyled,
-		)
-	} else {
-		fullContent = infoStyled
-	}
-
-	rendered := r.ty.Warning(fullContent)
-	rendered = lipgloss.NewStyle().MarginBottom(1).Render(rendered)
-
-	return UIMessage{
-		Type:      ToolCallMessage,
-		Content:   rendered,
-		Height:    lipgloss.Height(rendered),
-		Timestamp: timestamp,
-	}
-}
-
 // RenderToolMessage renders a unified tool block
 func (r *MessageRenderer) RenderToolMessage(toolName, toolArgs, toolResult string, isError bool) UIMessage {
 	var extRd *ToolRendererData
@@ -348,16 +288,16 @@ func (r *MessageRenderer) RenderToolMessage(toolName, toolArgs, toolResult strin
 	}
 
 	var icon string
-	iconColor := GetTheme().Success
+	iconColor := style.GetTheme().Success
 	if isError {
 		icon = "×"
-		iconColor = GetTheme().Error
+		iconColor = style.GetTheme().Error
 	} else {
 		icon = "✓"
 	}
 
 	// Style the tool name with color
-	theme := GetTheme()
+	theme := style.GetTheme()
 	nameColor := theme.Info
 	if isError {
 		nameColor = theme.Error
@@ -376,7 +316,7 @@ func (r *MessageRenderer) RenderToolMessage(toolName, toolArgs, toolResult strin
 	if extRd != nil && extRd.RenderBody != nil {
 		body = extRd.RenderBody(toolResult, isError, r.width-8)
 		if body != "" && extRd.BodyMarkdown {
-			body = strings.TrimSuffix(toMarkdown(body, r.width-8), "\n")
+			body = strings.TrimSuffix(style.ToMarkdown(body, r.width-8), "\n")
 		}
 	}
 	if body == "" {
@@ -394,13 +334,19 @@ func (r *MessageRenderer) RenderToolMessage(toolName, toolArgs, toolResult strin
 		body = r.ty.Italic("(no output)")
 	}
 
+	// Wrap all tool errors in a herald Caution alert so the error text
+	// renders inside a contained block instead of spilling into the layout.
+	if isError && strings.TrimSpace(body) != "" {
+		body = r.ty.Alert(herald.AlertCaution, body)
+	}
+
 	// Compose: icon + name + params, then body
 	fullContent := r.ty.Compose(
 		headerLine,
 		"",
 		body,
 	)
-	fullContent = lipgloss.NewStyle().MarginBottom(1).Render(fullContent)
+	fullContent = styleMarginBottom1.Render(fullContent)
 
 	return UIMessage{
 		Type:    ToolMessage,
@@ -409,29 +355,6 @@ func (r *MessageRenderer) RenderToolMessage(toolName, toolArgs, toolResult strin
 	}
 }
 
-// formatToolArgs formats tool arguments for display
-func (r *MessageRenderer) formatToolArgs(args string) string {
-	args = strings.TrimSpace(args)
-	if strings.HasPrefix(args, "{") && strings.HasSuffix(args, "}") {
-		args = strings.TrimPrefix(args, "{")
-		args = strings.TrimSuffix(args, "}")
-		args = strings.TrimSpace(args)
-	}
-
-	if args == "" {
-		return "(no arguments)"
-	}
-
-	if !r.debug {
-		maxLen := 100
-		if len(args) > maxLen {
-			return args[:maxLen] + "..."
-		}
-	}
-
-	return args
-}
-
 // formatToolResult formats tool results based on tool type
 func (r *MessageRenderer) formatToolResult(toolName, result string) string {
 	if !r.debug {
@@ -445,7 +368,7 @@ func (r *MessageRenderer) formatToolResult(toolName, result string) string {
 	if strings.Contains(toolName, "bash") || strings.Contains(toolName, "command") ||
 		strings.Contains(toolName, "shell") {
 		if strings.Contains(result, "<stdout>") || strings.Contains(result, "<stderr>") {
-			return parseBashOutput(result, GetTheme())
+			return parseBashOutput(result, style.GetTheme())
 		}
 	}
 
@@ -453,7 +376,7 @@ func (r *MessageRenderer) formatToolResult(toolName, result string) string {
 }
 
 // createTypography creates a typography instance from theme
-func createTypography(theme Theme) *herald.Typography {
+func createTypography(theme style.Theme) *herald.Typography {
 	return herald.New(
 		herald.WithPalette(herald.ColorPalette{
 			Primary:   theme.Primary,
@@ -482,14 +405,8 @@ func createTypography(theme Theme) *herald.Typography {
 	)
 }
 
-// removeBlankLines removes lines that are visually blank from rendered output.
-func removeBlankLines(s string) string {
-	lines := strings.Split(s, "\n")
-	filtered := lines[:0]
-	for _, line := range lines {
-		if strings.TrimSpace(ansiEscapeRe.ReplaceAllString(line, "")) != "" {
-			filtered = append(filtered, line)
-		}
-	}
-	return strings.Join(filtered, "\n")
+// UpdateTheme refreshes the renderer's typography instance with colors from
+// the current theme. This is called when the user changes themes via /theme.
+func (r *MessageRenderer) UpdateTheme() {
+	r.ty = createTypography(style.GetTheme())
 }

internal/ui/model_selector.go

@@ -5,9 +5,7 @@ import (
 	"sort"
 	"strings"
 
-	"charm.land/bubbles/v2/key"
 	tea "charm.land/bubbletea/v2"
-	"charm.land/lipgloss/v2"
 
 	"github.com/mark3labs/kit/internal/models"
 )
@@ -29,16 +27,14 @@ type ModelSelectedMsg struct {
 // ModelSelectorCancelledMsg is sent when the user cancels the selector.
 type ModelSelectorCancelledMsg struct{}
 
-// ModelSelectorComponent is a full-screen Bubble Tea component that displays
-// a filterable list of available models. It follows the same pattern as
-// TreeSelectorComponent: inline text search, scrolling list, and custom
-// messages for result delivery.
+// ModelSelectorComponent is a Bubble Tea component that displays a filterable
+// list of available models as a centered overlay popup. It delegates rendering
+// and keyboard navigation to PopupList and converts results into the
+// ModelSelectedMsg / ModelSelectorCancelledMsg messages expected by AppModel.
 type ModelSelectorComponent struct {
-	allModels    []ModelEntry // all available models (pre-sorted)
-	filtered     []ModelEntry // subset matching the current search
-	cursor       int
-	search       string
-	currentModel string // "provider/model" of the active model (for checkmark)
+	popup        *PopupList
+	allModels    []ModelEntry // kept for the custom filter callback
+	currentModel string       // "provider/model" of the active model
 	width        int
 	height       int
 	active       bool
@@ -50,7 +46,7 @@ func NewModelSelector(currentModel string, width, height int) *ModelSelectorComp
 	registry := models.GetGlobalRegistry()
 	var allModels []ModelEntry
 
-	for _, providerID := range registry.GetFantasyProviders() {
+	for _, providerID := range registry.GetLLMProviders() {
 		// Only include providers with valid API keys configured.
 		if err := registry.ValidateEnvironment(providerID, ""); err != nil {
 			continue
@@ -80,24 +76,31 @@ func NewModelSelector(currentModel string, width, height int) *ModelSelectorComp
 		return allModels[i].ModelID < allModels[j].ModelID
 	})
 
-	ms := &ModelSelectorComponent{
+	// Build PopupItems from model entries.
+	items := make([]PopupItem, len(allModels))
+	for i, m := range allModels {
+		items[i] = PopupItem{
+			Label:       m.ModelID,
+			Description: fmt.Sprintf("[%s]", m.Provider),
+			Active:      m.Provider+"/"+m.ModelID == currentModel,
+			Meta:        m,
+		}
+	}
+
+	popup := NewPopupList("Model Selector", items, width, height)
+	popup.Subtitle = "Only showing models with configured API keys"
+	popup.FilterFunc = func(query string, allItems []PopupItem) []PopupItem {
+		return filterModels(query, allItems)
+	}
+
+	return &ModelSelectorComponent{
+		popup:        popup,
 		allModels:    allModels,
-		filtered:     allModels,
 		currentModel: currentModel,
 		width:        width,
 		height:       height,
 		active:       true,
 	}
-
-	// Position cursor on the current model if found.
-	for i, m := range ms.filtered {
-		if m.Provider+"/"+m.ModelID == currentModel {
-			ms.cursor = i
-			break
-		}
-	}
-
-	return ms
 }
 
 // Init implements tea.Model.
@@ -111,177 +114,43 @@ func (ms *ModelSelectorComponent) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	case tea.WindowSizeMsg:
 		ms.width = msg.Width
 		ms.height = msg.Height
+		ms.popup.SetSize(msg.Width, msg.Height)
 		return ms, nil
 
 	case tea.KeyPressMsg:
-		switch {
-		case key.Matches(msg, key.NewBinding(key.WithKeys("up", "k"))):
-			if ms.cursor > 0 {
-				ms.cursor--
-			}
+		result := ms.popup.HandleKey(msg.String(), msg.Text)
 
-		case key.Matches(msg, key.NewBinding(key.WithKeys("down", "j"))):
-			if ms.cursor < len(ms.filtered)-1 {
-				ms.cursor++
+		if result.Selected != nil {
+			ms.active = false
+			entry := result.Selected.Meta.(ModelEntry)
+			modelStr := entry.Provider + "/" + entry.ModelID
+			return ms, func() tea.Msg {
+				return ModelSelectedMsg{ModelString: modelStr}
 			}
-
-		case key.Matches(msg, key.NewBinding(key.WithKeys("pgup"))):
-			ms.cursor -= ms.visibleHeight()
-			if ms.cursor < 0 {
-				ms.cursor = 0
-			}
-
-		case key.Matches(msg, key.NewBinding(key.WithKeys("pgdown"))):
-			ms.cursor += ms.visibleHeight()
-			if ms.cursor >= len(ms.filtered) {
-				ms.cursor = len(ms.filtered) - 1
-			}
-			if ms.cursor < 0 {
-				ms.cursor = 0
-			}
-
-		case key.Matches(msg, key.NewBinding(key.WithKeys("home"))):
-			ms.cursor = 0
-
-		case key.Matches(msg, key.NewBinding(key.WithKeys("end"))):
-			ms.cursor = max(len(ms.filtered)-1, 0)
-
-		case key.Matches(msg, key.NewBinding(key.WithKeys("enter"))):
-			if ms.cursor < len(ms.filtered) {
-				entry := ms.filtered[ms.cursor]
-				ms.active = false
-				return ms, func() tea.Msg {
-					return ModelSelectedMsg{
-						ModelString: entry.Provider + "/" + entry.ModelID,
-					}
-				}
-			}
-
-		case key.Matches(msg, key.NewBinding(key.WithKeys("esc"))):
-			if ms.search != "" {
-				ms.search = ""
-				ms.rebuildFiltered()
-			} else {
-				ms.active = false
-				return ms, func() tea.Msg {
-					return ModelSelectorCancelledMsg{}
-				}
-			}
-
-		default:
-			// Inline text search.
-			if msg.Text != "" && len(msg.Text) == 1 {
-				ch := msg.Text[0]
-				if ch >= 32 && ch < 127 {
-					ms.search += string(ch)
-					ms.rebuildFiltered()
-				}
-			}
-			if key.Matches(msg, key.NewBinding(key.WithKeys("backspace"))) && len(ms.search) > 0 {
-				ms.search = ms.search[:len(ms.search)-1]
-				ms.rebuildFiltered()
+		}
+		if result.Cancelled {
+			ms.active = false
+			return ms, func() tea.Msg {
+				return ModelSelectorCancelledMsg{}
 			}
 		}
 	}
 	return ms, nil
 }
 
-// View implements tea.Model.
+// View implements tea.Model — not used for overlay rendering.
+// Use RenderOverlay for the centered overlay approach.
 func (ms *ModelSelectorComponent) View() tea.View {
-	theme := GetTheme()
+	// Fallback full-screen rendering (unused when rendered as overlay).
+	v := tea.NewView(ms.popup.RenderCentered(ms.width, ms.height))
+	v.AltScreen = true
+	return v
+}
 
-	headerStyle := lipgloss.NewStyle().
-		Bold(true).
-		Foreground(theme.Accent).
-		PaddingLeft(2)
-
-	helpStyle := lipgloss.NewStyle().
-		Foreground(theme.Muted).
-		PaddingLeft(2)
-
-	infoStyle := lipgloss.NewStyle().
-		Foreground(theme.Warning).
-		PaddingLeft(2)
-
-	var b strings.Builder
-
-	// Header.
-	b.WriteString(headerStyle.Render("Model Selector"))
-	b.WriteString("\n")
-	// Adapt help text to terminal width.
-	if ms.width >= 56 {
-		b.WriteString(helpStyle.Render("↑/↓: move  enter: select  esc: cancel  type to filter"))
-	} else if ms.width >= 35 {
-		b.WriteString(helpStyle.Render("↑↓ move  ↵ select  esc  type"))
-	} else {
-		b.WriteString(helpStyle.Render("↑↓ ↵ esc"))
-	}
-	b.WriteString("\n")
-	if ms.width >= 48 {
-		b.WriteString(infoStyle.Render("Only showing models with configured API keys"))
-	} else {
-		b.WriteString(infoStyle.Render("Models with API keys"))
-	}
-	b.WriteString("\n")
-
-	// Search input.
-	searchStyle := lipgloss.NewStyle().Foreground(theme.Info).PaddingLeft(2)
-	if ms.search != "" {
-		b.WriteString(searchStyle.Render(fmt.Sprintf("> %s", ms.search)))
-	} else {
-		b.WriteString(searchStyle.Render("> "))
-	}
-	b.WriteString("\n")
-
-	b.WriteString(lipgloss.NewStyle().Foreground(theme.Muted).Render(strings.Repeat("─", ms.width)))
-	b.WriteString("\n")
-
-	if len(ms.filtered) == 0 {
-		emptyStyle := lipgloss.NewStyle().Foreground(theme.Muted).PaddingLeft(2)
-		if ms.search != "" {
-			b.WriteString(emptyStyle.Render("No models matching \"" + ms.search + "\""))
-		} else {
-			b.WriteString(emptyStyle.Render("No models available (check API keys)"))
-		}
-		b.WriteString("\n")
-	} else {
-		// Visible window.
-		visH := ms.visibleHeight()
-		startIdx := 0
-		if ms.cursor >= visH {
-			startIdx = ms.cursor - visH + 1
-		}
-		endIdx := min(startIdx+visH, len(ms.filtered))
-
-		for i := startIdx; i < endIdx; i++ {
-			entry := ms.filtered[i]
-			line := ms.renderEntry(entry, i == ms.cursor)
-			b.WriteString(line)
-			b.WriteString("\n")
-		}
-	}
-
-	// Footer.
-	b.WriteString(lipgloss.NewStyle().Foreground(theme.Muted).Render(strings.Repeat("─", ms.width)))
-	b.WriteString("\n")
-
-	footerParts := []string{
-		fmt.Sprintf("(%d/%d)", ms.cursor+1, len(ms.filtered)),
-	}
-	if ms.cursor < len(ms.filtered) {
-		entry := ms.filtered[ms.cursor]
-		if entry.Name != "" {
-			footerParts = append(footerParts, fmt.Sprintf("Model Name: %s", entry.Name))
-		}
-		if entry.ContextLimit > 0 {
-			footerParts = append(footerParts, fmt.Sprintf("Context: %dK", entry.ContextLimit/1000))
-		}
-	}
-
-	footerStyle := lipgloss.NewStyle().Foreground(theme.Muted).PaddingLeft(2)
-	b.WriteString(footerStyle.Render(strings.Join(footerParts, "  ")))
-
-	return tea.NewView(b.String())
+// RenderOverlay returns the popup as a centered overlay string, ready to be
+// composited on top of the main content via overlayContent().
+func (ms *ModelSelectorComponent) RenderOverlay(termWidth, termHeight int) string {
+	return ms.popup.RenderCentered(termWidth, termHeight)
 }
 
 // IsActive returns whether the selector is still accepting input.
@@ -289,56 +158,50 @@ func (ms *ModelSelectorComponent) IsActive() bool {
 	return ms.active
 }
 
-// --- Internal helpers ---
+// --- Model-specific fuzzy filter ---
 
-func (ms *ModelSelectorComponent) visibleHeight() int {
-	// Reserve: header(1) + help(1) + info(1) + search(1) + separator(1) + footer(2) = 7.
-	// Minimum 3 entries so the selector is still usable on short terminals.
-	return max(ms.height-7, 3)
-}
+// filterModels scores and filters PopupItems whose Meta is a ModelEntry.
+func filterModels(query string, items []PopupItem) []PopupItem {
+	if query == "" {
+		return items
+	}
+	q := strings.ToLower(query)
 
-func (ms *ModelSelectorComponent) rebuildFiltered() {
-	if ms.search == "" {
-		ms.filtered = ms.allModels
-	} else {
-		query := strings.ToLower(ms.search)
-		ms.filtered = ms.filtered[:0]
+	type scored struct {
+		item  PopupItem
+		score int
+	}
+	var matches []scored
 
-		type scored struct {
-			entry ModelEntry
-			score int
+	for _, item := range items {
+		entry, ok := item.Meta.(ModelEntry)
+		if !ok {
+			continue
 		}
-		var matches []scored
-
-		for _, entry := range ms.allModels {
-			s := ms.fuzzyScoreModel(query, entry)
-			if s > 0 {
-				matches = append(matches, scored{entry: entry, score: s})
-			}
-		}
-
-		// Sort by score descending, then alphabetically.
-		sort.Slice(matches, func(i, j int) bool {
-			if matches[i].score != matches[j].score {
-				return matches[i].score > matches[j].score
-			}
-			return matches[i].entry.ModelID < matches[j].entry.ModelID
-		})
-
-		ms.filtered = make([]ModelEntry, len(matches))
-		for i, m := range matches {
-			ms.filtered[i] = m.entry
+		s := fuzzyScoreModelEntry(q, entry)
+		if s > 0 {
+			matches = append(matches, scored{item: item, score: s})
 		}
 	}
 
-	// Clamp cursor.
-	if ms.cursor >= len(ms.filtered) {
-		ms.cursor = max(len(ms.filtered)-1, 0)
+	sort.Slice(matches, func(i, j int) bool {
+		if matches[i].score != matches[j].score {
+			return matches[i].score > matches[j].score
+		}
+		a := matches[i].item.Meta.(ModelEntry)
+		b := matches[j].item.Meta.(ModelEntry)
+		return a.ModelID < b.ModelID
+	})
+
+	result := make([]PopupItem, len(matches))
+	for i, m := range matches {
+		result[i] = m.item
 	}
+	return result
 }
 
