feat(worktree): add AI commit message generation feature

- Implemented a new endpoint to generate commit messages based on git diffs.
- Updated worktree routes to include the AI commit message generation functionality.
- Enhanced the UI to support automatic generation of commit messages when the commit dialog opens, based on user settings.
- Added settings for enabling/disabling AI-generated commit messages and configuring the model used for generation.

apps/server/src/index.ts

@@ -217,7 +217,7 @@ app.use('/api/sessions', createSessionsRoutes(agentService));
 app.use('/api/features', createFeaturesRoutes(featureLoader));
 app.use('/api/auto-mode', createAutoModeRoutes(autoModeService));
 app.use('/api/enhance-prompt', createEnhancePromptRoutes(settingsService));
-app.use('/api/worktree', createWorktreeRoutes(events));
+app.use('/api/worktree', createWorktreeRoutes(events, settingsService));
 app.use('/api/git', createGitRoutes());
 app.use('/api/suggestions', createSuggestionsRoutes(events, settingsService));
 app.use('/api/models', createModelsRoutes());

apps/server/src/routes/worktree/index.ts

@@ -40,8 +40,12 @@ import {
   createDeleteInitScriptHandler,
   createRunInitScriptHandler,
 } from './routes/init-script.js';
+import type { SettingsService } from '../../services/settings-service.js';
 
-export function createWorktreeRoutes(events: EventEmitter): Router {
+export function createWorktreeRoutes(
+  events: EventEmitter,
+  settingsService?: SettingsService
+): Router {
   const router = Router();
 
   router.post('/info', validatePathParams('projectPath'), createInfoHandler());
@@ -69,7 +73,7 @@ export function createWorktreeRoutes(events: EventEmitter): Router {
     '/generate-commit-message',
     validatePathParams('worktreePath'),
     requireGitRepoOnly,
-    createGenerateCommitMessageHandler()
+    createGenerateCommitMessageHandler(settingsService)
   );
   router.post(
     '/push',

apps/server/src/routes/worktree/routes/generate-commit-message.ts

@@ -1,7 +1,8 @@
 /**
  * POST /worktree/generate-commit-message endpoint - Generate an AI commit message from git diff
  *
- * Uses Claude Haiku to generate a concise, conventional commit message from git changes.
+ * Uses the configured model (via phaseModels.commitMessageModel) to generate a concise,
+ * conventional commit message from git changes. Defaults to Claude Haiku for speed.
  */
 
 import type { Request, Response } from 'express';
@@ -9,12 +10,26 @@ import { exec } from 'child_process';
 import { promisify } from 'util';
 import { query } from '@anthropic-ai/claude-agent-sdk';
 import { createLogger } from '@automaker/utils';
-import { CLAUDE_MODEL_MAP } from '@automaker/model-resolver';
+import { DEFAULT_PHASE_MODELS, isCursorModel, stripProviderPrefix } from '@automaker/types';
+import { resolvePhaseModel } from '@automaker/model-resolver';
+import { mergeCommitMessagePrompts } from '@automaker/prompts';
+import { ProviderFactory } from '../../../providers/provider-factory.js';
+import type { SettingsService } from '../../../services/settings-service.js';
 import { getErrorMessage, logError } from '../common.js';
 
 const logger = createLogger('GenerateCommitMessage');
 const execAsync = promisify(exec);
 
+/**
+ * Get the effective system prompt for commit message generation.
+ * Uses custom prompt from settings if enabled, otherwise falls back to default.
+ */
+async function getSystemPrompt(settingsService?: SettingsService): Promise<string> {
+  const settings = await settingsService?.getGlobalSettings();
+  const prompts = mergeCommitMessagePrompts(settings?.promptCustomization?.commitMessage);
+  return prompts.systemPrompt;
+}
+
 interface GenerateCommitMessageRequestBody {
   worktreePath: string;
 }
@@ -29,23 +44,6 @@ interface GenerateCommitMessageErrorResponse {
   error: string;
 }
 
-const SYSTEM_PROMPT = `You are a git commit message generator. Your task is to create a clear, concise commit message based on the git diff provided.
-
-Rules:
-- Output ONLY the commit message, nothing else
-- First line should be a short summary (50 chars or less) in imperative mood
-- Start with a conventional commit type if appropriate (feat:, fix:, refactor:, docs:, etc.)
-- Keep it concise and descriptive
-- Focus on WHAT changed and WHY (if clear from the diff), not HOW
-- No quotes, backticks, or extra formatting
-- If there are multiple changes, provide a brief summary on the first line
-
-Examples:
-- feat: Add dark mode toggle to settings
-- fix: Resolve login validation edge case
-- refactor: Extract user authentication logic
-- docs: Update installation instructions`;
-
 async function extractTextFromStream(
   stream: AsyncIterable<{
     type: string;
@@ -73,10 +71,9 @@ async function extractTextFromStream(
   return responseText;
 }
 
