🐛 fix(desktop): detect bundled Codex CLI from Codex.app on macOS

The OpenAI Codex desktop app ships the real `codex` CLI inside its
`.app` bundle but does not symlink it onto PATH. Users who installed
only the desktop app therefore failed PATH-based detection, so the
heterogeneous agent never spawned Codex and silently produced no reply.

Probe the bundled binary as a fallback candidate (after the PATH lookup,
so a user's own install still wins), covering both system and per-user
install locations. macOS only for now.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/desktop/src/main/modules/toolDetectors/__tests__/cliAgentDetectors.test.ts

@@ -182,6 +182,42 @@ describe('cliAgentDetectors', () => {
       expect(execFileMock).toHaveBeenCalledTimes(2);
     });
 
+    it('falls back to the bundled Codex.app binary when `codex` is not on PATH', async () => {
+      // OpenAI's Codex desktop app ships the real CLI inside the .app but does
+      // not symlink it onto PATH. A user with only the desktop app installed
+      // has no `codex` on PATH, so detection must fall back to the bundle.
+      const originalShell = process.env.SHELL;
+      const originalPath = process.env.PATH;
+      // Unset SHELL and pin an already-normalized PATH so `resolveCommandPath`
+      // makes exactly one `which` attempt (no login-shell / normalized-PATH
+      // fallback retry), leaving the bundle as the only viable candidate.
+      delete process.env.SHELL;
+      process.env.PATH = '/usr/bin:/bin';
+
+      try {
+        // 1) `which codex` → not found
+        callExecFileError(new Error('not found'));
+        // 2) absolute bundle path resolves directly (no `which`); validate it
+        callExecFile('codex-cli 0.138.0-alpha.7');
+
+        const { codexDetector } = await import('../cliAgentDetectors');
+        const status = await codexDetector.detect();
+
+        expect(status.available).toBe(true);
+        expect(status.path).toBe('/Applications/Codex.app/Contents/Resources/codex');
+        expect(status.version).toBe('codex-cli 0.138.0-alpha.7');
+
+        // The validation call must target the bundled binary directly via execFile.
+        expect(execMock).not.toHaveBeenCalled();
+        const validateCall = execFileMock.mock.calls.at(-1)!;
+        expect(validateCall[0]).toBe('/Applications/Codex.app/Contents/Resources/codex');
+        expect(validateCall[1]).toEqual(['--version']);
+      } finally {
+        process.env.SHELL = originalShell;
+        process.env.PATH = originalPath;
+      }
+    });
+
     it('falls back to the login shell PATH for tools installed by shell setup', async () => {
       const originalPath = process.env.PATH;
       const originalShell = process.env.SHELL;

apps/desktop/src/main/modules/toolDetectors/cliAgentDetectors.ts

@@ -1,5 +1,5 @@
 import { exec, execFile } from 'node:child_process';
-import { platform } from 'node:os';
+import { homedir, platform } from 'node:os';
 import path from 'node:path';
 import { promisify } from 'node:util';
 
@@ -258,12 +258,34 @@ export const claudeCodeDetector: IToolDetector = createValidatedDetector({
   validateKeywords: ['claude code'],
 });
 
+/**
+ * OpenAI's Codex desktop app bundles the real `codex` CLI inside its `.app`
+ * but does not symlink it onto PATH. A user who installed only the desktop app
+ * would therefore fail PATH-based detection, so we probe the bundled binary as
+ * a fallback (tried after the PATH lookup, so a user's own install still wins).
+ * Both the system (`/Applications`) and per-user (`~/Applications`) install
+ * locations are covered. macOS only for now.
+ */
+const getCodexCandidates = (): string[] => {
+  const candidates = ['codex'];
+
+  if (platform() === 'darwin') {
+    const bundleRelativePath = 'Codex.app/Contents/Resources/codex';
+    candidates.push(
+      path.join('/Applications', bundleRelativePath),
+      path.join(homedir(), 'Applications', bundleRelativePath),
+    );
+  }
+
+  return candidates;
+};
+
 /**
  * OpenAI Codex CLI
  * @see https://github.com/openai/codex
  */
 export const codexDetector: IToolDetector = createValidatedDetector({
-  candidates: ['codex'],
+  candidates: getCodexCandidates(),
   description: 'Codex - OpenAI agentic coding CLI',
   name: 'codex',
   priority: 2,