-// fuzzyScoreModel scores a model entry against the search query.
-func (ms *ModelSelectorComponent) fuzzyScoreModel(query string, entry ModelEntry) int {
+// fuzzyScoreModelEntry scores a model entry against the search query.
+func fuzzyScoreModelEntry(query string, entry ModelEntry) int {
 	modelID := strings.ToLower(entry.ModelID)
 	provider := strings.ToLower(entry.Provider)
 	name := strings.ToLower(entry.Name)
@@ -391,67 +254,3 @@ func (ms *ModelSelectorComponent) fuzzyScoreModel(query string, entry ModelEntry
 
 	return 0
 }
-
-func (ms *ModelSelectorComponent) renderEntry(entry ModelEntry, isCursor bool) string {
-	theme := GetTheme()
-	modelStr := entry.ModelID
-	providerStr := fmt.Sprintf("[%s]", entry.Provider)
-
-	// Cursor indicator.
-	var cursor string
-	if isCursor {
-		cursor = lipgloss.NewStyle().Foreground(theme.Accent).Render("-> ")
-	} else {
-		cursor = "   "
-	}
-
-	// Active model checkmark.
-	var active string
-	activeWidth := 0
-	if entry.Provider+"/"+entry.ModelID == ms.currentModel {
-		active = lipgloss.NewStyle().Foreground(theme.Success).Render(" \u2713")
-		activeWidth = 2 // " ✓"
-	}
-
-	// Truncate model ID and provider tag to fit terminal width.
-	// Layout: cursor(3) + model + " " + provider + active.
-	// Use rune length for display-width accuracy (the "…" suffix is 1 rune / 1 column).
-	const cursorWidth = 3
-	available := max(ms.width-cursorWidth-activeWidth-1, 10) // 1 for space between model and provider
-	provDisplayLen := len([]rune(providerStr))
-	modelDisplayLen := len([]rune(modelStr))
-
-	if modelDisplayLen+1+provDisplayLen > available {
-		// Prioritize model name — truncate it, but keep provider visible.
-		maxModel := max(available-provDisplayLen-1, 6)
-		if maxModel < modelDisplayLen {
-			if maxModel > 3 {
-				runes := []rune(modelStr)
-				modelStr = string(runes[:maxModel-1]) + "…"
-			} else {
-				runes := []rune(modelStr)
-				modelStr = string(runes[:maxModel])
-			}
-		}
-		// If provider itself is too long, drop it.
-		modelDisplayLen = len([]rune(modelStr))
-		if modelDisplayLen+1+provDisplayLen > available {
-			providerStr = ""
-		}
-	}
-
-	// Style the model ID.
-	modelStyle := lipgloss.NewStyle().Foreground(theme.Text)
-	if isCursor {
-		modelStyle = modelStyle.Bold(true).Foreground(theme.Accent)
-	}
-
-	// Style the provider tag.
-	providerStyle := lipgloss.NewStyle().Foreground(theme.Muted)
-
-	result := cursor + modelStyle.Render(modelStr)
-	if providerStr != "" {
-		result += " " + providerStyle.Render(providerStr)
-	}
-	return result + active
-}

internal/ui/model_test.go

@@ -5,9 +5,10 @@ import (
 	"testing"
 
 	tea "charm.land/bubbletea/v2"
-	"charm.land/fantasy"
 	"github.com/mark3labs/kit/internal/app"
 	"github.com/mark3labs/kit/internal/session"
+	"github.com/mark3labs/kit/internal/ui/core"
+	kit "github.com/mark3labs/kit/pkg/kit"
 )
 
 // --------------------------------------------------------------------------
@@ -46,6 +47,10 @@ func (s *stubAppController) ClearMessages() {
 	s.clearMsgCalled++
 }
 
+func (s *stubAppController) ReloadMessagesFromTree() {
+	// no-op in tests
+}
+
 func (s *stubAppController) CompactConversation(_ string) error {
 	return nil
 }
@@ -66,7 +71,7 @@ func (s *stubAppController) AddContextMessage(_ string) {
 	// no-op in tests
 }
 
-func (s *stubAppController) RunWithFiles(prompt string, _ []fantasy.FilePart) int {
+func (s *stubAppController) RunWithFiles(prompt string, _ []kit.LLMFilePart) int {
 	s.runCalls = append(s.runCalls, prompt)
 	return s.queueLen
 }
@@ -76,6 +81,11 @@ func (s *stubAppController) Steer(prompt string) int {
 	return s.queueLen
 }
 
+func (s *stubAppController) SteerWithFiles(prompt string, _ []kit.LLMFilePart) int {
+	s.runCalls = append(s.runCalls, prompt)
+	return s.queueLen
+}
+
 // --------------------------------------------------------------------------
 // Stub child components
 // --------------------------------------------------------------------------
@@ -83,7 +93,6 @@ func (s *stubAppController) Steer(prompt string) int {
 // stubStreamComponent satisfies streamComponentIface without rendering anything.
 type stubStreamComponent struct {
 	resetCalled     int
-	height          int
 	lastMsg         tea.Msg
 	renderedContent string // returned by GetRenderedContent
 }
@@ -95,11 +104,11 @@ func (s *stubStreamComponent) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 }
 func (s *stubStreamComponent) View() tea.View             { return tea.NewView("") }
 func (s *stubStreamComponent) Reset()                     { s.resetCalled++; s.renderedContent = "" }
-func (s *stubStreamComponent) SetHeight(h int)            { s.height = h }
 func (s *stubStreamComponent) GetRenderedContent() string { return s.renderedContent }
 func (s *stubStreamComponent) SpinnerView() string        { return "" }
 func (s *stubStreamComponent) SetThinkingVisible(bool)    {}
 func (s *stubStreamComponent) HasReasoning() bool         { return false }
+func (s *stubStreamComponent) UpdateTheme()               {}
 
 // stubInputComponent satisfies inputComponentIface without rendering anything.
 type stubInputComponent struct {
@@ -126,11 +135,12 @@ func newTestAppModel(ctrl AppController) (*AppModel, *stubStreamComponent, *stub
 		stream:                stream,
 		input:                 input,
 		renderer:              newMessageRenderer(80, false),
-		compactMode:           false,
 		modelName:             "test-model",
 		width:                 80,
 		height:                24,
 		streamingBashMaxLines: 50, // Initialize buffer cap like NewAppModel does
+		scrollList:            NewScrollList(80, 20),
+		messages:              []MessageItem{},
 	}
 	return m, stream, input
 }
@@ -142,7 +152,11 @@ func newTestAppModel(ctrl AppController) (*AppModel, *stubStreamComponent, *stub
 // sendMsg calls m.Update once with the given message and returns the updated model.
 func sendMsg(m *AppModel, msg tea.Msg) *AppModel {
 	updated, _ := m.Update(msg)
-	return updated.(*AppModel)
+	result := updated.(*AppModel)
+	// Simulate BubbleTea's frame cycle: View() is called after every Update().
+	// This flushes any pending layoutDirty work (e.g. distributeHeight).
+	_ = result.View()
+	return result
 }
 
 // --------------------------------------------------------------------------
@@ -159,7 +173,7 @@ func TestStateTransition_InputToWorking(t *testing.T) {
 		t.Fatalf("expected stateInput, got %v", m.state)
 	}
 
-	m = sendMsg(m, submitMsg{Text: "hello"})
+	m = sendMsg(m, core.SubmitMsg{Text: "hello"})
 
 	if m.state != stateWorking {
 		t.Fatalf("expected stateWorking after submitMsg, got %v", m.state)
@@ -347,7 +361,7 @@ func TestESCCancel_timerExpiry(t *testing.T) {
 	m.state = stateWorking
 	m.canceling = true
 
-	m = sendMsg(m, cancelTimerExpiredMsg{})
+	m = sendMsg(m, core.CancelTimerExpiredMsg{})
 
 	if m.canceling {
 		t.Fatal("expected canceling=false after timer expiry")
@@ -400,7 +414,7 @@ func TestQueuedMessages_storedOnQueuedSubmit(t *testing.T) {
 	m, _, _ := newTestAppModel(ctrl)
 	m.state = stateWorking
 
-	_, cmd := m.Update(submitMsg{Text: "queued prompt"})
+	_, cmd := m.Update(core.SubmitMsg{Text: "queued prompt"})
 
 	if len(m.queuedMessages) != 1 {
 		t.Fatalf("expected 1 queued message, got %d", len(m.queuedMessages))
@@ -408,7 +422,7 @@ func TestQueuedMessages_storedOnQueuedSubmit(t *testing.T) {
 	if m.queuedMessages[0] != "queued prompt" {
 		t.Fatalf("expected queued message text 'queued prompt', got %q", m.queuedMessages[0])
 	}
-	// Should NOT produce a tea.Println cmd (message is anchored, not in scrollback).
+	// Should NOT flush (message is anchored in ScrollList).
 	if cmd != nil {
 		t.Fatal("expected nil cmd for queued submit (message should not print to scrollback)")
 	}
@@ -498,19 +512,19 @@ func TestWindowResize_propagatesToStream(t *testing.T) {
 // sets the stream height after a resize.
 func TestWindowResize_distributeHeight(t *testing.T) {
 	ctrl := &stubAppController{}
-	m, stream, _ := newTestAppModel(ctrl)
+	m, _, _ := newTestAppModel(ctrl)
 
-	// With height=30, stream height = 30 - 1 (separator) - 9 (input) - 1 (statusBar) = 19
+	// With height=30, scroll height = 30 - 1 (separator) - 9 (input) - 1 (statusBar) = 19
 	m = sendMsg(m, tea.WindowSizeMsg{Width: 80, Height: 30})
 	_ = m
 
-	if stream.height != 19 {
-		t.Fatalf("expected stream height=19, got %d", stream.height)
+	if m.scrollList.height != 19 {
+		t.Fatalf("expected scroll list height=19, got %d", m.scrollList.height)
 	}
 }
 
 // --------------------------------------------------------------------------
-// tea.Println on step complete
+// Step complete behavior
 // --------------------------------------------------------------------------
 
 // TestStepComplete_preservesStreamContent verifies that StepCompleteEvent
@@ -543,65 +557,87 @@ func TestStepComplete_noStreamContent_noCmd(t *testing.T) {
 	}
 }
 
-// TestSubmitMsg_printsUserMessage verifies that submitMsg produces a tea.Println
-// cmd for the user message.
+// TestSubmitMsg_printsUserMessage verifies that submitMsg adds the user message
+// to the ScrollList messages and triggers a layout update.
 func TestSubmitMsg_printsUserMessage(t *testing.T) {
 	ctrl := &stubAppController{}
 	m, _, _ := newTestAppModel(ctrl)
 
-	_, cmd := m.Update(submitMsg{Text: "user query"})
+	m = sendMsg(m, core.SubmitMsg{Text: "user query"})
 
-	if cmd == nil {
-		t.Fatal("expected non-nil cmd (tea.Println) for user message on submitMsg")
+	// In alt screen mode, user messages are added to the in-memory ScrollList
+	// rather than printed separately. Verify the message was added.
+	found := false
+	for _, msg := range m.messages {
+		if tm, ok := msg.(*TextMessageItem); ok && tm.role == "user" && tm.content == "user query" {
+			found = true
+			break
+		}
+	}
+	if !found {
+		t.Fatal("expected user message 'user query' in ScrollList messages")
 	}
 }
 
-// TestToolCallStarted_flushesOnly verifies that ToolCallStartedEvent flushes
-// accumulated stream content but does NOT print a tool call block (the unified
-// block is printed later on ToolResultEvent).
+// TestToolCallStarted_flushesOnly verifies that ToolCallStartedEvent marks
+// any active StreamingMessageItem as complete and resets the stream.
 func TestToolCallStarted_flushesOnly(t *testing.T) {
 	ctrl := &stubAppController{}
 	m, stream, _ := newTestAppModel(ctrl)
 	m.state = stateWorking
 
-	// With no stream content, flush returns nil → cmd should be nil.
-	_, cmd := m.Update(app.ToolCallStartedEvent{
+	// With no stream content, nothing should change.
+	initialCount := len(m.messages)
+	m = sendMsg(m, app.ToolCallStartedEvent{
 		ToolName: "bash",
 		ToolArgs: `{"cmd":"ls"}`,
 	})
 
-	if cmd != nil {
-		t.Fatal("expected nil cmd on ToolCallStartedEvent with no stream content")
+	if len(m.messages) != initialCount {
+		t.Fatal("expected no new messages on ToolCallStartedEvent with no stream content")
 	}
 
-	// With stream content, flush returns tea.Println → cmd should be non-nil.
+	// Simulate a StreamingMessageItem already in messages (as if appendStreamingChunk was called)
+	// plus the stream component having rendered content.
+	streamItem := NewStreamingMessageItem("stream-1", "assistant", "test-model")
+	streamItem.AppendChunk("partial text")
+	m.messages = append(m.messages, streamItem)
 	stream.renderedContent = "partial text"
-	_, cmd = m.Update(app.ToolCallStartedEvent{
+
+	_ = sendMsg(m, app.ToolCallStartedEvent{
 		ToolName: "bash",
 		ToolArgs: `{"cmd":"ls"}`,
 	})
 
-	if cmd == nil {
-		t.Fatal("expected non-nil cmd on ToolCallStartedEvent with stream content to flush")
+	// The StreamingMessageItem should have been marked complete.
+	if streamItem.streaming {
+		t.Fatal("expected StreamingMessageItem to be marked complete after ToolCallStartedEvent")
+	}
+	// Stream should have been reset.
+	if stream.resetCalled == 0 {
+		t.Fatal("expected stream.Reset() to be called")
 	}
 }
 
-// TestToolResult_printsAndStartsSpinner verifies that ToolResultEvent produces
-// a non-nil cmd and the stream receives a SpinnerEvent.
+// TestToolResult_printsAndStartsSpinner verifies that ToolResultEvent adds
+// the tool result to the ScrollList and the stream receives a SpinnerEvent.
 func TestToolResult_printsAndStartsSpinner(t *testing.T) {
 	ctrl := &stubAppController{}
 	m, stream, _ := newTestAppModel(ctrl)
 	m.state = stateWorking
 
-	_, cmd := m.Update(app.ToolResultEvent{
+	initialCount := len(m.messages)
+
+	m = sendMsg(m, app.ToolResultEvent{
 		ToolName: "bash",
 		ToolArgs: "{}",
 		Result:   "output",
 		IsError:  false,
 	})
 
-	if cmd == nil {
-		t.Fatal("expected non-nil cmd on ToolResultEvent")
+	// Tool result should have been added to ScrollList messages.
+	if len(m.messages) <= initialCount {
+		t.Fatal("expected tool result message added to ScrollList")
 	}
 	// Stream should have received a SpinnerEvent to start spinner for next LLM call.
 	if stream.lastMsg == nil {
@@ -613,7 +649,7 @@ func TestToolResult_printsAndStartsSpinner(t *testing.T) {
 }
 
 // TestToolOutputEvent_accumulatesBashOutput verifies that ToolOutputEvent
-// accumulates stdout and stderr lines into the streaming bash output buffers.
+// accumulates stdout and stderr lines into a StreamingBashOutputItem in the ScrollList.
 func TestToolOutputEvent_accumulatesBashOutput(t *testing.T) {
 	ctrl := &stubAppController{}
 	m, _, _ := newTestAppModel(ctrl)
@@ -627,11 +663,23 @@ func TestToolOutputEvent_accumulatesBashOutput(t *testing.T) {
 		IsStderr:   false,
 	})
 
-	if len(m.streamingBashOutput) != 1 || m.streamingBashOutput[0] != "line one\n" {
-		t.Fatalf("expected streamingBashOutput=['line one\\n'], got %v", m.streamingBashOutput)
+	// Should have created a StreamingBashOutputItem in messages.
+	var bashItem *StreamingBashOutputItem
+	for _, msg := range m.messages {
+		if item, ok := msg.(*StreamingBashOutputItem); ok {
+			bashItem = item
+			break
+		}
 	}
-	if len(m.streamingBashStderr) != 0 {
-		t.Fatalf("expected empty streamingBashStderr, got %v", m.streamingBashStderr)
+	if bashItem == nil {
+		t.Fatal("expected StreamingBashOutputItem in messages after ToolOutputEvent")
+		return
+	}
+	if len(bashItem.stdoutLines) != 1 || bashItem.stdoutLines[0] != "line one\n" {
+		t.Fatalf("expected stdout=['line one\\n'], got %v", bashItem.stdoutLines)
+	}
+	if len(bashItem.stderrLines) != 0 {
+		t.Fatalf("expected empty stderr, got %v", bashItem.stderrLines)
 	}
 
 	// Send another stdout chunk.
@@ -642,8 +690,15 @@ func TestToolOutputEvent_accumulatesBashOutput(t *testing.T) {
 		IsStderr:   false,
 	})
 
-	if len(m.streamingBashOutput) != 2 {
-		t.Fatalf("expected 2 stdout lines, got %d", len(m.streamingBashOutput))
+	// Re-find the bash item (same item, updated)
+	bashItem = nil
+	for _, msg := range m.messages {
+		if item, ok := msg.(*StreamingBashOutputItem); ok {
+			bashItem = item
+		}
+	}
+	if bashItem == nil || len(bashItem.stdoutLines) != 2 {
+		t.Fatalf("expected 2 stdout lines, got %d", len(bashItem.stdoutLines))
 	}
 
 	// Send stderr chunk.
@@ -654,11 +709,17 @@ func TestToolOutputEvent_accumulatesBashOutput(t *testing.T) {
 		IsStderr:   true,
 	})
 
-	if len(m.streamingBashStderr) != 1 {
-		t.Fatalf("expected 1 stderr line, got %d", len(m.streamingBashStderr))
+	bashItem = nil
+	for _, msg := range m.messages {
+		if item, ok := msg.(*StreamingBashOutputItem); ok {
+			bashItem = item
+		}
 	}
-	if m.streamingBashStderr[0] != "error: something failed\n" {
-		t.Fatalf("expected stderr 'error: something failed\\n', got %q", m.streamingBashStderr[0])
+	if bashItem == nil || len(bashItem.stderrLines) != 1 {
+		t.Fatalf("expected 1 stderr line, got %d", len(bashItem.stderrLines))
+	}
+	if bashItem.stderrLines[0] != "error: something failed\n" {
+		t.Fatalf("expected stderr 'error: something failed\\n', got %q", bashItem.stderrLines[0])
 	}
 }
 
@@ -740,16 +801,19 @@ func TestToolCallStarted_nonBashTool_doesNotSetCommand(t *testing.T) {
 }
 
 // TestStepError_printCmd verifies that StepErrorEvent with a non-nil error
-// produces a non-nil cmd (the tea.Println call for the error message).
+// adds an error message to the ScrollList.
 func TestStepError_printCmd(t *testing.T) {
 	ctrl := &stubAppController{}
 	m, _, _ := newTestAppModel(ctrl)
 	m.state = stateWorking
 
-	_, cmd := m.Update(app.StepErrorEvent{Err: errors.New("agent failed")})
+	initialCount := len(m.messages)
 
-	if cmd == nil {
-		t.Fatal("expected non-nil cmd (tea.Println) on StepErrorEvent with error")
+	m = sendMsg(m, app.StepErrorEvent{Err: errors.New("agent failed")})
+
+	// Error should have been added to ScrollList messages.
+	if len(m.messages) <= initialCount {
+		t.Fatal("expected error message added to ScrollList on StepErrorEvent")
 	}
 }
 
@@ -819,7 +883,7 @@ func TestSubmit_duringWorking_stays(t *testing.T) {
 	m, _, _ := newTestAppModel(ctrl)
 	m.state = stateWorking
 
-	m = sendMsg(m, submitMsg{Text: "queued prompt"})
+	m = sendMsg(m, core.SubmitMsg{Text: "queued prompt"})
 
 	if m.state != stateWorking {
 		t.Fatalf("expected stateWorking to persist after submitMsg during working, got %v", m.state)

internal/ui/overlay.go

@@ -6,6 +6,8 @@ import (
 
 	tea "charm.land/bubbletea/v2"
 	"charm.land/lipgloss/v2"
+
+	"github.com/mark3labs/kit/internal/ui/style"
 )
 
 // ---------------------------------------------------------------------------
@@ -133,7 +135,7 @@ func (o *overlayDialog) handleKey(msg tea.KeyPressMsg) (*overlayResult, tea.Cmd)
 // composition. The dialog is a bordered box centered (or anchored)
 // horizontally within the terminal width.
 func (o *overlayDialog) Render() string {
-	theme := GetTheme()
+	theme := style.GetTheme()
 