-export function createGenerateCommitMessageHandler(): (
-  req: Request,
-  res: Response
-) => Promise<void> {
+export function createGenerateCommitMessageHandler(
+  settingsService?: SettingsService
+): (req: Request, res: Response) => Promise<void> {
   return async (req: Request, res: Response): Promise<void> => {
     try {
       const { worktreePath } = req.body as GenerateCommitMessageRequestBody;
@@ -136,21 +133,66 @@ export function createGenerateCommitMessageHandler(): (
 
       const userPrompt = `Generate a commit message for these changes:\n\n\`\`\`diff\n${truncatedDiff}\n\`\`\``;
 
-      const stream = query({
-        prompt: userPrompt,
-        options: {
-          model: CLAUDE_MODEL_MAP.haiku,
-          systemPrompt: SYSTEM_PROMPT,
+      // Get model from phase settings
+      const settings = await settingsService?.getGlobalSettings();
+      const phaseModelEntry =
+        settings?.phaseModels?.commitMessageModel || DEFAULT_PHASE_MODELS.commitMessageModel;
+      const { model } = resolvePhaseModel(phaseModelEntry);
+
+      logger.info(`Using model for commit message: ${model}`);
+
+      // Get the effective system prompt (custom or default)
+      const systemPrompt = await getSystemPrompt(settingsService);
+
+      let message: string;
+
+      // Route to appropriate provider based on model type
+      if (isCursorModel(model)) {
+        // Use Cursor provider for Cursor models
+        logger.info(`Using Cursor provider for model: ${model}`);
+
+        const provider = ProviderFactory.getProviderForModel(model);
+        const bareModel = stripProviderPrefix(model);
+
+        const cursorPrompt = `${systemPrompt}\n\n${userPrompt}`;
+
+        let responseText = '';
+        for await (const msg of provider.executeQuery({
+          prompt: cursorPrompt,
+          model: bareModel,
+          cwd: worktreePath,
           maxTurns: 1,
           allowedTools: [],
-          permissionMode: 'default',
-        },
-      });
+          readOnly: true,
+        })) {
+          if (msg.type === 'assistant' && msg.message?.content) {
+            for (const block of msg.message.content) {
+              if (block.type === 'text' && block.text) {
+                responseText += block.text;
+              }
+            }
+          }
+        }
 
-      const message = await extractTextFromStream(stream);
+        message = responseText.trim();
+      } else {
+        // Use Claude SDK for Claude models
+        const stream = query({
+          prompt: userPrompt,
+          options: {
+            model,
+            systemPrompt,
+            maxTurns: 1,
+            allowedTools: [],
+            permissionMode: 'default',
+          },
+        });
+
+        message = await extractTextFromStream(stream);
+      }
 
       if (!message || message.trim().length === 0) {
-        logger.warn('Received empty response from Claude');
+        logger.warn('Received empty response from model');
         const response: GenerateCommitMessageErrorResponse = {
           success: false,
           error: 'Failed to generate commit message - empty response',

apps/ui/src/components/views/board-view/dialogs/commit-worktree-dialog.tsx

@@ -13,6 +13,7 @@ import { Label } from '@/components/ui/label';
 import { GitCommit, Loader2, Sparkles } from 'lucide-react';
 import { getElectronAPI } from '@/lib/electron';
 import { toast } from 'sonner';
+import { useAppStore } from '@/store/app-store';
 
 interface WorktreeInfo {
   path: string;
@@ -39,6 +40,7 @@ export function CommitWorktreeDialog({
   const [isLoading, setIsLoading] = useState(false);
   const [isGenerating, setIsGenerating] = useState(false);
   const [error, setError] = useState<string | null>(null);
+  const enableAiCommitMessages = useAppStore((state) => state.enableAiCommitMessages);
 
   const handleCommit = async () => {
     if (!worktree || !message.trim()) return;
@@ -83,19 +85,24 @@ export function CommitWorktreeDialog({
     }
   };
 