 	// Calculate dialog dimensions, clamped to terminal bounds.
 	termW := max(o.width, 10)
@@ -157,7 +159,7 @@ func (o *overlayDialog) Render() string {
 	// Render body text (potentially as markdown).
 	bodyText := o.content
 	if o.markdown {
-		bodyText = toMarkdown(bodyText, innerWidth)
+		bodyText = style.ToMarkdown(bodyText, innerWidth)
 	}
 	bodyText = strings.TrimRight(bodyText, "\n")
 

internal/ui/popup_list.go

@@ -0,0 +1,501 @@
+package ui
+
+import (
+	"fmt"
+	"strings"
+
+	"charm.land/lipgloss/v2"
+
+	"github.com/mark3labs/kit/internal/ui/style"
+)
+
+// PopupItem represents a single entry in a PopupList. The component renders
+// Label as the primary text and Description as secondary text to its right.
+// The Active flag renders a checkmark to indicate the currently-active item
+// (e.g. the current model). Meta is opaque caller data returned on selection.
+type PopupItem struct {
+	Label       string // primary display text
+	Description string // secondary text (shown right of label)
+	Active      bool   // true → render checkmark indicator
+	Meta        any    // opaque data returned on selection
+}
+
+// PopupList is a generic, themed, scrollable fuzzy-find popup list. It is
+// rendered as a centered overlay on top of the normal TUI layout and can be
+// reused by any feature that needs a selection popup (slash commands, model
+// selector, session picker, extension-provided lists, etc.).
+//
+// The caller is responsible for:
+//   - Building the initial item list
+//   - Providing a fuzzy-filter callback (or nil for substring matching)
+//   - Handling the result when the user selects or cancels
+//
+// Navigation: up/down to move, enter to select, esc to cancel, type to filter.
+type PopupList struct {
+	// Title shown at the top of the popup.
+	Title string
+	// Subtitle shown below the title (dimmed).
+	Subtitle string
+	// FooterHint overrides the default keyboard-hint footer.
+	FooterHint string
+
+	allItems []PopupItem // full unfiltered list
+	filtered []PopupItem // subset matching the current search
+	cursor   int
+	search   string
+
+	// FilterFunc is called with (query, allItems) and should return the
+	// filtered+scored subset. When nil, a default substring match is used.
+	FilterFunc func(query string, items []PopupItem) []PopupItem
+
+	width      int
+	height     int
+	maxVisible int // max items visible at once (0 = auto from height)
+	showSearch bool
+}
+
+// PopupResult is returned by HandleKey to tell the caller what happened.
+type PopupResult struct {
+	// Selected is non-nil when the user pressed Enter on an item.
+	Selected *PopupItem
+	// Cancelled is true when the user pressed Esc with no search text.
+	Cancelled bool
+	// Changed is true when the search or cursor moved (caller should re-render).
+	Changed bool
+}
+
+// NewPopupList creates a new popup list with the given items and dimensions.
+func NewPopupList(title string, items []PopupItem, width, height int) *PopupList {
+	p := &PopupList{
+		Title:      title,
+		allItems:   items,
+		filtered:   items,
+		width:      width,
+		height:     height,
+		showSearch: true,
+	}
+	// Position cursor on the active item if one exists.
+	for i, item := range p.filtered {
+		if item.Active {
+			p.cursor = i
+			break
+		}
+	}
+	return p
+}
+
+// SetSize updates the popup dimensions (e.g. on window resize).
+func (p *PopupList) SetSize(width, height int) {
+	p.width = width
+	p.height = height
+}
+
+// visibleCount returns the number of items visible at once.
+func (p *PopupList) visibleCount() int {
+	if p.maxVisible > 0 {
+		return p.maxVisible
+	}
+	// Reserve: title(1) + subtitle(1) + search(1) + separator(1) + footer(2) + border(2) + padding(2) = 10
+	overhead := 8
+	if p.Subtitle != "" {
+		overhead++
+	}
+	if p.showSearch {
+		overhead += 2 // search line + separator
+	}
+	return max(p.height/2-overhead, 3)
+}
+
+// HandleKey processes a single key event and returns the result. The caller
+// should inspect PopupResult to decide whether to re-render, close the popup,
+// or act on a selection.
+//
+// keyName is the Bubble Tea key string (e.g. "up", "down", "enter", "esc").
+// keyText is the printable text for character keys (e.g. "a", "1").
+func (p *PopupList) HandleKey(keyName, keyText string) PopupResult {
+	switch keyName {
+	case "up":
+		if p.cursor > 0 {
+			p.cursor--
+			return PopupResult{Changed: true}
+		}
+		return PopupResult{}
+
+	case "down":
+		if p.cursor < len(p.filtered)-1 {
+			p.cursor++
+			return PopupResult{Changed: true}
+		}
+		return PopupResult{}
+
+	case "pgup":
+		p.cursor -= p.visibleCount()
+		if p.cursor < 0 {
+			p.cursor = 0
+		}
+		return PopupResult{Changed: true}
+
+	case "pgdown":
+		p.cursor += p.visibleCount()
+		if p.cursor >= len(p.filtered) {
+			p.cursor = max(len(p.filtered)-1, 0)
+		}
+		return PopupResult{Changed: true}
+
+	case "home":
+		p.cursor = 0
+		return PopupResult{Changed: true}
+
+	case "end":
+		p.cursor = max(len(p.filtered)-1, 0)
+		return PopupResult{Changed: true}
+
+	case "enter":
+		if p.cursor < len(p.filtered) {
+			item := p.filtered[p.cursor]
+			return PopupResult{Selected: &item}
+		}
+		return PopupResult{}
+
+	case "esc":
+		if p.search != "" {
+			p.search = ""
+			p.rebuildFiltered()
+			return PopupResult{Changed: true}
+		}
+		return PopupResult{Cancelled: true}
+
+	case "backspace":
+		if len(p.search) > 0 {
+			p.search = p.search[:len(p.search)-1]
+			p.rebuildFiltered()
+			return PopupResult{Changed: true}
+		}
+		return PopupResult{}
+
+	default:
+		// Printable character → append to search.
+		if keyText != "" && len(keyText) == 1 {
+			ch := keyText[0]
+			if ch >= 32 && ch < 127 {
+				p.search += string(ch)
+				p.rebuildFiltered()
+				return PopupResult{Changed: true}
+			}
+		}
+		return PopupResult{}
+	}
+}
+
+// Render returns the styled popup content (bordered box) ready to be placed
+// as a centered overlay via lipgloss.Place + overlayContent.
+func (p *PopupList) Render() string {
+	theme := style.GetTheme()
+	popupWidth := max(min(p.width-4, 80), 20)
+	popupBg := theme.Background
+
+	popupStyle := lipgloss.NewStyle().
+		Border(lipgloss.RoundedBorder()).
+		BorderForeground(theme.Primary).
+		Background(popupBg).
+		Padding(1, 2).
+		Width(popupWidth).
+		MarginBottom(1)
+
+	// Inner content width: popup minus border (2) and horizontal padding (4).
+	innerWidth := max(popupWidth-6, 10)
+
+	var b strings.Builder
+
+	// Title.
+	titleStyle := lipgloss.NewStyle().
+		Bold(true).
+		Foreground(theme.Accent).
+		Background(popupBg).
+		Width(innerWidth)
+	b.WriteString(titleStyle.Render(p.Title))
+	b.WriteString("\n")
+
+	// Subtitle.
+	if p.Subtitle != "" {
+		subtitleStyle := lipgloss.NewStyle().
+			Foreground(theme.Muted).
+			Background(popupBg).
+			Width(innerWidth)
+		b.WriteString(subtitleStyle.Render(p.Subtitle))
+		b.WriteString("\n")
+	}
+
+	// Search input.
+	if p.showSearch {
+		searchStyle := lipgloss.NewStyle().
+			Foreground(theme.Info).
+			Background(popupBg).
+			Width(innerWidth)
+		if p.search != "" {
+			b.WriteString(searchStyle.Render(fmt.Sprintf("> %s", p.search)))
+		} else {
+			b.WriteString(searchStyle.Render("> "))
+		}
+		b.WriteString("\n")
+
+		// Separator.
+		sepStyle := lipgloss.NewStyle().
+			Foreground(theme.Muted).
+			Background(popupBg)
+		b.WriteString(sepStyle.Render(strings.Repeat("─", innerWidth)))
+		b.WriteString("\n")
+	}
+
+	// Item list.
+	normalItemBg := lipgloss.NewStyle().
+		Background(popupBg).
+		Foreground(theme.Text).
+		Width(innerWidth).
+		Padding(0, 1)
+
+	selectedItemBg := lipgloss.NewStyle().
+		Background(theme.Primary).
+		Foreground(theme.Background).
+		Width(innerWidth).
+		Padding(0, 1).
+		Bold(true)
+
+	scrollStyle := lipgloss.NewStyle().
+		Background(popupBg).
+		Foreground(theme.VeryMuted).
+		Width(innerWidth).
+		Padding(0, 1)
+
+	vis := p.visibleCount()
+	var items []string
+
+	if len(p.filtered) == 0 {
+		emptyStyle := lipgloss.NewStyle().
+			Foreground(theme.Muted).
+			Background(popupBg).
+			Width(innerWidth).
+			Padding(0, 1)
+		if p.search != "" {
+			items = append(items, emptyStyle.Render("No matches for \""+p.search+"\""))
+		} else {
+			items = append(items, emptyStyle.Render("No items"))
+		}
+	} else {
+		startIdx := 0
+		if p.cursor >= vis {
+			startIdx = p.cursor - vis + 1
+		}
+		endIdx := min(startIdx+vis, len(p.filtered))
+
+		if startIdx > 0 {
+			items = append(items, scrollStyle.Render("  ↑ more above"))
+		}
+
+		for i := startIdx; i < endIdx; i++ {
+			entry := p.filtered[i]
+			isCursor := i == p.cursor
+
+			itemStyle := normalItemBg
+			if isCursor {
+				itemStyle = selectedItemBg
+			}
+
+			// Build indicator.
+			var indicator string
+			if isCursor {
+				indicator = "> "
+			} else {
+				indicator = "  "
+			}
+
+			// Build content: indicator + label + description + active checkmark.
+			content := p.renderItemContent(indicator, entry, innerWidth, isCursor)
+			items = append(items, itemStyle.Render(content))
+		}
+
+		if endIdx < len(p.filtered) {
+			items = append(items, scrollStyle.Render("  ↓ more below"))
+		}
+	}
+
+	content := b.String() + strings.Join(items, "\n")
+
+	// Footer with count and keyboard hints.
+	var footerParts []string
+	footerParts = append(footerParts, fmt.Sprintf("(%d/%d)", p.cursor+1, len(p.filtered)))
+
+	footerHint := p.FooterHint
+	if footerHint == "" {
+		if innerWidth >= 50 {
+			footerHint = "↑↓ navigate • enter select • esc cancel • type to filter"
+		} else if innerWidth >= 30 {
+			footerHint = "↑↓ nav • ↵ select • esc"
+		} else {
+			footerHint = "↑↓ ↵ esc"
+		}
+	}
+	footerParts = append(footerParts, footerHint)
+
+	footer := lipgloss.NewStyle().
+		Background(popupBg).
+		Foreground(theme.VeryMuted).
+		Italic(true).
+		Render(strings.Join(footerParts, "  "))
+
+	return popupStyle.Render(content + "\n\n" + footer)
+}
+
+// RenderCentered returns the popup placed at the center of a termWidth×termHeight
+// canvas, ready to be composed with overlayContent().
+func (p *PopupList) RenderCentered(termWidth, termHeight int) string {
+	popupContent := p.Render()
+	return lipgloss.Place(
+		termWidth,
+		termHeight,
+		lipgloss.Center,
+		lipgloss.Center,
+		popupContent,
+	)
+}
+
+// IsSearching returns true when the search input is non-empty.
+func (p *PopupList) IsSearching() bool {
+	return p.search != ""
+}
+
+// SelectedItem returns the item under the cursor, or nil if the list is empty.
+func (p *PopupList) SelectedItem() *PopupItem {
+	if p.cursor < len(p.filtered) {
+		item := p.filtered[p.cursor]
+		return &item
+	}
+	return nil
+}
+
+// --- Internal helpers ---
+
+func (p *PopupList) rebuildFiltered() {
+	if p.FilterFunc != nil {
+		p.filtered = p.FilterFunc(p.search, p.allItems)
+	} else {
+		p.filtered = defaultFilter(p.search, p.allItems)
+	}
+	// Clamp cursor.
+	if p.cursor >= len(p.filtered) {
+		p.cursor = max(len(p.filtered)-1, 0)
+	}
+}
+
+// defaultFilter is a simple case-insensitive substring + fuzzy character match.
+func defaultFilter(query string, items []PopupItem) []PopupItem {
+	if query == "" {
+		return items
+	}
+	q := strings.ToLower(query)
+	type scored struct {
+		item  PopupItem
+		score int
+	}
+	var matches []scored
+	for _, item := range items {
+		label := strings.ToLower(item.Label)
+		desc := strings.ToLower(item.Description)
+
+		var s int
+		switch {
+		case label == q:
+			s = 1000
+		case strings.HasPrefix(label, q):
+			s = 800 - len(label) + len(q)
+		case strings.Contains(label, q):
+			s = 600
+		case strings.Contains(desc, q):
+			s = 400
+		default:
+			s = fuzzyCharacterMatch(q, label)
+		}
+		if s > 0 {
+			matches = append(matches, scored{item: item, score: s})
+		}
+	}
+
+	// Sort by score descending, then alphabetically by label.
+	for i := 0; i < len(matches)-1; i++ {
+		for j := i + 1; j < len(matches); j++ {
+			if matches[j].score > matches[i].score ||
+				(matches[j].score == matches[i].score && matches[j].item.Label < matches[i].item.Label) {
+				matches[i], matches[j] = matches[j], matches[i]
+			}
+		}
+	}
+
+	result := make([]PopupItem, len(matches))
+	for i, m := range matches {
+		result[i] = m.item
+	}
+	return result
+}
+
+// renderItemContent builds the display string for a single item row.
+func (p *PopupList) renderItemContent(indicator string, entry PopupItem, innerWidth int, isCursor bool) string {
+	theme := style.GetTheme()
+
+	// Reserve space: indicator(2) + potential checkmark(2)
+	activeWidth := 0
+	if entry.Active {
+		activeWidth = 2
+	}
+	available := max(innerWidth-2-activeWidth, 6) // 2 for indicator, already included
+
+	label := entry.Label
+	desc := entry.Description
+
+	if desc != "" {
+		// Two-column layout: label + description.
+		descWidth := len([]rune(desc)) + 1 // 1 space gap
+		labelMax := max(available-descWidth, available*2/3)
+		if len([]rune(label)) > labelMax && labelMax > 3 {
+			runes := []rune(label)
+			label = string(runes[:labelMax-1]) + "…"
+		}
+		labelDisplayLen := len([]rune(label))
+
+		// If label + desc don't fit, truncate or drop desc.
+		if labelDisplayLen+1+len([]rune(desc)) > available {
+			remaining := available - labelDisplayLen - 1
+			if remaining >= 4 {
+				runes := []rune(desc)
+				if len(runes) > remaining {
+					desc = string(runes[:remaining-1]) + "…"
+				}
+			} else {
+				desc = ""
+			}
+		}
+	} else {
+		// Single column: just the label.
+		if len([]rune(label)) > available && available > 3 {
+			runes := []rune(label)
+			label = string(runes[:available-1]) + "…"
+		}
+	}
+
+	result := indicator + label
+	if desc != "" {
+		descStyle := lipgloss.NewStyle().Foreground(theme.Muted)
+		if isCursor {
+			// When selected, use a dimmer foreground that still contrasts with Primary bg.
+			descStyle = lipgloss.NewStyle().Foreground(theme.Background)
+		}
+		result += " " + descStyle.Render(desc)
+	}
+	if entry.Active {
+		checkStyle := lipgloss.NewStyle().Foreground(theme.Success)
+		if isCursor {
+			checkStyle = lipgloss.NewStyle().Foreground(theme.Background)
+		}
+		result += checkStyle.Render(" ✓")
+	}
+	return result
+}

internal/ui/popup_list_test.go

@@ -0,0 +1,297 @@
+package ui
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestPopupList_NewPositionsCursorOnActiveItem(t *testing.T) {
+	items := []PopupItem{
+		{Label: "alpha"},
+		{Label: "beta"},
+		{Label: "gamma", Active: true},
+		{Label: "delta"},
+	}
+	p := NewPopupList("Test", items, 80, 40)
+
+	if p.cursor != 2 {
+		t.Errorf("expected cursor on active item (index 2), got %d", p.cursor)
+	}
+}
+
+func TestPopupList_HandleKey_Navigation(t *testing.T) {
+	items := []PopupItem{
+		{Label: "alpha"},
+		{Label: "beta"},
+		{Label: "gamma"},
+	}
+	p := NewPopupList("Test", items, 80, 40)
+
+	// Initial cursor at 0.
+	if p.cursor != 0 {
+		t.Fatalf("expected cursor 0, got %d", p.cursor)
+	}
+
+	// Down → 1.
+	res := p.HandleKey("down", "")
+	if !res.Changed || p.cursor != 1 {
+		t.Errorf("down: changed=%v cursor=%d", res.Changed, p.cursor)
+	}
+
+	// Down → 2.
+	p.HandleKey("down", "")
+	if p.cursor != 2 {
+		t.Errorf("expected cursor 2, got %d", p.cursor)
+	}
+
+	// Down at end → stays at 2.
+	res = p.HandleKey("down", "")
+	if p.cursor != 2 {
+		t.Errorf("down at end: expected cursor 2, got %d", p.cursor)
+	}
+
+	// Up → 1.
+	res = p.HandleKey("up", "")
+	if !res.Changed || p.cursor != 1 {
+		t.Errorf("up: changed=%v cursor=%d", res.Changed, p.cursor)
+	}
+
+	// Home → 0.
+	p.HandleKey("home", "")
+	if p.cursor != 0 {
+		t.Errorf("home: expected cursor 0, got %d", p.cursor)
+	}
+
+	// End → 2.
+	p.HandleKey("end", "")
+	if p.cursor != 2 {
+		t.Errorf("end: expected cursor 2, got %d", p.cursor)
+	}
+}
+
+func TestPopupList_HandleKey_Search(t *testing.T) {
+	items := []PopupItem{
+		{Label: "apple"},
+		{Label: "banana"},
+		{Label: "cherry"},
+	}
+	p := NewPopupList("Test", items, 80, 40)
+
+	// Type "an" → should filter to banana.
+	p.HandleKey("a", "a")
+	p.HandleKey("n", "n")
+
+	if !p.IsSearching() {
+		t.Error("expected IsSearching() to be true")
+	}
+	if len(p.filtered) == 0 {
+		t.Fatal("expected at least one filtered result")
+	}
+	// banana should match (contains "an").
+	found := false
+	for _, item := range p.filtered {
+		if item.Label == "banana" {
+			found = true
+			break
+		}
+	}
+	if !found {
+		t.Error("expected 'banana' in filtered results")
+	}
+
+	// Backspace removes last char.
+	p.HandleKey("backspace", "")
+	if p.search != "a" {
+		t.Errorf("expected search 'a' after backspace, got %q", p.search)
+	}
+
+	// Esc clears search.
+	res := p.HandleKey("esc", "")
+	if res.Cancelled {
+		t.Error("esc with search should clear search, not cancel")
+	}
+	if p.search != "" {
+		t.Errorf("expected empty search after esc, got %q", p.search)
+	}
+}
+
+func TestPopupList_HandleKey_SelectAndCancel(t *testing.T) {
+	items := []PopupItem{
+		{Label: "alpha", Meta: "first"},
+		{Label: "beta", Meta: "second"},
+	}
+	p := NewPopupList("Test", items, 80, 40)
+
+	// Select first item.
+	res := p.HandleKey("enter", "")
+	if res.Selected == nil {
+		t.Fatal("expected a selection on enter")
+	}
+	if res.Selected.Label != "alpha" {
+		t.Errorf("expected 'alpha', got %q", res.Selected.Label)
+	}
+	if res.Selected.Meta != "first" {
+		t.Errorf("expected meta 'first', got %v", res.Selected.Meta)
+	}
+
+	// Cancel with esc (no search text).
+	p2 := NewPopupList("Test", items, 80, 40)
+	res = p2.HandleKey("esc", "")
+	if !res.Cancelled {
+		t.Error("expected Cancelled on esc with no search")
+	}
+}
+
+func TestPopupList_DefaultFilter(t *testing.T) {
+	items := []PopupItem{
+		{Label: "foo-bar"},
+		{Label: "baz-qux"},
+		{Label: "foobar"},
+	}
+
+	// Exact prefix.
+	result := defaultFilter("foo", items)
+	if len(result) < 2 {
+		t.Fatalf("expected at least 2 matches for 'foo', got %d", len(result))
+	}
+	// "foobar" should rank higher (shorter match) or equal to "foo-bar".
+	if result[0].Label != "foobar" && result[1].Label != "foobar" {
+		t.Error("expected 'foobar' in top results")
+	}
+
+	// No match.
+	result = defaultFilter("zzz", items)
+	if len(result) != 0 {
+		t.Errorf("expected 0 matches for 'zzz', got %d", len(result))
+	}
+}
+
+func TestPopupList_CustomFilterFunc(t *testing.T) {
+	items := []PopupItem{
+		{Label: "alpha"},
+		{Label: "beta"},
+		{Label: "gamma"},
+	}
+	p := NewPopupList("Test", items, 80, 40)
+	p.FilterFunc = func(query string, allItems []PopupItem) []PopupItem {
+		// Custom: only return items whose label starts with query.
+		var result []PopupItem
+		for _, item := range allItems {
+			if strings.HasPrefix(item.Label, query) {
+				result = append(result, item)
+			}
+		}
+		return result
+	}
+
+	p.HandleKey("b", "b")
+	if len(p.filtered) != 1 || p.filtered[0].Label != "beta" {
+		t.Errorf("expected ['beta'], got %v", p.filtered)
+	}
+}
+
+func TestPopupList_Render(t *testing.T) {
+	items := []PopupItem{
+		{Label: "alpha", Description: "[test]"},
+		{Label: "beta", Description: "[test]", Active: true},
+	}
+	p := NewPopupList("My List", items, 80, 40)
+	p.Subtitle = "Some subtitle"
+
+	rendered := p.Render()
+	if rendered == "" {
+		t.Fatal("expected non-empty rendered output")
+	}
+
+	// Strip ANSI escape sequences for content checking.
+	plain := stripAnsi(rendered)
+	if !strings.Contains(plain, "My List") {
+		t.Error("expected title 'My List' in rendered output")
+	}
+	if !strings.Contains(plain, "alpha") {
+		t.Error("expected 'alpha' in rendered output")
+	}
+	if !strings.Contains(plain, "beta") {
+		t.Error("expected 'beta' in rendered output")
+	}
+	if !strings.Contains(plain, "✓") {
+		t.Error("expected checkmark for active item")
+	}
+}
+
+func TestPopupList_RenderCentered(t *testing.T) {
+	items := []PopupItem{
+		{Label: "item1"},
+	}
+	p := NewPopupList("Test", items, 80, 40)
+
+	centered := p.RenderCentered(80, 40)
+	if centered == "" {
+		t.Fatal("expected non-empty centered output")
+	}
+	// Should contain newlines for vertical centering.
+	lines := strings.Split(centered, "\n")
+	if len(lines) < 10 {
+		t.Errorf("expected centered output to have many lines, got %d", len(lines))
+	}
+}
+
+func TestPopupList_EmptyItems(t *testing.T) {
+	p := NewPopupList("Empty", nil, 80, 40)
+
+	rendered := p.Render()
+	if !strings.Contains(rendered, "No items") {
+		t.Error("expected 'No items' for empty list")
+	}
+
+	// Navigate on empty list shouldn't panic.
+	p.HandleKey("down", "")
+	p.HandleKey("up", "")
+	res := p.HandleKey("enter", "")
+	if res.Selected != nil {
+		t.Error("enter on empty list should not select")
+	}
+}
+
+func TestPopupList_SearchNoResults(t *testing.T) {
+	items := []PopupItem{
+		{Label: "alpha"},
+		{Label: "beta"},
+	}
+	p := NewPopupList("Test", items, 80, 40)
+
+	// Type something that doesn't match.
+	p.HandleKey("z", "z")
+	p.HandleKey("z", "z")
+	p.HandleKey("z", "z")
+
+	rendered := p.Render()
+	if !strings.Contains(rendered, "No matches") {
+		t.Error("expected 'No matches' message for empty search results")
+	}
+}
+
+func TestPopupList_CursorClamping(t *testing.T) {
+	items := []PopupItem{
+		{Label: "alpha"},
+		{Label: "beta"},
+		{Label: "gamma"},
+	}
+	p := NewPopupList("Test", items, 80, 40)
+
+	// Move to last item.
+	p.HandleKey("end", "")
+	if p.cursor != 2 {
+		t.Fatalf("expected cursor 2, got %d", p.cursor)
+	}
+
+	// Search that reduces list to 1 item → cursor should clamp.
+	p.HandleKey("a", "a")
+	p.HandleKey("l", "l")
+	// Only "alpha" should match.
+	if p.cursor >= len(p.filtered) {
+		t.Errorf("cursor %d should be < filtered count %d", p.cursor, len(p.filtered))
+	}
+}
+
+// stripAnsi is defined in usage_tracker_render_test.go

internal/ui/prefs/preferences.go

@@ -1,4 +1,4 @@
-package ui
+package prefs
 
 import (
 	"os"

internal/ui/progress/ollama.go

@@ -118,22 +118,33 @@ func (m ProgressModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 // status information and help text. Displays error messages if present or
 // a completion message when the download finishes.
 func (m ProgressModel) View() tea.View {
+	var v tea.View
+	v.AltScreen = true
+	v.MouseMode = tea.MouseModeCellMotion
+	v.ReportFocus = true
+	v.KeyboardEnhancements = tea.KeyboardEnhancements{
+		ReportEventTypes: true,
+	}
+
 	if m.err != nil {
-		return tea.NewView(fmt.Sprintf("Error: %s\n", m.err.Error()))
+		v.Content = fmt.Sprintf("Error: %s\n", m.err.Error())
+		return v
 	}
 
 	if m.complete {
-		return tea.NewView(fmt.Sprintf("\n%s%s\n\n%sComplete!\n",
+		v.Content = fmt.Sprintf("\n%s%s\n\n%sComplete!\n",
 			strings.Repeat(" ", padding),
 			m.progress.View(),
-			strings.Repeat(" ", padding)))
+			strings.Repeat(" ", padding))
+		return v
 	}
 
 	pad := strings.Repeat(" ", padding)
-	return tea.NewView(fmt.Sprintf("\n%s%s\n%s%s\n\n%s",
+	v.Content = fmt.Sprintf("\n%s%s\n%s%s\n\n%s",
 		pad, m.progress.View(),
 		pad, m.status,
-		pad+helpStyle("Press 'q' or Ctrl+C to cancel")))
+		pad+helpStyle("Press 'q' or Ctrl+C to cancel"))
+	return v
 }
 
 // ProgressReader wraps an io.Reader to intercept and parse Ollama pull operation

internal/ui/prompt.go

@@ -7,6 +7,8 @@ import (
 	"charm.land/bubbles/v2/textarea"
 	tea "charm.land/bubbletea/v2"
 	"charm.land/lipgloss/v2"
+
+	"github.com/mark3labs/kit/internal/ui/style"
 )
 
 // ---------------------------------------------------------------------------
@@ -204,7 +206,7 @@ func (p *promptOverlay) updateInput(msg tea.KeyPressMsg) (*promptResult, tea.Cmd
 // AppModel layout. The prompt replaces the normal input area (below the
 // separator and above the status bar) rather than taking over the full screen.
 func (p *promptOverlay) Render() string {
-	theme := GetTheme()
+	theme := style.GetTheme()
 	var content string
 
 	switch p.mode {
@@ -224,7 +226,7 @@ func (p *promptOverlay) Render() string {
 	)
 }
 
-func (p *promptOverlay) viewSelect(theme Theme) string {
+func (p *promptOverlay) viewSelect(theme style.Theme) string {
 	var lines []string
 	lines = append(lines, lipgloss.NewStyle().Bold(true).Foreground(theme.Text).Render(p.message))
 	lines = append(lines, "")
@@ -247,7 +249,7 @@ func (p *promptOverlay) viewSelect(theme Theme) string {
 	return strings.Join(lines, "\n")
 }
 
-func (p *promptOverlay) viewConfirm(theme Theme) string {
+func (p *promptOverlay) viewConfirm(theme style.Theme) string {
 	var lines []string
 	lines = append(lines, lipgloss.NewStyle().Bold(true).Foreground(theme.Text).Render(p.message))
 	lines = append(lines, "")
@@ -272,7 +274,7 @@ func (p *promptOverlay) viewConfirm(theme Theme) string {
 	return strings.Join(lines, "\n")
 }
 
-func (p *promptOverlay) viewInput(theme Theme) string {
+func (p *promptOverlay) viewInput(theme style.Theme) string {
 	var lines []string
 	lines = append(lines, lipgloss.NewStyle().Bold(true).Foreground(theme.Text).Render(p.message))
 	lines = append(lines, "")

internal/ui/render/blocks.go

@@ -0,0 +1,127 @@
+// Package render provides pure rendering functions for message blocks.
+// These functions are stateless and can be used by both streaming and
+// historical message rendering paths, eliminating code duplication.
+package render
+
+import (
+	"fmt"
+	"strings"
+
+	"charm.land/lipgloss/v2"
+	"github.com/indaco/herald"
+
+	"github.com/mark3labs/kit/internal/ui/style"
+)
+
+// UserBlock renders a user message with herald Tip styling.
+func UserBlock(content string, ty *herald.Typography, theme style.Theme) string {
+	if strings.TrimSpace(content) == "" {
+		content = "(empty message)"
+	}
+
+	rendered := ty.Tip(content)
+	return styleMarginBottom(theme, rendered)
+}
+
+// AssistantBlock renders an assistant message with markdown styling.
+func AssistantBlock(content string, width int, theme style.Theme) string {
+	if strings.TrimSpace(content) == "" {
+		return ""
+	}
+
+	rendered := style.ToMarkdown(content, width-4)
+	return styleMarginBottom(theme, rendered)
+}
+
+// ReasoningBlock renders a reasoning/thinking block with muted italic text.
+// If duration > 0, shows "Thought for Xs" label. Otherwise shows just "Thought".
+func ReasoningBlock(content string, duration int64, ty *herald.Typography, theme style.Theme) string {
+	if strings.TrimSpace(content) == "" {
+		return ""
+	}
+
+	// Match live streaming styling: muted italic text
+	lines := strings.Split(strings.TrimRight(content, "\n"), "\n")
+	contentStr := strings.TrimLeft(strings.Join(lines, "\n"), " \t\n")
+	mutedStyle := lipgloss.NewStyle().Foreground(theme.Muted)
+	contentRendered := mutedStyle.Render(ty.Italic(contentStr))
+
+	// Build label based on duration
+	if duration > 0 {
+		var durationStr string
+		if duration < 1000 {
+			durationStr = fmt.Sprintf("%dms", duration)
+		} else {
+			durationStr = fmt.Sprintf("%.1fs", float64(duration)/1000)
+		}
+		labelPart := lipgloss.NewStyle().Foreground(theme.VeryMuted).Render("Thought for ")
+		durationPart := lipgloss.NewStyle().Foreground(theme.Accent).Render(durationStr)
+		label := labelPart + durationPart
+		rendered := contentRendered + "\n" + label
+		return styleMarginBottom(theme, rendered)
+	}
+
+	label := lipgloss.NewStyle().Foreground(theme.VeryMuted).Render("Thought")
+	rendered := contentRendered + "\n" + label
+
+	return styleMarginBottom(theme, rendered)
+}
+
+// SystemBlock renders a system message with herald Note styling.
+func SystemBlock(content string, ty *herald.Typography, theme style.Theme) string {
+	if strings.TrimSpace(content) == "" {
+		content = "No content available"
+	}
+
+	rendered := ty.Note(content)
+	return styleMarginBottom(theme, rendered)
+}
+
+// ErrorBlock renders an error message with herald Caution styling.
+func ErrorBlock(errorMsg string, ty *herald.Typography, theme style.Theme) string {
+	rendered := ty.Caution(errorMsg)
+	return styleMarginBottom(theme, rendered)
+}
+
+// ToolBlock renders a tool execution result with header and body.
+func ToolBlock(displayName, params, body string, isError bool, width int, ty *herald.Typography, theme style.Theme) string {
+	var icon string
+	iconColor := theme.Success
+	if isError {
+		icon = "×"
+		iconColor = theme.Error
+	} else {
+		icon = "✓"
+	}
+
+	// Style the tool name with color
+	nameColor := theme.Info
+	if isError {
+		nameColor = theme.Error
+	}
+	styledName := lipgloss.NewStyle().Foreground(nameColor).Bold(true).Render(displayName)
+	styledIcon := lipgloss.NewStyle().Foreground(iconColor).Render(icon)
+
+	// Build the content: icon + name + params on first line, then body
+	headerLine := styledIcon + " " + styledName
+	if params != "" {
+		headerLine += " " + lipgloss.NewStyle().Foreground(theme.Muted).Render(params)
+	}
+
+	if strings.TrimSpace(body) == "" {
+		body = ty.Italic("(no output)")
+	}
+
+	// Compose: icon + name + params, then body
+	fullContent := ty.Compose(
+		headerLine,
+		"",
+		body,
+	)
+	return styleMarginBottom(theme, fullContent)
+}
+
+// styleMarginBottom applies a 1-line margin bottom using the theme.
+func styleMarginBottom(theme style.Theme, content string) string {
+	return lipgloss.NewStyle().MarginBottom(1).Render(content)
+}

internal/ui/scrolllist.go

@@ -0,0 +1,693 @@
+package ui
+
+import (
+	"strings"
+	"time"
+
+	xansi "github.com/charmbracelet/x/ansi"
+
+	"github.com/mark3labs/kit/internal/ui/selection"
+)
+
+// MessageItem is the interface all scrollback messages must implement.
+// This allows lazy rendering - messages are only rendered when visible.
+type MessageItem interface {
+	// Render returns the styled content for this message at the given width.
+	// Implementations should cache the result to avoid re-rendering.
+	Render(width int) string
+
+	// Height returns the number of lines this message occupies when rendered.
+	Height() int
+
+	// ID returns a unique identifier for this message (for tracking).
+	ID() string
+}
+
+// ScrollList manages a viewport over a list of MessageItems.
+// It handles offset-based scrolling, lazy rendering, and character-level
+// text selection (crush-style). Only visible items are rendered on each View() call.
+type ScrollList struct {
+	items      []MessageItem
+	offsetIdx  int // Index of first visible item
+	offsetLine int // Lines to skip from first visible item
+	width      int
+	height     int  // Viewport height in lines
+	autoScroll bool // Whether to auto-scroll to bottom on new content
+	itemGap    int  // Number of blank lines between items (0 = no gap)
+
+	// Character-level text selection (crush-style).
+	sel selection.State
+}
+
+// NewScrollList creates a new ScrollList with the given dimensions.
+func NewScrollList(width, height int) *ScrollList {
+	return &ScrollList{
+		items:      []MessageItem{},
+		offsetIdx:  0,
+		offsetLine: 0,
+		width:      width,
+		height:     height,
+		autoScroll: true,
+		sel:        selection.NewState(),
+	}
+}
+
+// SetItems replaces the items in the scroll list. If auto-scroll is enabled,
+// the viewport will scroll to the bottom to show the latest content.
+func (s *ScrollList) SetItems(items []MessageItem) {
+	s.items = items
+	if s.autoScroll {
+		s.GotoBottom()
+	}
+}
+
+// SetHeight updates the viewport height. Called when the terminal is resized.
+func (s *ScrollList) SetHeight(height int) {
+	s.height = height
+	s.clampOffset()
+}
+
+// SetWidth updates the viewport width. Called when the terminal is resized.
+// This may invalidate cached renders in MessageItems.
+func (s *ScrollList) SetWidth(width int) {
+	s.width = width
+	s.clampOffset()
+}
+
+// SetItemGap sets the number of blank lines between items (0 = no gap).
+func (s *ScrollList) SetItemGap(gap int) {
+	s.itemGap = gap
+}
+
+// ItemGap returns the current gap between items.
+func (s *ScrollList) ItemGap() int {
+	return s.itemGap
+}
+
+// --------------------------------------------------------------------------
+// Mouse event handling — character-level text selection (crush-style)
+// --------------------------------------------------------------------------
+
+// HandleMouseDown handles mouse button press. Detects single, double, and
+// triple clicks for character, word, and line selection respectively.
+// Returns true if the click was handled.
+func (s *ScrollList) HandleMouseDown(x, y int) bool {
+	if len(s.items) == 0 {
+		return false
+	}
+
+	itemIdx, lineIdx := s.getItemAndLineAtY(y)
+	if itemIdx < 0 {
+		return false
+	}
+
+	// Multi-click detection (crush-style).
+	now := time.Now()
+	if now.Sub(s.sel.LastClickTime) <= selection.DoubleClickThreshold &&
+		abs(x-s.sel.LastClickX) <= selection.ClickTolerance &&
+		abs(y-s.sel.LastClickY) <= selection.ClickTolerance {
+		s.sel.ClickCount++
+	} else {
+		s.sel.ClickCount = 1
+	}
+	s.sel.LastClickTime = now
+	s.sel.LastClickX = x
+	s.sel.LastClickY = y
+
+	switch s.sel.ClickCount {
+	case 1:
+		// Single click: start character-level drag selection.
+		s.sel.MouseDown = true
+		s.sel.MouseDownItemIdx = itemIdx
+		s.sel.MouseDownLineIdx = lineIdx
+		s.sel.MouseDownCol = x
+		s.sel.DragItemIdx = itemIdx
+		s.sel.DragLineIdx = lineIdx
+		s.sel.DragCol = x
+
+	case 2:
+		// Double click: select word at position.
+		s.selectWord(itemIdx, lineIdx, x)
+
+	case 3:
+		// Triple click: select entire line.
+		s.selectLine(itemIdx, lineIdx)
+		s.sel.ClickCount = 0 // Reset after triple
+	}
+
+	return true
+}
+
+// HandleMouseDrag handles mouse motion while button is held.
+// Updates the selection endpoint for character-level precision.
+// Returns true if selection was updated.
+func (s *ScrollList) HandleMouseDrag(x, y int) bool {
+	if !s.sel.MouseDown {
+		return false
+	}
+
+	if len(s.items) == 0 {
+		return false
+	}
+
+	itemIdx, lineIdx := s.getItemAndLineAtY(y)
+	if itemIdx < 0 {
+		return false
+	}
+
+	s.sel.DragItemIdx = itemIdx
+	s.sel.DragLineIdx = lineIdx
+	s.sel.DragCol = x
+
+	return true
+}
+
+// HandleMouseUp handles mouse button release.
+// Returns true if there was an active selection.
+func (s *ScrollList) HandleMouseUp() bool {
+	if !s.sel.MouseDown {
+		return false
+	}
+	s.sel.MouseDown = false
+	return s.sel.HasSelection()
+}
+
+// HasSelection returns true if there is a non-empty active selection.
+func (s *ScrollList) HasSelection() bool {
+	return s.sel.HasSelection()
+}
+
+// ClearSelection clears the current text selection.
+func (s *ScrollList) ClearSelection() {
+	s.sel.Clear()
+}
+
+// ExtractSelectedText returns the plain text content of the current selection
+// by walking through selected items and extracting text at the character level
+// using the ultraviolet cell buffer (ANSI-aware).
+func (s *ScrollList) ExtractSelectedText() string {
+	r := s.sel.GetRange()
+	if r.IsEmpty() {
+		return ""
+	}
+
+	var sb strings.Builder
+
+	for itemIdx := r.StartItemIdx; itemIdx <= r.EndItemIdx && itemIdx < len(s.items); itemIdx++ {
+		item := s.items[itemIdx]
+		content := item.Render(s.width)
+		contentLines := strings.Split(content, "\n")
+
+		for lineIdx, line := range contentLines {
+			inRange, startCol, endCol := selection.IsLineInRange(r, itemIdx, lineIdx)
+			if !inRange {
+				continue
+			}
+
+			text := selection.ExtractText(line, startCol, endCol)
+			if text != "" {
+				if sb.Len() > 0 {
+					sb.WriteString("\n")
+				}
+				sb.WriteString(text)
+			}
+		}
+	}
+
+	return sb.String()
+}
+
+// selectWord selects the word at the given position using UAX#29 word
+// segmentation and display-width-aware column calculations.
+func (s *ScrollList) selectWord(itemIdx, lineIdx, x int) {
+	if itemIdx < 0 || itemIdx >= len(s.items) {
+		return
+	}
+
+	item := s.items[itemIdx]
+	content := item.Render(s.width)
+	lines := strings.Split(content, "\n")
+	if lineIdx < 0 || lineIdx >= len(lines) {
+		return
+	}
+
+	// Strip ANSI codes for word boundary detection.
+	plainLine := xansi.Strip(lines[lineIdx])
+	startCol, endCol := selection.FindWordBoundaries(plainLine, x)
+
+	if startCol == endCol {
+		// No word at this position — set up single-click drag state.
+		s.sel.MouseDown = true
+		s.sel.MouseDownItemIdx = itemIdx
+		s.sel.MouseDownLineIdx = lineIdx
+		s.sel.MouseDownCol = x
+		s.sel.DragItemIdx = itemIdx
+		s.sel.DragLineIdx = lineIdx
+		s.sel.DragCol = x
+		return
+	}
+
+	// Set selection to the word boundaries.
+	s.sel.MouseDown = true
+	s.sel.MouseDownItemIdx = itemIdx
+	s.sel.MouseDownLineIdx = lineIdx
+	s.sel.MouseDownCol = startCol
+	s.sel.DragItemIdx = itemIdx
+	s.sel.DragLineIdx = lineIdx
+	s.sel.DragCol = endCol
+}
+
+// selectLine selects the entire line at the given position.
+func (s *ScrollList) selectLine(itemIdx, lineIdx int) {
+	if itemIdx < 0 || itemIdx >= len(s.items) {
+		return
+	}
+
+	item := s.items[itemIdx]
+	content := item.Render(s.width)
+	lines := strings.Split(content, "\n")
+	if lineIdx < 0 || lineIdx >= len(lines) {
+		return
+	}
+
+	lineWidth := xansi.StringWidth(lines[lineIdx])
+
+	s.sel.MouseDown = true
+	s.sel.MouseDownItemIdx = itemIdx
+	s.sel.MouseDownLineIdx = lineIdx
+	s.sel.MouseDownCol = 0
+	s.sel.DragItemIdx = itemIdx
+	s.sel.DragLineIdx = lineIdx
+	s.sel.DragCol = lineWidth
+}
+
+// getItemAndLineAtY converts a viewport-relative Y coordinate to item index
+// and line index within that item. Accounts for scroll offset and item gaps.
+// Returns (-1, -1) if Y is outside the viewport or beyond all items.
+//
+// IMPORTANT: Uses Render()+line counting (not Height()) to compute item height,
+// because Height() on some MessageItem implementations (e.g. StreamingMessageItem
+// for reasoning blocks) may return 0 when the render cache is empty.
+func (s *ScrollList) getItemAndLineAtY(y int) (itemIdx, lineIdx int) {
+	if y < 0 || y >= s.height || len(s.items) == 0 {
+		return -1, -1
+	}
+
+	currentY := 0
+	for idx := s.offsetIdx; idx < len(s.items); idx++ {
+		item := s.items[idx]
+		// Compute height the same way View() does: render, then count lines.
+		itemHeight := s.renderedHeight(item)
+
+		// Account for partial visibility of the first item.
+		startLine := 0
+		if idx == s.offsetIdx {
+			startLine = s.offsetLine
+			itemHeight -= s.offsetLine
+		}
+
+		if y >= currentY && y < currentY+itemHeight {
+			return idx, (y - currentY) + startLine
+		}
+
+		currentY += itemHeight
+
+		// Add gap after item (except last).
+		if s.itemGap > 0 && idx < len(s.items)-1 {
+			currentY += s.itemGap
+		}
+
+		if currentY >= s.height {
+			break
+		}
+	}
+
+	return -1, -1
+}
+
+// --------------------------------------------------------------------------
+// Scrolling
+// --------------------------------------------------------------------------
+
+// ScrollBy scrolls the viewport by the given number of lines.
+// Positive = scroll down, negative = scroll up.
+func (s *ScrollList) ScrollBy(lines int) {
+	if lines > 0 {
+		// Scroll down
+		for lines > 0 && s.offsetIdx < len(s.items) {
+			if s.offsetIdx >= len(s.items) {
+				break
+			}
+			currentItem := s.items[s.offsetIdx]
+			itemHeight := currentItem.Height()
+			remainingLines := itemHeight - s.offsetLine
+
+			if lines >= remainingLines {
+				// Move to next item
+				s.offsetIdx++
+				s.offsetLine = 0
+				lines -= remainingLines
+				// Consume gap lines between items
+				if s.itemGap > 0 && s.offsetIdx < len(s.items) {
+					if lines >= s.itemGap {
+						lines -= s.itemGap
+					} else {
+						lines = 0
+					}
+				}
+			} else {
+				// Stay on current item, skip more lines
+				s.offsetLine += lines
+				lines = 0
+			}
+		}
+	} else if lines < 0 {
+		// Scroll up
+		lines = -lines
+		for lines > 0 && (s.offsetIdx > 0 || s.offsetLine > 0) {
+			if s.offsetLine > 0 {
+				// Scroll within current item
+				if lines >= s.offsetLine {
+					lines -= s.offsetLine
+					s.offsetLine = 0
+				} else {
+					s.offsetLine -= lines
+					lines = 0
+				}
+			} else if s.offsetIdx > 0 {
+				// Consume gap lines between items
+				if s.itemGap > 0 {
+					if lines > s.itemGap {
+						lines -= s.itemGap
+					} else {
+						lines = 0
+						continue
+					}
+				}
+				// Move to previous item
+				s.offsetIdx--
+				if s.offsetIdx < len(s.items) {
+					currentItem := s.items[s.offsetIdx]
+					itemHeight := currentItem.Height()
+
+					if lines >= itemHeight {
+						lines -= itemHeight
+						s.offsetLine = 0
+					} else {
+						s.offsetLine = itemHeight - lines
+						lines = 0
+					}
+				}
+			}
+		}
+	}
+	s.clampOffset()
+}
+
+// GotoBottom scrolls to the end of the list.
+func (s *ScrollList) GotoBottom() {
+	if len(s.items) == 0 {
+		s.offsetIdx = 0
+		s.offsetLine = 0
+		return
+	}
+
+	// Calculate total height including gaps
+	totalHeight := 0
+	for i, item := range s.items {
+		rendered := item.Render(s.width)
+		itemHeight := strings.Count(rendered, "\n") + 1
+		totalHeight += itemHeight
+		if s.itemGap > 0 && i < len(s.items)-1 {
+			totalHeight += s.itemGap
+		}
+	}
+
+	// If content fits in viewport, start at top
+	if totalHeight <= s.height {
+		s.offsetIdx = 0
+		s.offsetLine = 0
+		return
+	}
+
+	// Otherwise, position viewport at bottom
+	remaining := totalHeight - s.height
+	for idx := 0; idx < len(s.items); idx++ {
+		rendered := s.items[idx].Render(s.width)
+		itemHeight := strings.Count(rendered, "\n") + 1
+		if remaining < itemHeight {
+			s.offsetIdx = idx
+			s.offsetLine = remaining
+			return
+		}
+		remaining -= itemHeight
+		if s.itemGap > 0 && idx < len(s.items)-1 {
+			remaining -= s.itemGap
+		}
+	}
+
+	// Fallback: show last item
+	s.offsetIdx = max(0, len(s.items)-1)
+	s.offsetLine = 0
+}
+
+// GotoTop scrolls to the beginning of the list.
+func (s *ScrollList) GotoTop() {
+	s.offsetIdx = 0
+	s.offsetLine = 0
+}
+
+// AtBottom returns true if the viewport is at the bottom of the list.
+func (s *ScrollList) AtBottom() bool {
+	if len(s.items) == 0 {
+		return true
+	}
+
+	visibleHeight := 0
+	for idx := s.offsetIdx; idx < len(s.items); idx++ {
+		item := s.items[idx]
+		rendered := item.Render(s.width)
+		itemHeight := strings.Count(rendered, "\n") + 1
+
+		if idx == s.offsetIdx {
+			visibleHeight += itemHeight - s.offsetLine
+		} else {
+			visibleHeight += itemHeight
+		}
+
+		if s.itemGap > 0 && idx < len(s.items)-1 {
+			visibleHeight += s.itemGap
+		}
+
+		if visibleHeight >= s.height {
+			return false
+		}
+	}
+
+	return true
+}
+
+// AtTop returns true if the viewport is at the top of the list.
+func (s *ScrollList) AtTop() bool {
+	return s.offsetIdx == 0 && s.offsetLine == 0
+}
+
+// --------------------------------------------------------------------------
+// Rendering
+// --------------------------------------------------------------------------
+
+// View renders the visible portion of the scrollback.
+// Only items that fit within the viewport height are rendered.
+// ALWAYS returns exactly s.height lines (padded with empty lines if needed)
+// to ensure the input/footer stay fixed at the bottom.
+//
+// When an active selection exists, character-level highlighting is applied
+// using ultraviolet ScreenBuffer for ANSI-aware cell manipulation.
+func (s *ScrollList) View() string {
+	if s.height <= 0 {
+		return ""
+	}
+
+	selRange := s.sel.GetRange()
+	hasSelection := !selRange.IsEmpty()
+
+	var lines []string
+	remainingHeight := s.height
+
+	if len(s.items) > 0 {
+		for idx := s.offsetIdx; idx < len(s.items) && remainingHeight > 0; idx++ {
+			item := s.items[idx]
+			content := item.Render(s.width)
+			contentLines := strings.Split(content, "\n")
+
+			startLine := 0
+			if idx == s.offsetIdx {
+				startLine = s.offsetLine
+			}
+
+			for i := startLine; i < len(contentLines) && remainingHeight > 0; i++ {
+				line := contentLines[i]
+
+				// Apply character-level selection highlighting.
+				if hasSelection {
+					inRange, startCol, endCol := selection.IsLineInRange(selRange, idx, i)
+					if inRange {
+						line = selection.HighlightLine(line, startCol, endCol)
+					}
+				}
+
+				lines = append(lines, line)
+				remainingHeight--
+			}
+
+			// Add gap lines between items.
+			if remainingHeight > 0 && idx < len(s.items)-1 && s.itemGap > 0 {
+				for g := 0; g < s.itemGap && remainingHeight > 0; g++ {
+					lines = append(lines, "")
+					remainingHeight--
+				}
+			}
+		}
+	}
+
+	// Pad with empty lines to ensure exactly s.height lines.
+	for remainingHeight > 0 {
+		lines = append(lines, "")
+		remainingHeight--
+	}
+
+	return strings.Join(lines, "\n")
+}
+
+// ScrollPercent returns the current scroll position as a percentage (0.0-1.0).
+// 0.0 = at top, 1.0 = at bottom. Useful for scroll indicators.
+func (s *ScrollList) ScrollPercent() float64 {
+	if len(s.items) == 0 {
+		return 0.0
+	}
+
+	totalHeight := 0
+	for _, item := range s.items {
+		totalHeight += item.Height()
+	}
+
+	if totalHeight <= s.height {
+		return 1.0
+	}
+
+	linesAbove := 0
+	for i := 0; i < s.offsetIdx && i < len(s.items); i++ {
+		linesAbove += s.items[i].Height()
+	}
+	linesAbove += s.offsetLine
+
+	scrollableHeight := totalHeight - s.height
+	if scrollableHeight <= 0 {
+		return 1.0
+	}
+
+	percent := float64(linesAbove) / float64(scrollableHeight)
+	if percent > 1.0 {
+		percent = 1.0
+	}
+	if percent < 0.0 {
+		percent = 0.0
+	}
+	return percent
+}
+
+// clampOffset ensures the offset values are within valid bounds after
+// resizing or scrolling operations.
+func (s *ScrollList) clampOffset() {
+	if len(s.items) == 0 {
+		s.offsetIdx = 0
+		s.offsetLine = 0
+		return
+	}
+
+	if s.offsetIdx >= len(s.items) {
+		s.offsetIdx = len(s.items) - 1
+	}
+	if s.offsetIdx < 0 {
+		s.offsetIdx = 0
+	}
+
+	if s.offsetIdx < len(s.items) {
+		rendered := s.items[s.offsetIdx].Render(s.width)
+		itemHeight := strings.Count(rendered, "\n") + 1
+		if s.offsetLine >= itemHeight {
+			s.offsetLine = max(0, itemHeight-1)
+		}
+	}
+	if s.offsetLine < 0 {
+		s.offsetLine = 0
+	}
+
+	// Prevent scrolling past the bottom
+	totalHeight := 0
+	for i, item := range s.items {
+		rendered := item.Render(s.width)
+		totalHeight += strings.Count(rendered, "\n") + 1
+		if s.itemGap > 0 && i < len(s.items)-1 {
+			totalHeight += s.itemGap
+		}
+	}
+
+	if totalHeight <= s.height {
+		s.offsetIdx = 0
+		s.offsetLine = 0
+		return
+	}
+
+	linesAbove := 0
+	for i := 0; i < s.offsetIdx; i++ {
+		rendered := s.items[i].Render(s.width)
+		linesAbove += strings.Count(rendered, "\n") + 1
+		if s.itemGap > 0 && i < len(s.items)-1 {
+			linesAbove += s.itemGap
+		}
+	}
+	linesAbove += s.offsetLine
+
+	linesFromCurrentToEnd := totalHeight - linesAbove
+	if linesFromCurrentToEnd < s.height {
+		targetLine := totalHeight - s.height
+		currentLine := 0
+
+		for idx := 0; idx < len(s.items); idx++ {
+			rendered := s.items[idx].Render(s.width)
+			itemHeight := strings.Count(rendered, "\n") + 1
+
+			if currentLine+itemHeight > targetLine {
+				s.offsetIdx = idx
+				s.offsetLine = targetLine - currentLine
+				return
+			}
+
+			currentLine += itemHeight
+			if s.itemGap > 0 && idx < len(s.items)-1 {
+				currentLine += s.itemGap
+			}
+		}
+	}
+}
+
+// renderedHeight returns the height of a message item in lines by actually
+// rendering it. This is the single source of truth for item height — it
+// matches exactly what View() produces, unlike item.Height() which may
+// return stale/zero values for uncached items (e.g. reasoning blocks).
+func (s *ScrollList) renderedHeight(item MessageItem) int {
+	rendered := item.Render(s.width)
+	if rendered == "" {
+		return 0
+	}
+	return strings.Count(rendered, "\n") + 1
+}
+
+// abs returns the absolute value of x.
+func abs(x int) int {
+	if x < 0 {
+		return -x
+	}
+	return x
+}

internal/ui/selection/selection.go

@@ -0,0 +1,324 @@
+// Package selection provides character-level text selection for terminal UIs.
+//
+// It handles converting mouse coordinates (in terminal cells) to character
+// positions within rendered ANSI-styled text, supporting multi-byte characters,
+// wide characters (CJK, emoji), and word/line selection via double/triple click.
+//
+// The approach is modeled after Charm's crush: all coordinate calculations use
+// display columns (terminal cells), not byte offsets or rune counts. The
+// ultraviolet ScreenBuffer provides the bridge between rendered ANSI strings
+// and individual character cells.
+package selection
+
+import (
+	"image"
+	"strings"
+	"time"
+
+	uv "github.com/charmbracelet/ultraviolet"
+	xansi "github.com/charmbracelet/x/ansi"
+	"github.com/clipperhouse/displaywidth"
+	"github.com/clipperhouse/uax29/v2/words"
+)
+
+// DoubleClickThreshold is the maximum time between clicks for multi-click.
+const DoubleClickThreshold = 400 * time.Millisecond
+
+// ClickTolerance is the pixel/cell tolerance for multi-click detection.
+const ClickTolerance = 2
+
+// State tracks the full state of a mouse text selection.
+type State struct {
+	// Whether a mouse button is currently held down.
+	MouseDown bool
+
+	// Position where mouse was first pressed (viewport-relative).
+	MouseDownItemIdx int
+	MouseDownLineIdx int
+	MouseDownCol     int
+
+	// Current drag position (viewport-relative).
+	DragItemIdx int
+	DragLineIdx int
+	DragCol     int
+
+	// Multi-click detection.
+	LastClickTime time.Time
+	LastClickX    int
+	LastClickY    int
+	ClickCount    int
+}
+
+// Range represents a normalized (start <= end) selection range.
+type Range struct {
+	StartItemIdx int
+	StartLine    int
+	StartCol     int
+	EndItemIdx   int
+	EndLine      int
+	EndCol       int
+}
+
+// IsEmpty returns true if the range selects nothing.
+func (r Range) IsEmpty() bool {
+	return r.StartItemIdx < 0 || r.EndItemIdx < 0 ||
+		(r.StartItemIdx == r.EndItemIdx && r.StartLine == r.EndLine && r.StartCol == r.EndCol)
+}
+
+// NewState creates a new empty selection state.
+func NewState() State {
+	return State{
+		MouseDownItemIdx: -1,
+		DragItemIdx:      -1,
+	}
+}
+
+// Clear resets all selection state.
+func (s *State) Clear() {
+	s.MouseDown = false
+	s.MouseDownItemIdx = -1
+	s.MouseDownLineIdx = 0
+	s.MouseDownCol = 0
+	s.DragItemIdx = -1
+	s.DragLineIdx = 0
+	s.DragCol = 0
+	s.LastClickTime = time.Time{}
+	s.LastClickX = 0
+	s.LastClickY = 0
+	s.ClickCount = 0
+}
+
+// HasSelection returns true if there is a non-empty active selection.
+func (s *State) HasSelection() bool {
+	return s.MouseDownItemIdx >= 0 && s.DragItemIdx >= 0 && !s.GetRange().IsEmpty()
+}
+
+// GetRange returns the normalized selection range (start <= end).
+func (s *State) GetRange() Range {
+	if s.MouseDownItemIdx < 0 || s.DragItemIdx < 0 {
+		return Range{StartItemIdx: -1, EndItemIdx: -1}
+	}
+
+	downItem := s.MouseDownItemIdx
+	downLine := s.MouseDownLineIdx
+	downCol := s.MouseDownCol
+	dragItem := s.DragItemIdx
+	dragLine := s.DragLineIdx
+	dragCol := s.DragCol
+
+	// Determine if dragging forward or backward.
+	forward := dragItem > downItem ||
+		(dragItem == downItem && dragLine > downLine) ||
+		(dragItem == downItem && dragLine == downLine && dragCol >= downCol)
+
+	if forward {
+		return Range{
+			StartItemIdx: downItem,
+			StartLine:    downLine,
+			StartCol:     downCol,
+			EndItemIdx:   dragItem,
+			EndLine:      dragLine,
+			EndCol:       dragCol,
+		}
+	}
+	return Range{
+		StartItemIdx: dragItem,
+		StartLine:    dragLine,
+		StartCol:     dragCol,
+		EndItemIdx:   downItem,
+		EndLine:      downLine,
+		EndCol:       downCol,
+	}
+}
+
+// IsLineInRange checks if a specific line within an item falls inside the
+// selection range. Returns (inRange, startCol, endCol) where startCol == -1
+// means the entire line is selected. startCol == endCol means no selection
+// on this line.
+func IsLineInRange(r Range, itemIdx, lineIdx int) (bool, int, int) {
+	if r.IsEmpty() {
+		return false, 0, 0
+	}
+
+	// Outside item range entirely.
+	if itemIdx < r.StartItemIdx || itemIdx > r.EndItemIdx {
+		return false, 0, 0
+	}
+
+	// Single-item selection.
+	if r.StartItemIdx == r.EndItemIdx {
+		if itemIdx != r.StartItemIdx {
+			return false, 0, 0
+		}
+		if lineIdx < r.StartLine || lineIdx > r.EndLine {
+			return false, 0, 0
+		}
+		if r.StartLine == r.EndLine {
+			// Single line: specific column range.
+			return true, r.StartCol, r.EndCol
+		}
+		if lineIdx == r.StartLine {
+			return true, r.StartCol, -1 // from startCol to end of line
+		}
+		if lineIdx == r.EndLine {
+			return true, 0, r.EndCol // from start of line to endCol
+		}
+		return true, -1, -1 // full line (middle of multi-line selection)
+	}
+
+	// Multi-item selection.
+	if itemIdx == r.StartItemIdx {
+		if lineIdx < r.StartLine {
+			return false, 0, 0
+		}
+		if lineIdx == r.StartLine {
+			return true, r.StartCol, -1
+		}
+		return true, -1, -1 // full line
+	}
+	if itemIdx == r.EndItemIdx {
+		if lineIdx > r.EndLine {
+			return false, 0, 0
+		}
+		if lineIdx == r.EndLine {
+			return true, 0, r.EndCol
+		}
+		return true, -1, -1 // full line
+	}
+
+	// Middle item: fully selected.
+	return true, -1, -1
+}
+
+// FindWordBoundaries finds the start and end column of the word at the given
+// column position in a plain-text line (ANSI codes already stripped).
+// Returns (startCol, endCol) where endCol is exclusive.
+// Uses UAX#29 word segmentation and display-width-aware column tracking.
+func FindWordBoundaries(line string, col int) (startCol, endCol int) {
+	if line == "" || col < 0 {
+		return 0, 0
+	}
+
+	// Segment the line into words using UAX#29.
+	lineCol := 0
+	iter := words.FromString(line)
+	for iter.Next() {
+		token := iter.Value()
+		tokenWidth := displaywidth.String(token)
+
+		graphemeStart := lineCol
+		graphemeEnd := lineCol + tokenWidth
+		lineCol += tokenWidth
+
+		// If clicked before this token, no word here.
+		if col < graphemeStart {
+			return col, col
+		}
+
+		// If clicked within this token, return its boundaries.
+		if col >= graphemeStart && col < graphemeEnd {
+			// Whitespace tokens produce empty selection.
+			if strings.TrimSpace(token) == "" {
+				return col, col
+			}
+			return graphemeStart, graphemeEnd
+		}
+	}
+
+	return col, col
+}
+
+// HighlightLine applies reverse-video highlighting to a portion of a rendered
+// line (which may contain ANSI escape codes). startCol/endCol are in display
+// columns. If startCol == -1, the entire line is highlighted. If startCol ==
+// endCol, returns the line unchanged.
+//
+// Uses ultraviolet ScreenBuffer for cell-level ANSI manipulation.
+func HighlightLine(line string, startCol, endCol int) string {
+	if line == "" {
+		return line
+	}
+
+	lineWidth := xansi.StringWidth(line)
+	if lineWidth == 0 {
+		return line
+	}
+
+	// Full-line highlight.
+	if startCol == -1 {
+		startCol = 0
+		endCol = lineWidth
+	}
+
+	if startCol >= endCol || startCol >= lineWidth {
+		return line
+	}
+	if endCol > lineWidth {
+		endCol = lineWidth
+	}
+
+	// Parse the styled line into a cell buffer.
+	area := image.Rect(0, 0, lineWidth, 1)
+	buf := uv.NewScreenBuffer(lineWidth, 1)
+	styled := uv.NewStyledString(line)
+	styled.Draw(&buf, area)
+
+	// Apply reverse attribute to cells in the selection range.
+	if buf.Height() > 0 {
+		bufLine := buf.Line(0)
+		for x := startCol; x < endCol && x < len(bufLine); x++ {
+			cell := bufLine.At(x)
+			if cell != nil {
+				cell.Style.Attrs |= uv.AttrReverse
+			}
+		}
+	}
+
+	return buf.Render()
+}
+
+// ExtractText extracts plain text from a rendered ANSI string within the given
+// column range on a single line. Uses ultraviolet to parse ANSI and extract
+// character content.
+func ExtractText(line string, startCol, endCol int) string {
+	if line == "" {
+		return ""
+	}
+
+	lineWidth := xansi.StringWidth(line)
+	if lineWidth == 0 {
+		return ""
+	}
+
+	// Full-line extraction.
+	if startCol == -1 {
+		startCol = 0
+		endCol = lineWidth
+	}
+
+	if startCol >= endCol || startCol >= lineWidth {
+		return ""
+	}
+	if endCol > lineWidth {
+		endCol = lineWidth
+	}
+
+	// Parse to cell buffer.
+	area := image.Rect(0, 0, lineWidth, 1)
+	buf := uv.NewScreenBuffer(lineWidth, 1)
+	styled := uv.NewStyledString(line)
+	styled.Draw(&buf, area)
+
+	var sb strings.Builder
+	if buf.Height() > 0 {
+		bufLine := buf.Line(0)
+		for x := startCol; x < endCol && x < len(bufLine); x++ {
+			cell := bufLine.At(x)
+			if cell != nil && cell.Content != "" {
+				sb.WriteString(cell.Content)
+			}
+		}
+	}
+
+	return sb.String()
+}

internal/ui/selection/selection_test.go

@@ -0,0 +1,400 @@
+package selection
+
+import (
+	"testing"
+	"time"
+)
+
+func TestNewState(t *testing.T) {
+	s := NewState()
+	if s.MouseDownItemIdx != -1 {
+		t.Errorf("expected MouseDownItemIdx -1, got %d", s.MouseDownItemIdx)
+	}
+	if s.DragItemIdx != -1 {
+		t.Errorf("expected DragItemIdx -1, got %d", s.DragItemIdx)
+	}
+	if s.MouseDown {
+		t.Error("expected MouseDown false")
+	}
+	if s.HasSelection() {
+		t.Error("expected no selection on new state")
+	}
+}
+
+func TestClear(t *testing.T) {
+	s := NewState()
+	s.MouseDown = true
+	s.MouseDownItemIdx = 2
+	s.DragItemIdx = 3
+	s.ClickCount = 2
+	s.Clear()
+
+	if s.MouseDown {
+		t.Error("expected MouseDown false after clear")
+	}
+	if s.MouseDownItemIdx != -1 {
+		t.Errorf("expected MouseDownItemIdx -1 after clear, got %d", s.MouseDownItemIdx)
+	}
+	if s.DragItemIdx != -1 {
+		t.Errorf("expected DragItemIdx -1 after clear, got %d", s.DragItemIdx)
+	}
+	if s.ClickCount != 0 {
+		t.Errorf("expected ClickCount 0 after clear, got %d", s.ClickCount)
+	}
+}
+
+func TestGetRange_Forward(t *testing.T) {
+	s := NewState()
+	s.MouseDownItemIdx = 0
+	s.MouseDownLineIdx = 1
+	s.MouseDownCol = 5
+	s.DragItemIdx = 0
+	s.DragLineIdx = 3
+	s.DragCol = 10
+
+	r := s.GetRange()
+	if r.StartItemIdx != 0 || r.StartLine != 1 || r.StartCol != 5 {
+		t.Errorf("unexpected start: item=%d line=%d col=%d", r.StartItemIdx, r.StartLine, r.StartCol)
+	}
+	if r.EndItemIdx != 0 || r.EndLine != 3 || r.EndCol != 10 {
+		t.Errorf("unexpected end: item=%d line=%d col=%d", r.EndItemIdx, r.EndLine, r.EndCol)
+	}
+}
+
+func TestGetRange_Backward(t *testing.T) {
+	s := NewState()
+	s.MouseDownItemIdx = 2
+	s.MouseDownLineIdx = 5
+	s.MouseDownCol = 20
+	s.DragItemIdx = 0
+	s.DragLineIdx = 1
+	s.DragCol = 3
+
+	r := s.GetRange()
+	// Should be normalized: drag position becomes start
+	if r.StartItemIdx != 0 || r.StartLine != 1 || r.StartCol != 3 {
+		t.Errorf("unexpected start: item=%d line=%d col=%d", r.StartItemIdx, r.StartLine, r.StartCol)
+	}
+	if r.EndItemIdx != 2 || r.EndLine != 5 || r.EndCol != 20 {
+		t.Errorf("unexpected end: item=%d line=%d col=%d", r.EndItemIdx, r.EndLine, r.EndCol)
+	}
+}
+
+func TestGetRange_SameLine(t *testing.T) {
+	s := NewState()
+	s.MouseDownItemIdx = 1
+	s.MouseDownLineIdx = 2
+	s.MouseDownCol = 10
+	s.DragItemIdx = 1
+	s.DragLineIdx = 2
+	s.DragCol = 20
+
+	r := s.GetRange()
+	if r.IsEmpty() {
+		t.Error("expected non-empty range")
+	}
+	if r.StartCol != 10 || r.EndCol != 20 {
+		t.Errorf("expected cols 10-20, got %d-%d", r.StartCol, r.EndCol)
+	}
+}
+
+func TestRangeIsEmpty(t *testing.T) {
+	// Same point
+	r := Range{StartItemIdx: 0, StartLine: 0, StartCol: 5, EndItemIdx: 0, EndLine: 0, EndCol: 5}
+	if !r.IsEmpty() {
+		t.Error("expected same-point range to be empty")
+	}
+
+	// Negative item idx
+	r = Range{StartItemIdx: -1, EndItemIdx: -1}
+	if !r.IsEmpty() {
+		t.Error("expected negative item idx range to be empty")
+	}
+
+	// Valid range
+	r = Range{StartItemIdx: 0, StartLine: 0, StartCol: 0, EndItemIdx: 0, EndLine: 0, EndCol: 5}
+	if r.IsEmpty() {
+		t.Error("expected valid range to not be empty")
+	}
+}
+
+func TestHasSelection(t *testing.T) {
+	s := NewState()
+	if s.HasSelection() {
+		t.Error("new state should have no selection")
+	}
+
+	// Set up a valid selection
+	s.MouseDownItemIdx = 0
+	s.MouseDownLineIdx = 0
+	s.MouseDownCol = 0
+	s.DragItemIdx = 0
+	s.DragLineIdx = 0
+	s.DragCol = 10
+	if !s.HasSelection() {
+		t.Error("expected selection to exist")
+	}
+
+	// Same point = no selection
+	s.DragCol = 0
+	if s.HasSelection() {
+		t.Error("same point should not be a selection")
+	}
+}
+
+func TestIsLineInRange_SingleItem_SingleLine(t *testing.T) {
+	r := Range{
+		StartItemIdx: 1, StartLine: 2, StartCol: 5,
+		EndItemIdx: 1, EndLine: 2, EndCol: 15,
+	}
+
+	// Exact line
+	ok, sc, ec := IsLineInRange(r, 1, 2)
+	if !ok || sc != 5 || ec != 15 {
+		t.Errorf("expected (true, 5, 15), got (%v, %d, %d)", ok, sc, ec)
+	}
+
+	// Wrong line
+	ok, _, _ = IsLineInRange(r, 1, 0)
+	if ok {
+		t.Error("line 0 should not be in range")
+	}
+
+	// Wrong item
+	ok, _, _ = IsLineInRange(r, 0, 2)
+	if ok {
+		t.Error("item 0 should not be in range")
+	}
+}
+
+func TestIsLineInRange_SingleItem_MultiLine(t *testing.T) {
+	r := Range{
+		StartItemIdx: 0, StartLine: 1, StartCol: 5,
+		EndItemIdx: 0, EndLine: 4, EndCol: 10,
+	}
+
+	// Start line
+	ok, sc, ec := IsLineInRange(r, 0, 1)
+	if !ok || sc != 5 || ec != -1 {
+		t.Errorf("start line: expected (true, 5, -1), got (%v, %d, %d)", ok, sc, ec)
+	}
+
+	// Middle line
+	ok, sc, ec = IsLineInRange(r, 0, 2)
+	if !ok || sc != -1 || ec != -1 {
+		t.Errorf("middle line: expected (true, -1, -1), got (%v, %d, %d)", ok, sc, ec)
+	}
+
+	// End line
+	ok, sc, ec = IsLineInRange(r, 0, 4)
+	if !ok || sc != 0 || ec != 10 {
+		t.Errorf("end line: expected (true, 0, 10), got (%v, %d, %d)", ok, sc, ec)
+	}
+}
+
+func TestIsLineInRange_MultiItem(t *testing.T) {
+	r := Range{
+		StartItemIdx: 0, StartLine: 3, StartCol: 5,
+		EndItemIdx: 2, EndLine: 1, EndCol: 10,
+	}
+
+	// First item, start line
+	ok, sc, ec := IsLineInRange(r, 0, 3)
+	if !ok || sc != 5 || ec != -1 {
+		t.Errorf("first item start: expected (true, 5, -1), got (%v, %d, %d)", ok, sc, ec)
+	}
+
+	// First item, line after start
+	ok, sc, ec = IsLineInRange(r, 0, 5)
+	if !ok || sc != -1 || ec != -1 {
+		t.Errorf("first item after: expected (true, -1, -1), got (%v, %d, %d)", ok, sc, ec)
+	}
+
+	// Middle item, any line
+	ok, sc, ec = IsLineInRange(r, 1, 0)
+	if !ok || sc != -1 || ec != -1 {
+		t.Errorf("middle item: expected (true, -1, -1), got (%v, %d, %d)", ok, sc, ec)
+	}
+
+	// Last item, end line
+	ok, sc, ec = IsLineInRange(r, 2, 1)
+	if !ok || sc != 0 || ec != 10 {
+		t.Errorf("last item end: expected (true, 0, 10), got (%v, %d, %d)", ok, sc, ec)
+	}
+
+	// Last item, line after end
+	ok, _, _ = IsLineInRange(r, 2, 5)
+	if ok {
+		t.Error("line after end in last item should not be in range")
+	}
+}
+
+func TestFindWordBoundaries(t *testing.T) {
+	tests := []struct {
+		name      string
+		line      string
+		col       int
+		wantStart int
+		wantEnd   int
+	}{
+		{
+			name:      "simple word",
+			line:      "hello world",
+			col:       2,
+			wantStart: 0,
+			wantEnd:   5,
+		},
+		{
+			name:      "second word",
+			line:      "hello world",
+			col:       7,
+			wantStart: 6,
+			wantEnd:   11,
+		},
+		{
+			name:      "on space",
+			line:      "hello world",
+			col:       5,
+			wantStart: 5,
+			wantEnd:   5,
+		},
+		{
+			name:      "empty line",
+			line:      "",
+			col:       0,
+			wantStart: 0,
+			wantEnd:   0,
+		},
+		{
+			name:      "negative col",
+			line:      "hello",
+			col:       -1,
+			wantStart: 0,
+			wantEnd:   0,
+		},
+		{
+			name:      "past end",
+			line:      "hello",
+			col:       10,
+			wantStart: 10,
+			wantEnd:   10,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			start, end := FindWordBoundaries(tt.line, tt.col)
+			if start != tt.wantStart || end != tt.wantEnd {
+				t.Errorf("FindWordBoundaries(%q, %d) = (%d, %d), want (%d, %d)",
+					tt.line, tt.col, start, end, tt.wantStart, tt.wantEnd)
+			}
+		})
+	}
+}
+
+func TestExtractText_PlainText(t *testing.T) {
+	line := "Hello, World!"
+	text := ExtractText(line, 0, 5)
+	if text != "Hello" {
+		t.Errorf("expected 'Hello', got %q", text)
+	}
+
+	text = ExtractText(line, 7, 12)
+	if text != "World" {
+		t.Errorf("expected 'World', got %q", text)
+	}
+}
+
+func TestExtractText_FullLine(t *testing.T) {
+	line := "Hello"
+	text := ExtractText(line, -1, -1)
+	if text != "Hello" {
+		t.Errorf("expected 'Hello', got %q", text)
+	}
+}
+
+func TestExtractText_Empty(t *testing.T) {
+	text := ExtractText("", 0, 5)
+	if text != "" {
+		t.Errorf("expected empty string, got %q", text)
+	}
+}
+
+func TestExtractText_OutOfBounds(t *testing.T) {
+	line := "Hi"
+	text := ExtractText(line, 5, 10)
+	if text != "" {
+		t.Errorf("expected empty string for out of bounds, got %q", text)
+	}
+}
+
+func TestHighlightLine_PlainText(t *testing.T) {
+	line := "Hello, World!"
+	result := HighlightLine(line, 0, 5)
+	// Should produce a non-empty result different from input (has ANSI codes)
+	if result == "" {
+		t.Error("expected non-empty result")
+	}
+	// Should still contain the text content
+	if len(result) < len(line) {
+		t.Error("result should be at least as long as input (ANSI codes add length)")
+	}
+}
+
+func TestHighlightLine_Empty(t *testing.T) {
+	result := HighlightLine("", 0, 5)
+	if result != "" {
+		t.Errorf("expected empty for empty input, got %q", result)
+	}
+}
+
+func TestHighlightLine_NoSelection(t *testing.T) {
+	line := "Hello"
+	result := HighlightLine(line, 3, 3)
+	// Same startCol and endCol = no change
+	if result != line {
+		t.Errorf("expected no change for zero-width selection, got %q", result)
+	}
+}
+
+// TestMultiClickDetection verifies the click counting logic.
+func TestMultiClickDetection(t *testing.T) {
+	s := NewState()
+	now := time.Now()
+
+	// First click
+	s.LastClickTime = now
+	s.LastClickX = 10
+	s.LastClickY = 5
+	s.ClickCount = 1
+
+	// Second click within threshold
+	later := now.Add(200 * time.Millisecond)
+	if later.Sub(s.LastClickTime) <= DoubleClickThreshold {
+		if abs(10-s.LastClickX) <= ClickTolerance && abs(5-s.LastClickY) <= ClickTolerance {
+			s.ClickCount++
+		}
+	}
+	if s.ClickCount != 2 {
+		t.Errorf("expected click count 2, got %d", s.ClickCount)
+	}
+
+	// Third click
+	s.LastClickTime = later
+	later2 := later.Add(200 * time.Millisecond)
+	if later2.Sub(s.LastClickTime) <= DoubleClickThreshold {
+		if abs(10-s.LastClickX) <= ClickTolerance && abs(5-s.LastClickY) <= ClickTolerance {
+			s.ClickCount++
+		}
+	}
+	if s.ClickCount != 3 {
+		t.Errorf("expected click count 3, got %d", s.ClickCount)
+	}
+}
+
+func abs(x int) int {
+	if x < 0 {
+		return -x
+	}
+	return x
+}

internal/ui/session_selector.go

@@ -12,6 +12,7 @@ import (
 	"charm.land/lipgloss/v2"
 
 	"github.com/mark3labs/kit/internal/session"
+	"github.com/mark3labs/kit/internal/ui/style"
 )
 
 // SessionSelectedMsg is sent when the user selects a session from the picker.
@@ -158,12 +159,12 @@ func (ss *SessionSelectorComponent) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		}
 
 		switch {
-		case key.Matches(msg, key.NewBinding(key.WithKeys("up", "k"))):
+		case key.Matches(msg, key.NewBinding(key.WithKeys("up"))):
 			if ss.cursor > 0 {
 				ss.cursor--
 			}
 
-		case key.Matches(msg, key.NewBinding(key.WithKeys("down", "j"))):
+		case key.Matches(msg, key.NewBinding(key.WithKeys("down"))):
 			if ss.cursor < len(ss.filtered)-1 {
 				ss.cursor++
 			}
@@ -250,58 +251,108 @@ func (ss *SessionSelectorComponent) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 
 // View implements tea.Model.
 func (ss *SessionSelectorComponent) View() tea.View {
-	theme := GetTheme()
-	w := ss.width
-	var b strings.Builder
+	theme := style.GetTheme()
+
+	// Full-screen bordered container - uses entire terminal width and height
+	maxWidth := ss.width - 2 // Small margin on each side
+	if maxWidth < 20 {
+		maxWidth = ss.width
+	}
+	maxHeight := ss.height - 2 // Small margin top/bottom to prevent overflow
+	if maxHeight < 10 {
+		maxHeight = ss.height
+	}
+	horizontalPadding := 1
+	innerWidth := maxWidth - 4   // Account for border (2) + padding (2)
+	innerHeight := maxHeight - 4 // Account for border (2) + padding (2)
+
+	// Container style with border - full width/height like a framed panel
+	containerStyle := lipgloss.NewStyle().
+		Border(lipgloss.RoundedBorder()).
+		BorderForeground(theme.Primary).
+		Background(theme.Background).
+		Padding(1, horizontalPadding).
+		Width(maxWidth).
+		Height(maxHeight)
+
+	var contentBuilder strings.Builder
 
 	// ── Header: title + scope badges ─────────────────────────────
-	titleStyle := lipgloss.NewStyle().Bold(true).Foreground(theme.Accent).PaddingLeft(1)
-	b.WriteString(titleStyle.Render(fmt.Sprintf("Resume Session (%s)", ss.scope)))
-	b.WriteString("\n")
+	titleStyle := lipgloss.NewStyle().
+		Bold(true).
+		Foreground(theme.Accent).
+		Background(theme.Background)
+	contentBuilder.WriteString(titleStyle.Render(fmt.Sprintf("Resume Session (%s)", ss.scope)))
+	contentBuilder.WriteString("\n")
 
 	// ── Help / keybindings ───────────────────────────────────────
-	helpStyle := lipgloss.NewStyle().Foreground(theme.Muted).PaddingLeft(1)
-	if w >= 75 {
-		b.WriteString(helpStyle.Render("tab: scope  N: named  D: delete  R: rename  type to search  esc: cancel"))
-	} else if w >= 50 {
-		b.WriteString(helpStyle.Render("tab scope  N named  D del  type to search  esc"))
+	helpStyle := lipgloss.NewStyle().
+		Foreground(theme.Muted).
+		Background(theme.Background)
+	if innerWidth >= 75 {
+		contentBuilder.WriteString(helpStyle.Render("tab: scope  N: named  D: delete  R: rename  type to search  esc: cancel"))
+	} else if innerWidth >= 50 {
+		contentBuilder.WriteString(helpStyle.Render("tab scope  N named  D del  type to search  esc"))
 	} else {
-		b.WriteString(helpStyle.Render("tab N D esc"))
+		contentBuilder.WriteString(helpStyle.Render("tab N D esc"))
 	}
-	b.WriteString("\n")
+	contentBuilder.WriteString("\n")
 
 	// ── Search (only shown when active) ──────────────────────────
 	if ss.search != "" {
-		searchStyle := lipgloss.NewStyle().Foreground(theme.Info).PaddingLeft(1)
-		b.WriteString(searchStyle.Render(fmt.Sprintf("> %s", ss.search)))
-		b.WriteString("\n")
+		searchStyle := lipgloss.NewStyle().
+			Foreground(theme.Info).
+			Background(theme.Background)
+		contentBuilder.WriteString(searchStyle.Render(fmt.Sprintf("> %s", ss.search)))
+		contentBuilder.WriteString("\n")
 	}
 
-	b.WriteString("\n")
+	// Separator line
+	sepWidth := innerWidth
+	contentBuilder.WriteString(
+		lipgloss.NewStyle().
+			Foreground(theme.Muted).
+			Background(theme.Background).
+			Render(strings.Repeat("─", sepWidth)))
+	contentBuilder.WriteString("\n")
 
 	// ── Delete confirmation ──────────────────────────────────────
 	if ss.confirmDelete >= 0 && ss.confirmDelete < len(ss.filtered) {
-		warnStyle := lipgloss.NewStyle().Foreground(theme.Error).Bold(true).PaddingLeft(1)
+		warnStyle := lipgloss.NewStyle().
+			Foreground(theme.Error).
+			Bold(true).
+			Background(theme.Background)
 		name := sessionDisplayName(ss.filtered[ss.confirmDelete])
-		b.WriteString(warnStyle.Render(fmt.Sprintf("Delete %q? (y/N)", truncateRunes(name, 40))))
-		b.WriteString("\n")
+		contentBuilder.WriteString(warnStyle.Render(fmt.Sprintf("Delete %q? (y/N)", truncateRunes(name, 40))))
+		contentBuilder.WriteString("\n")
 	}
 
 	// ── Session list ─────────────────────────────────────────────
 	if len(ss.filtered) == 0 {
-		emptyStyle := lipgloss.NewStyle().Foreground(theme.Muted).PaddingLeft(2)
+		emptyStyle := lipgloss.NewStyle().
+			Foreground(theme.Muted).
+			Background(theme.Background)
 		if ss.search != "" {
-			b.WriteString(emptyStyle.Render(fmt.Sprintf("No sessions matching %q", ss.search)))
+			contentBuilder.WriteString(emptyStyle.Render(fmt.Sprintf("No sessions matching %q", ss.search)))
 		} else if ss.filter == SessionFilterNamed {
-			b.WriteString(emptyStyle.Render("No named sessions. Press N to show all."))
+			contentBuilder.WriteString(emptyStyle.Render("No named sessions. Press N to show all."))
 		} else if ss.scope == SessionScopeCwd {
-			b.WriteString(emptyStyle.Render("No sessions in current folder. Press tab to view all."))
+			contentBuilder.WriteString(emptyStyle.Render("No sessions in current folder. Press tab to view all."))
 		} else {
-			b.WriteString(emptyStyle.Render("No sessions found"))
+			contentBuilder.WriteString(emptyStyle.Render("No sessions found"))
 		}
-		b.WriteString("\n")
+		contentBuilder.WriteString("\n")
 	} else {
-		visH := ss.visibleHeight()
+		// Compute visible window based on inner container height
+		// Chrome: header(2) + separator(1) + footer separator(1) + footer(1) = 5
+		chromeLines := 5
+		if ss.search != "" {
+			chromeLines++
+		}
+		if ss.confirmDelete >= 0 {
+			chromeLines++
+		}
+		visH := max(innerHeight-chromeLines, 3)
 
 		// Center the cursor in the visible window.
 		startIdx := max(0, min(ss.cursor-visH/2, len(ss.filtered)-visH))
@@ -312,20 +363,42 @@ func (ss *SessionSelectorComponent) View() tea.View {
 			isCursor := i == ss.cursor
 			isCurrent := info.Path == ss.currentPath
 			isDeleting := i == ss.confirmDelete
-			line := ss.renderEntry(info, isCursor, isCurrent, isDeleting, w)
-			b.WriteString(line)
-			b.WriteString("\n")
+			line := ss.renderEntry(info, isCursor, isCurrent, isDeleting, innerWidth)
+			contentBuilder.WriteString(line)
+			contentBuilder.WriteString("\n")
 		}
 
 		// Scroll position indicator.
 		if len(ss.filtered) > visH {
-			posStyle := lipgloss.NewStyle().Foreground(theme.Muted).PaddingLeft(2)
-			b.WriteString(posStyle.Render(fmt.Sprintf("(%d/%d)", ss.cursor+1, len(ss.filtered))))
-			b.WriteString("\n")
+			posStyle := lipgloss.NewStyle().
+				Foreground(theme.Muted).
+				Background(theme.Background)
+			contentBuilder.WriteString(posStyle.Render(fmt.Sprintf("(%d/%d)", ss.cursor+1, len(ss.filtered))))
+			contentBuilder.WriteString("\n")
 		}
 	}
 
-	return tea.NewView(b.String())
+	// Footer separator
+	contentBuilder.WriteString(
+		lipgloss.NewStyle().
+			Foreground(theme.Muted).
+			Background(theme.Background).
+			Render(strings.Repeat("─", sepWidth)))
+	contentBuilder.WriteString("\n")
+
+	// Footer with filter info
+	footerStyle := lipgloss.NewStyle().
+		Foreground(theme.Muted).
+		Background(theme.Background)
+	contentBuilder.WriteString(footerStyle.Render(fmt.Sprintf("Filter: %s", ss.filter)))
+
+	// Apply the bordered container
+	content := contentBuilder.String()
+	borderedContent := containerStyle.Render(content)
+
+	v := tea.NewView(borderedContent)
+	v.AltScreen = true
+	return v
 }
 
 // IsActive returns whether the selector is still accepting input.
@@ -403,12 +476,12 @@ func removeByPath(sessions []session.SessionInfo, path string) []session.Session
 // renderEntry renders a single session line with right-aligned metadata.
 // Layout: [cursor 2] [message ...variable...] [padding] [count age] [cwd?]
 func (ss *SessionSelectorComponent) renderEntry(info session.SessionInfo, isCursor, isCurrent, isDeleting bool, width int) string {
-	theme := GetTheme()
+	theme := style.GetTheme()
 
 	// ── Cursor indicator (2 chars) ───────────────────────────────
 	cursorStr := "  "
 	if isCursor {
-		cursorStr = lipgloss.NewStyle().Foreground(theme.Accent).Render("› ")
+		cursorStr = lipgloss.NewStyle().Foreground(theme.Accent).Render("> ")
 	}
 	const cursorW = 2
 
@@ -436,45 +509,50 @@ func (ss *SessionSelectorComponent) renderEntry(info session.SessionInfo, isCurs
 	msgW := utf8.RuneCountInString(displayText)
 
 	// ── Style the message ────────────────────────────────────────
-	msgStyle := lipgloss.NewStyle()
+	var msgStyle lipgloss.Style
 	switch {
 	case isDeleting:
-		msgStyle = msgStyle.Foreground(theme.Error)
+		msgStyle = lipgloss.NewStyle().Foreground(theme.Error)
 	case isCurrent:
-		msgStyle = msgStyle.Foreground(theme.Accent)
+		msgStyle = lipgloss.NewStyle().Foreground(theme.Accent)
 	case info.Name != "":
-		msgStyle = msgStyle.Foreground(theme.Warning)
+		msgStyle = lipgloss.NewStyle().Foreground(theme.Warning)
 	default:
-		msgStyle = msgStyle.Foreground(theme.Text)
+		msgStyle = lipgloss.NewStyle().Foreground(theme.Text)
 	}
-	if isCursor {
-		msgStyle = msgStyle.Bold(true)
-	}
-
-	styledMsg := msgStyle.Render(displayText)
 
 	// ── Style the right part ─────────────────────────────────────
 	rightColor := theme.Muted
 	if isDeleting {
 		rightColor = theme.Error
 	}
-	styledRight := lipgloss.NewStyle().Foreground(rightColor).Render(rightPart)
+	var styledRight string
 
 	// ── Assemble with spacing ────────────────────────────────────
 	spacing := max(width-cursorW-msgW-rightW, 1)
 
-	line := cursorStr + styledMsg + strings.Repeat(" ", spacing) + styledRight
-
-	// ── Background highlight for selected row ────────────────────
+	// If selected, use inverted colors like PopupList
 	if isCursor {
-		// Use a subtle background highlight. We apply it by wrapping the
-		// full line in a style with a background color.
-		bgStyle := lipgloss.NewStyle().
-			Background(theme.Highlight).
-			Width(width)
-		line = bgStyle.Render(line)
+		// Inverted colors for selected item
+		msgStyle = lipgloss.NewStyle().
+			Background(theme.Primary).
+			Foreground(theme.Background).
+			Bold(true)
+		styledRight = lipgloss.NewStyle().
+			Background(theme.Primary).
+			Foreground(rightColor).
+			Render(rightPart)
+		cursorStr = lipgloss.NewStyle().
+			Background(theme.Primary).
+			Foreground(theme.Accent).
+			Render("> ")
+	} else {
+		styledRight = lipgloss.NewStyle().Foreground(rightColor).Render(rightPart)
 	}
 
+	styledMsg := msgStyle.Render(displayText)
+	line := cursorStr + styledMsg + strings.Repeat(" ", spacing) + styledRight
+
 	return line
 }
 

internal/ui/slash_command_input.go

@@ -1,352 +0,0 @@
-package ui
-
-import (
-	"strings"
-
-	"charm.land/bubbles/v2/key"
-	"charm.land/bubbles/v2/textarea"
-	tea "charm.land/bubbletea/v2"
-	"charm.land/lipgloss/v2"
-)
-
-// SlashCommandInput provides an interactive text input field with intelligent
-// slash command autocomplete functionality. It displays a popup menu of matching
-// commands as the user types, supporting fuzzy matching and keyboard navigation.
-type SlashCommandInput struct {
-	textarea      textarea.Model
-	commands      []SlashCommand
-	showPopup     bool
-	filtered      []FuzzyMatch
-	selected      int
-	width         int
-	lastValue     string
-	popupHeight   int
-	title         string
-	quitting      bool
-	value         string
-	submitNext    bool // Flag to submit on next update
-	renderedLines int  // Track how many lines were rendered
-	hideHint      bool // Suppress the "enter submit · ctrl+j..." hint
-}
-
-// NewSlashCommandInput creates and initializes a new slash command input field with
-// the specified width and title. The input supports multi-line text entry, command
-// autocomplete, and is styled to match the application's theme.
-func NewSlashCommandInput(width int, title string) *SlashCommandInput {
-	ta := textarea.New()
-	ta.Placeholder = "Type your message..."
-	ta.ShowLineNumbers = false
-	ta.Prompt = ""
-	ta.CharLimit = 5000
-	ta.SetWidth(width - 8) // Account for container padding, border and internal padding
-	ta.SetHeight(3)        // Default to 3 lines like huh
-	ta.Focus()
-
-	// Override InsertNewline so only ctrl+j and shift+enter insert newlines.
-	// Enter always submits the input.
-	ta.KeyMap.InsertNewline = key.NewBinding(
-		key.WithKeys("ctrl+j", "shift+enter"),
-		key.WithHelp("ctrl+j", "insert newline"),
-	)
-
-	// Style the textarea using theme colors.
-	theme := GetTheme()
-	styles := ta.Styles()
-	styles.Focused.Base = lipgloss.NewStyle()
-	styles.Focused.Placeholder = lipgloss.NewStyle().Foreground(theme.VeryMuted)
-	styles.Focused.Text = lipgloss.NewStyle().Foreground(theme.Text)
-	styles.Focused.Prompt = lipgloss.NewStyle()
-	styles.Focused.CursorLine = lipgloss.NewStyle()
-	ta.SetStyles(styles)
-
-	return &SlashCommandInput{
-		textarea:    ta,
-		commands:    SlashCommands,
-		width:       width,
-		popupHeight: 7,
-		title:       title,
-	}
-}
-
-// Init implements the tea.Model interface, returning the initial command to start
-// the cursor blinking animation for the text input field.
-func (s *SlashCommandInput) Init() tea.Cmd {
-	return textarea.Blink
-}
-
-// Update implements the tea.Model interface, handling keyboard input for text entry,
-// command selection, and navigation. Manages the autocomplete popup display and
-// processes submission or cancellation actions.
-func (s *SlashCommandInput) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
-	var cmd tea.Cmd
-
-	// Check if we need to submit after updating the view
-	if s.submitNext {
-		s.value = s.textarea.Value()
-		s.quitting = true
-		return s, tea.Quit
-	}
-
-	switch msg := msg.(type) {
-	case tea.KeyPressMsg: // Check for quit keys first (when popup is not shown)
-		if !s.showPopup {
-			switch msg.String() {
-			case "ctrl+c", "esc":
-				s.quitting = true
-				return s, tea.Quit
-			case "ctrl+d", "enter": // Enter always submits
-				s.value = s.textarea.Value()
-				s.quitting = true
-				return s, tea.Quit
-			}
-		}
-
-		// Handle popup navigation
-		if s.showPopup {
-			switch {
-			case key.Matches(msg, key.NewBinding(key.WithKeys("up"), key.WithHelp("↑", "up"))):
-				if s.selected > 0 {
-					s.selected--
-				}
-				return s, nil
-			case key.Matches(msg, key.NewBinding(key.WithKeys("down"), key.WithHelp("↓", "down"))):
-				if s.selected < len(s.filtered)-1 {
-					s.selected++
-				}
-				return s, nil
-			case key.Matches(msg, key.NewBinding(key.WithKeys("tab"))):
-				if s.selected < len(s.filtered) {
-					// Complete with selected command
-					s.textarea.SetValue(s.filtered[s.selected].Command.Name)
-					s.showPopup = false
-					s.selected = 0
-					// Move cursor to end
-					s.textarea.CursorEnd()
-				}
-				return s, nil
-			case key.Matches(msg, key.NewBinding(key.WithKeys("enter"))):
-				if s.selected < len(s.filtered) {
-					// Populate the field with the selected command
-					s.textarea.SetValue(s.filtered[s.selected].Command.Name)
-					s.textarea.CursorEnd()
-					// Hide the popup
-					s.showPopup = false
-					s.selected = 0
-					// Set flag to submit on next update (after view refresh)
-					s.submitNext = true
-					// Force a refresh
-					return s, nil
-				}
-				return s, nil
-			case key.Matches(msg, key.NewBinding(key.WithKeys("esc"))):
-				s.showPopup = false
-				s.selected = 0
-				return s, nil
-			}
-		}
-
-		// Update textarea
-		s.textarea, cmd = s.textarea.Update(msg)
-
-		// Check if we should show/update popup
-		value := s.textarea.Value()
-		if value != s.lastValue {
-			s.lastValue = value
-			// Only show popup if we're on the first line and it starts with /
-			lines := strings.Split(value, "\n")
-			if len(lines) > 0 && strings.HasPrefix(lines[0], "/") && !strings.Contains(lines[0], " ") && len(lines) == 1 {
-				// Show and update popup
-				s.showPopup = true
-				s.filtered = FuzzyMatchCommands(lines[0], s.commands)
-				s.selected = 0
-			} else {
-				// Hide popup
-				s.showPopup = false
-			}
-		}
-		return s, cmd
-
-	default:
-		// Pass through other messages
-		s.textarea, cmd = s.textarea.Update(msg)
-		return s, cmd
-	}
-}
-
-// View implements the tea.Model interface, rendering the complete input field
-// including the title, text area, autocomplete popup (when active), and help text.
-// The view adapts based on whether single or multi-line input is detected.
-func (s *SlashCommandInput) View() tea.View {
-	containerStyle := lipgloss.NewStyle()
-
-	theme := GetTheme()
-
-	// PaddingLeft(3) aligns with message content: border(1) + paddingLeft(2).
-	titleStyle := lipgloss.NewStyle().
-		Foreground(theme.Text).
-		MarginBottom(1).
-		PaddingLeft(3)
-
-	// Input box with huh-like styling
-	inputBoxStyle := lipgloss.NewStyle().
-		Border(lipgloss.ThickBorder()).
-		BorderLeft(true).
-		BorderRight(false).
-		BorderTop(false).
-		BorderBottom(false).
-		BorderForeground(theme.Primary).
-		PaddingLeft(2).    // match message block paddingLeft
-		Width(s.width - 1) // full width minus left border
-
-	// Build the view
-	var view strings.Builder
-	view.WriteString(titleStyle.Render(s.title))
-	view.WriteString("\n")
-	view.WriteString(inputBoxStyle.Render(s.textarea.View()))
-	// Count rendered lines
-	s.renderedLines = 2 + s.textarea.Height() // title + newline + textarea height
-
-	// Add popup if visible
-	if s.showPopup && len(s.filtered) > 0 {
-		view.WriteString("\n")
-		view.WriteString(s.renderPopup())
-		// Add popup lines
-		visibleItems := min(len(s.filtered), s.popupHeight)
-		scrollIndicators := 0
-		if s.selected >= s.popupHeight {
-			scrollIndicators++ // top indicator
-		}
-		if len(s.filtered) > s.popupHeight {
-			scrollIndicators++ // bottom indicator
-		}
-		popupLines := visibleItems + scrollIndicators + 5 // items + scroll + border + padding + footer
-		s.renderedLines += 1 + popupLines                 // newline + popup
-	}
-
-	// Add help text at bottom (unless hidden by extension).
-	if !s.hideHint {
-		helpStyle := lipgloss.NewStyle().
-			Foreground(theme.VeryMuted).
-			MarginTop(1).
-			PaddingLeft(3)
-
-		helpText := "enter submit • ctrl+j / shift+enter new line"
-
-		view.WriteString("\n")
-		view.WriteString(helpStyle.Render(helpText))
-		s.renderedLines += 2 // newline + help text
-	}
-
-	// Apply container padding to entire view
-	return tea.NewView(containerStyle.Render(view.String()))
-}
-
-// renderPopup renders the autocomplete popup
-func (s *SlashCommandInput) renderPopup() string {
-	theme := GetTheme()
-
-	// Popup styling
-	popupStyle := lipgloss.NewStyle().
-		Border(lipgloss.RoundedBorder()).
-		BorderForeground(theme.MutedBorder).
-		Padding(1, 2).
-		Width(s.width - 4). // Account for container padding
-		MarginLeft(0)       // No extra margin needed due to container padding
-
-	var items []string
-
-	// Calculate visible window
-	visibleItems := min(len(s.filtered), s.popupHeight)
-	startIdx := 0
-
-	// Adjust window to keep selected item visible
-	if s.selected >= s.popupHeight {
-		startIdx = s.selected - s.popupHeight + 1
-	}
-
-	endIdx := min(startIdx+visibleItems, len(s.filtered))
-
-	for i := startIdx; i < endIdx; i++ {
-		match := s.filtered[i]
-		cmd := match.Command
-		// Create the selection indicator
-		var indicator string
-		if i == s.selected {
-			indicator = lipgloss.NewStyle().
-				Foreground(theme.Primary).
-				Render("> ")
-		} else {
-			indicator = "  "
-		}
-
-		// Format item
-		nameStyle := lipgloss.NewStyle().
-			Foreground(theme.Secondary).
-			Bold(true)
-
-		descStyle := lipgloss.NewStyle().
-			Foreground(theme.Muted)
-
-		// Highlight selected item
-		if i == s.selected {
-			nameStyle = nameStyle.Foreground(theme.Primary)
-			descStyle = descStyle.Foreground(theme.Text)
-		}
-
-		// Format with proper spacing
-		nameWidth := 15
-		name := nameStyle.Width(nameWidth - 2).Render(cmd.Name)
-
-		// Truncate description if needed
-		desc := cmd.Description
-		maxDescLen := s.width - nameWidth - 14 // Account for padding and indicator
-		if len(desc) > maxDescLen && maxDescLen > 3 {
-			desc = desc[:maxDescLen-3] + "..."
-		}
-
-		line := indicator + name + descStyle.Render(desc)
-		items = append(items, line)
-	}
-
-	// Add scroll indicators if needed
-	if startIdx > 0 {
-		scrollUpStyle := lipgloss.NewStyle().Foreground(theme.VeryMuted)
-		items = append([]string{scrollUpStyle.Render("  ↑ more above")}, items...)
-	}
-	if endIdx < len(s.filtered) {
-		scrollDownStyle := lipgloss.NewStyle().Foreground(theme.VeryMuted)
-		items = append(items, scrollDownStyle.Render("  ↓ more below"))
-	}
-	// Join items
-	content := strings.Join(items, "\n")
-
-	// Add footer hint
-	footerStyle := lipgloss.NewStyle().
-		Foreground(theme.VeryMuted).
-		Italic(true)
-	footer := footerStyle.Render("↑↓ navigate • tab complete • ↵ select • esc dismiss")
-
-	// Combine content and footer
-	popupContent := content + "\n\n" + footer
-
-	return popupStyle.Render(popupContent)
-}
-
-// Value returns the final text value entered by the user after submission.
-// This will be empty if the input was cancelled.
-func (s *SlashCommandInput) Value() string {
-	return s.value
-}
-
-// Cancelled returns true if the user cancelled the input operation (e.g., by
-// pressing ESC or Ctrl+C) without submitting any text.
-func (s *SlashCommandInput) Cancelled() bool {
-	return s.quitting && s.value == ""
-}
-
-// RenderedLines returns the total number of terminal lines used by the last
-// rendered view, including the title, input area, popup, and help text. This
-// is used for proper screen clearing when the input is dismissed.
-func (s *SlashCommandInput) RenderedLines() int {
-	return s.renderedLines
-}

internal/ui/stream.go

@@ -2,13 +2,27 @@ package ui
 
 import (
 	"fmt"
+	"regexp"
 	"strings"
 	"time"
 
 	tea "charm.land/bubbletea/v2"
 	"charm.land/lipgloss/v2"
 	"github.com/indaco/herald"
+
 	"github.com/mark3labs/kit/internal/app"
+	"github.com/mark3labs/kit/internal/ui/style"
+)
+
+// thinkTagRegex matches  ...  tags that some models (Qwen, DeepSeek) wrap
+// reasoning content in. Used to strip these tags from streaming text content.
+// The (?s) flag makes . match newlines.
+var thinkTagRegex = regexp.MustCompile(`(?s)` + `` + `think` + `` + `(.*?)` + `` + `/think` + ``)
+
+// thinkTagOpen and thinkTagClose are the opening and closing think tag strings.
+const (
+	thinkTagOpen  = "<think>"
+	thinkTagClose = "</think>"
 )
 
 // knightRiderFrames generates a KITT-style scanning animation where a bright
@@ -19,7 +33,7 @@ func knightRiderFrames() []string {
 	const numDots = 8
 	const dot = "▪"
 
-	theme := GetTheme()
+	theme := style.GetTheme()
 
 	bright := lipgloss.NewStyle().Foreground(theme.Primary)
 	med := lipgloss.NewStyle().Foreground(theme.Muted)
@@ -119,13 +133,13 @@ const (
 // alongside streaming text until the step completes and Reset() is called.
 //
 // Tool calls, tool results, user messages, and other non-streaming content
-// are printed immediately by the parent AppModel via tea.Println(). The
-// StreamComponent only handles the live streaming text and spinner display.
+// are added to the ScrollList by the parent AppModel. The StreamComponent
+// only handles the live streaming text and spinner display.
 //
 // Lifecycle is managed entirely by the parent AppModel:
 //   - Parent calls Reset() between agent steps to clear state.
-//   - Parent emits completed responses above the BT region via tea.Println()
-//     then calls Reset(); StreamComponent never calls tea.Quit.
+//   - Content is displayed via StreamingMessageItem in the ScrollList.
+//   - StreamComponent never calls tea.Quit.
 //
 // Events handled:
 //   - app.SpinnerEvent{Show:true}  → start spinner tick loop
@@ -184,15 +198,6 @@ type StreamComponent struct {
 	// ticks from a previous step can be discarded.
 	flushGeneration uint64
 
-	// renderCache holds the last rendered output string. Reused by View()
-	// between flush ticks to avoid redundant markdown re-parsing.
-	renderCache string
-
-	// renderDirty is true when committed content has changed since the
-	// last render. Set on flush tick; cleared after render() rebuilds
-	// the cache.
-	renderDirty bool
-
 	// thinkingVisible controls whether reasoning blocks are expanded or collapsed.
 	thinkingVisible bool
 
@@ -202,7 +207,11 @@ type StreamComponent struct {
 	// reasoningDuration holds the total reasoning time, frozen when streaming text begins.
 	reasoningDuration time.Duration
 
-	// renderer renders streaming assistant text in either compact or standard mode.
+	// inThinkTag tracks whether we're currently inside a  section
+	// from models that wrap reasoning in XML-like tags (Qwen, DeepSeek).
+	inThinkTag bool
+
+	// renderer renders streaming assistant text.
 	renderer Renderer
 
 	// modelName is displayed in the streaming text header.
@@ -223,17 +232,12 @@ type StreamComponent struct {
 }
 
 // NewStreamComponent creates a new StreamComponent ready to be embedded in AppModel.
-func NewStreamComponent(compactMode bool, width int, modelName string) *StreamComponent {
+func NewStreamComponent(width int, modelName string) *StreamComponent {
 	if width == 0 {
 		width = 80
 	}
 
-	var renderer Renderer
-	if compactMode {
-		renderer = NewCompactRenderer(width, false)
-	} else {
-		renderer = newMessageRenderer(width, false)
-	}
+	renderer := newMessageRenderer(width, false)
 
 	return &StreamComponent{
 		spinnerFrames: knightRiderFrames(),
@@ -253,9 +257,6 @@ func (s *StreamComponent) SetHeight(h int) {
 	}
 	if s.height != h {
 		s.height = h
-		// Invalidate cache — height clamp affects output.
-		s.renderCache = ""
-		s.renderDirty = true
 	}
 }
 
@@ -274,16 +275,20 @@ func (s *StreamComponent) Reset() {
 	s.pendingReasoning.Reset()
 	s.flushPending = false
 	s.flushGeneration++
-	s.renderCache = ""
-	s.renderDirty = false
 	s.timestamp = time.Time{}
 	s.reasoningStartTime = time.Time{}
 	s.reasoningDuration = 0
 }
 
+// ConsumeOverflow is a no-op in alt screen mode. Overflow is handled by the
+// ScrollList viewport. Retained to satisfy streamComponentIface.
+func (s *StreamComponent) ConsumeOverflow() string {
+	return ""
+}
+
 // GetRenderedContent returns the rendered assistant message from the accumulated
 // streaming text. Returns empty string if no text has been accumulated. Used by
-// the parent AppModel to flush content via tea.Println() before resetting.
+// the parent AppModel to flush stream content before resetting.
 //
 // This commits any pending chunks first so the output includes all received
 // content, not just what has been flushed by the tick.
@@ -311,17 +316,17 @@ func (s *StreamComponent) GetRenderedContent() string {
 }
 
 // commitPending moves any pending chunks to the committed content builders.
-// Called before reading content for scrollback output or on flush tick.
+// Called before reading content for output or on flush tick.
 func (s *StreamComponent) commitPending() {
 	if s.pendingStream.Len() > 0 {
-		s.streamContent.WriteString(s.pendingStream.String())
+		// Strip  ...  tags that some models wrap reasoning in
+		cleanedText := thinkTagRegex.ReplaceAllString(s.pendingStream.String(), "")
+		s.streamContent.WriteString(cleanedText)
 		s.pendingStream.Reset()
-		s.renderDirty = true
 	}
 	if s.pendingReasoning.Len() > 0 {
 		s.reasoningContent.WriteString(s.pendingReasoning.String())
 		s.pendingReasoning.Reset()
-		s.renderDirty = true
 	}
 }
 
@@ -344,9 +349,6 @@ func (s *StreamComponent) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		if s.renderer != nil {
 			s.renderer.SetWidth(s.width)
 		}
-		// Invalidate render cache — width change affects wrapping/styling.
-		s.renderCache = ""
-		s.renderDirty = true
 
 	case streamSpinnerTickMsg:
 		// Only continue the tick loop if this tick belongs to the current
@@ -399,6 +401,17 @@ func (s *StreamComponent) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			return s, streamFlushTickCmd(s.flushGeneration)
 		}
 
+	case app.ReasoningCompleteEvent:
+		// Freeze reasoning duration when reasoning finishes (before text streaming starts).
+		if s.reasoningDuration == 0 && !s.reasoningStartTime.IsZero() {
+			s.reasoningDuration = time.Since(s.reasoningStartTime)
+		}
+		// Flush any remaining pending reasoning content.
+		if s.pendingReasoning.Len() > 0 {
+			s.reasoningContent.WriteString(s.pendingReasoning.String())
+			s.pendingReasoning.Reset()
+		}
+
 	case app.StreamChunkEvent:
 		s.phase = streamPhaseActive
 		if s.timestamp.IsZero() {
@@ -408,8 +421,46 @@ func (s *StreamComponent) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		if s.reasoningDuration == 0 && !s.reasoningStartTime.IsZero() {
 			s.reasoningDuration = time.Since(s.reasoningStartTime)
 		}
-		s.pendingStream.WriteString(msg.Content)
-		if !s.flushPending {
+
+		// Handle models that wrap reasoning in  tags (Qwen, DeepSeek)
+		// Filter out all content between  and  tags
+		content := msg.Content
+
+		// Check for opening tag
+		if strings.Contains(content, thinkTagOpen) {
+			parts := strings.SplitN(content, thinkTagOpen, 2)
+			// Content before the tag can be written
+			if !s.inThinkTag && parts[0] != "" {
+				s.pendingStream.WriteString(parts[0])
+			}
+			s.inThinkTag = true
+			// Content after the opening tag is reasoning - don't write it
+			if len(parts) > 1 && parts[1] != "" {
+				// Check if the same chunk contains the closing tag
+				if strings.Contains(parts[1], thinkTagClose) {
+					innerParts := strings.SplitN(parts[1], thinkTagClose, 2)
+					s.inThinkTag = false
+					// Content after closing tag can be written
+					if len(innerParts) > 1 && innerParts[1] != "" {
+						s.pendingStream.WriteString(innerParts[1])
+					}
+				}
+			}
+		} else if strings.Contains(content, thinkTagClose) {
+			// Closing tag found
+			parts := strings.SplitN(content, thinkTagClose, 2)
+			s.inThinkTag = false
+			// Content after closing tag can be written
+			if len(parts) > 1 && parts[1] != "" {
+				s.pendingStream.WriteString(parts[1])
+			}
+		} else if !s.inThinkTag {
+			// Normal content, not inside think tags
+			s.pendingStream.WriteString(content)
+		}
+		// else: inside think tag, don't write this content
+
+		if !s.flushPending && s.pendingStream.Len() > 0 {
 			s.flushPending = true
 			return s, streamFlushTickCmd(s.flushGeneration)
 		}
@@ -448,72 +499,10 @@ func (s *StreamComponent) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	return s, nil
 }
 
-// View implements tea.Model. Renders the current stream region content.
+// View implements tea.Model. Returns an empty view since rendering is handled
+// by StreamingMessageItem in the ScrollList. Retained to satisfy tea.Model.
 func (s *StreamComponent) View() tea.View {
-	fullContent := s.render()
-	visibleContent := s.viewContent(fullContent)
-	return tea.NewView(visibleContent)
-}
-
-// --------------------------------------------------------------------------
-// Internal rendering
-// --------------------------------------------------------------------------
-
-// render builds the full content string for the stream region. Uses a render
-// cache to avoid redundant markdown re-parsing between flush ticks. The cache
-// is invalidated when committed content changes (flush tick), terminal width
-// changes, or height/thinking visibility changes.
-func (s *StreamComponent) render() string {
-	if s.phase == streamPhaseIdle {
-		return ""
-	}
-
-	// Return cached render if committed content hasn't changed.
-	if !s.renderDirty {
-		return s.renderCache
-	}
-
-	var sections []string
-
-	// Render reasoning/thinking block above the main text if present.
-	if reasoning := s.reasoningContent.String(); reasoning != "" {
-		sections = append(sections, s.renderReasoningBlock(reasoning))
-	}
-
-	// Render streaming text only. The spinner is rendered in the status bar
-	// by the parent so it never changes the stream region height.
-	text := s.streamContent.String()
-	if text != "" {
-		sections = append(sections, s.renderStreamingText(text))
-	}
-
-	if len(sections) == 0 {
-		s.renderCache = ""
-		s.renderDirty = false
-		return ""
-	}
-
-	content := strings.Join(sections, "\n")
-
-	// Cache FULL content without height clamping.
-	// Height clamping is applied in View() for display only.
-	s.renderCache = content
-	s.renderDirty = false
-	return content
-}
-
-// viewContent returns the visible portion of content based on height constraint.
-// This is called by View() to get the slice that fits in the terminal.
-func (s *StreamComponent) viewContent(fullContent string) string {
-	if s.height > 0 && fullContent != "" {
-		lines := strings.Split(fullContent, "\n")
-		if len(lines) > s.height {
-			// Keep only the last h lines so the most recent output is visible.
-			lines = lines[len(lines)-s.height:]
-			return strings.Join(lines, "\n")
-		}
-	}
-	return fullContent
+	return tea.NewView("")
 }
 
 // renderReasoningBlock renders the reasoning/thinking content using blockquote.
@@ -567,16 +556,13 @@ func (s *StreamComponent) renderReasoningBlock(reasoning string) string {
 	} else {
 		result = strings.Join(parts, "\n")
 	}
-	return lipgloss.NewStyle().MarginBottom(1).Render(result)
+	return styleMarginBottom1.Render(result)
 }
 
 // SetThinkingVisible sets whether reasoning blocks are shown or collapsed.
 func (s *StreamComponent) SetThinkingVisible(visible bool) {
 	if s.thinkingVisible != visible {
 		s.thinkingVisible = visible
-		// Invalidate cache — thinking visibility affects rendered output.
-		s.renderCache = ""
-		s.renderDirty = true
 	}
 }
 
@@ -650,10 +636,12 @@ func removeToolID(ids []string, id string) []string {
 }
 
 // formatToolExecutionMessage creates a descriptive spinner message for tool execution.
-// For spawn_subagent, it shows simply as "Subagent".
 func formatToolExecutionMessage(toolName string) string {
-	if toolName == "spawn_subagent" {
-		return "Subagent"
-	}
 	return toolName
 }
+
+// UpdateTheme refreshes the component's typography instance with colors from
+// the current theme. This is called when the user changes themes via /theme.
+func (s *StreamComponent) UpdateTheme() {
+	s.ty = createTypography(GetTheme())
+}

internal/ui/style/enhanced.go

@@ -1,4 +1,4 @@
-package ui
+package style
 
 import (
 	"fmt"
@@ -35,8 +35,11 @@ func GetTheme() Theme {
 
 // SetTheme updates the global UI theme, affecting all subsequent rendering
 // operations. This allows runtime theme switching for different visual preferences.
+// It also invalidates the markdownTypographyCache so the next call to
+// GetMarkdownTypography picks up the new theme.
 func SetTheme(theme Theme) {
 	currentTheme = theme
+	markdownTypographyCache = nil // invalidate cached renderer; colors may have changed
 }
 
 // MarkdownThemeColors defines colors for markdown rendering and syntax highlighting.
@@ -292,44 +295,27 @@ func ApplyGradient(text string, colorA, colorB color.Color) string {
 	return result.String()
 }
 
-// CreateGradientText creates styled text with a gradient effect between two colors.
-func CreateGradientText(text string, startColor, endColor color.Color) string {
-	return ApplyGradient(text, startColor, endColor)
-}
-
-// Compact styling utilities
-
-// StyleCompactSymbol creates a lipgloss style for message type indicators in
-// compact mode, using bold colored text to distinguish different message categories.
-func StyleCompactSymbol(symbol string, c color.Color) lipgloss.Style {
-	return lipgloss.NewStyle().
-		Foreground(c).
-		Bold(true)
-}
-
-// StyleCompactLabel creates a lipgloss style for message labels in compact mode
-// with fixed width for alignment and bold colored text for readability.
-func StyleCompactLabel(c color.Color) lipgloss.Style {
-	return lipgloss.NewStyle().
-		Foreground(c).
-		Bold(true).
-		Width(8)
-}
-
-// StyleCompactContent creates a simple lipgloss style for message content in
-// compact mode, applying only color without additional formatting.
-func StyleCompactContent(c color.Color) lipgloss.Style {
-	return lipgloss.NewStyle().
-		Foreground(c)
-}
-
-// FormatCompactLine assembles a complete compact mode message line with consistent
-// spacing and styling. Combines a symbol, fixed-width label, and content with their
-// respective colors to create a uniform appearance across all message types.
-func FormatCompactLine(symbol, label, content string, symbolColor, labelColor, contentColor color.Color) string {
-	styledSymbol := StyleCompactSymbol(symbol, symbolColor).Render(symbol)
-	styledLabel := StyleCompactLabel(labelColor).Render(label)
-	styledContent := StyleCompactContent(contentColor).Render(content)
-
-	return fmt.Sprintf("%s  %-8s %s", styledSymbol, styledLabel, styledContent)
+// KitBanner returns the KIT ASCII art title with KITT scanner lights,
+// rendered with a KITT red gradient.
+func KitBanner() string {
+	kittDark := lipgloss.Color("#8B0000")
+	kittBright := lipgloss.Color("#FF2200")
+	lines := []string{
+		"             ██╗  ██╗ ██╗ ████████╗",
+		"             ██║ ██╔╝ ██║ ╚══██╔══╝",
+		"             █████╔╝  ██║    ██║",
+		"             ██╔═██╗  ██║    ██║",
+		"             ██║  ██╗ ██║    ██║",
+		"             ╚═╝  ╚═╝ ╚═╝    ╚═╝",
+		"░░ ░░ ░░ ▒▒ ▒▒ ▓▓ ▓▓ ████ ▓▓ ▓▓ ▒▒ ▒▒ ░░ ░░ ░░",
+	}
+
+	var result strings.Builder
+	for i, line := range lines {
+		if i > 0 {
+			result.WriteString("\n")
+		}
+		result.WriteString(ApplyGradient(line, kittDark, kittBright))
+	}
+	return result.String()
 }