-  // Generate AI commit message when dialog opens
+  // Generate AI commit message when dialog opens (if enabled)
   useEffect(() => {
     if (open && worktree) {
       // Reset state
       setMessage('');
       setError(null);
+
+      // Only generate AI commit message if enabled
+      if (!enableAiCommitMessages) {
+        return;
+      }
+
       setIsGenerating(true);
 
       const generateMessage = async () => {
         try {
           const api = getElectronAPI();
           if (!api?.worktree?.generateCommitMessage) {
-            setError('AI commit message generation not available');
             setIsGenerating(false);
             return;
           }
@@ -120,7 +127,7 @@ export function CommitWorktreeDialog({
 
       generateMessage();
     }
-  }, [open, worktree]);
+  }, [open, worktree, enableAiCommitMessages]);
 
   if (!worktree) return null;
 

apps/ui/src/components/views/settings-view.tsx

@@ -44,6 +44,8 @@ export function SettingsView() {
     setEnableDependencyBlocking,
     skipVerificationInAutoMode,
     setSkipVerificationInAutoMode,
+    enableAiCommitMessages,
+    setEnableAiCommitMessages,
     useWorktrees,
     setUseWorktrees,
     muteDoneSound,
@@ -182,11 +184,13 @@ export function SettingsView() {
             skipVerificationInAutoMode={skipVerificationInAutoMode}
             defaultPlanningMode={defaultPlanningMode}
             defaultRequirePlanApproval={defaultRequirePlanApproval}
+            enableAiCommitMessages={enableAiCommitMessages}
             onDefaultSkipTestsChange={setDefaultSkipTests}
             onEnableDependencyBlockingChange={setEnableDependencyBlocking}
             onSkipVerificationInAutoModeChange={setSkipVerificationInAutoMode}
             onDefaultPlanningModeChange={setDefaultPlanningMode}
             onDefaultRequirePlanApprovalChange={setDefaultRequirePlanApproval}
+            onEnableAiCommitMessagesChange={setEnableAiCommitMessages}
           />
         );
       case 'worktrees':

apps/ui/src/components/views/settings-view/feature-defaults/feature-defaults-section.tsx

@@ -10,6 +10,7 @@ import {
   ScrollText,
   ShieldCheck,
   FastForward,
+  Sparkles,
 } from 'lucide-react';
 import { cn } from '@/lib/utils';
 import {
@@ -28,11 +29,13 @@ interface FeatureDefaultsSectionProps {
   skipVerificationInAutoMode: boolean;
   defaultPlanningMode: PlanningMode;
   defaultRequirePlanApproval: boolean;
+  enableAiCommitMessages: boolean;
   onDefaultSkipTestsChange: (value: boolean) => void;
   onEnableDependencyBlockingChange: (value: boolean) => void;
   onSkipVerificationInAutoModeChange: (value: boolean) => void;
   onDefaultPlanningModeChange: (value: PlanningMode) => void;
   onDefaultRequirePlanApprovalChange: (value: boolean) => void;
+  onEnableAiCommitMessagesChange: (value: boolean) => void;
 }
 
 export function FeatureDefaultsSection({
@@ -41,11 +44,13 @@ export function FeatureDefaultsSection({
   skipVerificationInAutoMode,
   defaultPlanningMode,
   defaultRequirePlanApproval,
+  enableAiCommitMessages,
   onDefaultSkipTestsChange,
   onEnableDependencyBlockingChange,
   onSkipVerificationInAutoModeChange,
   onDefaultPlanningModeChange,
   onDefaultRequirePlanApprovalChange,
+  onEnableAiCommitMessagesChange,
 }: FeatureDefaultsSectionProps) {
   return (
     <div
@@ -251,6 +256,34 @@ export function FeatureDefaultsSection({
             </p>
           </div>
         </div>
+
+        {/* Separator */}
+        <div className="border-t border-border/30" />
+
+        {/* AI Commit Messages Setting */}
+        <div className="group flex items-start space-x-3 p-3 rounded-xl hover:bg-accent/30 transition-colors duration-200 -mx-3">
+          <Checkbox
+            id="enable-ai-commit-messages"
+            checked={enableAiCommitMessages}
+            onCheckedChange={(checked) => onEnableAiCommitMessagesChange(checked === true)}
+            className="mt-1"
+            data-testid="enable-ai-commit-messages-checkbox"
+          />
+          <div className="space-y-1.5">
+            <Label
+              htmlFor="enable-ai-commit-messages"
+              className="text-foreground cursor-pointer font-medium flex items-center gap-2"
+            >
+              <Sparkles className="w-4 h-4 text-brand-500" />
+              Generate AI commit messages
+            </Label>
+            <p className="text-xs text-muted-foreground/80 leading-relaxed">
+              When enabled, opening the commit dialog will automatically generate a commit message
+              using AI based on your staged or unstaged changes. You can configure the model used in
+              Model Defaults.
+            </p>
+          </div>
+        </div>
       </div>
     </div>
   );

apps/ui/src/components/views/settings-view/model-defaults/model-defaults-section.tsx

@@ -28,6 +28,11 @@ const QUICK_TASKS: PhaseConfig[] = [
     label: 'Image Descriptions',
     description: 'Analyzes and describes context images',
   },
+  {
+    key: 'commitMessageModel',
+    label: 'Commit Messages',
+    description: 'Generates git commit messages from diffs',
+  },
 ];
 
 const VALIDATION_TASKS: PhaseConfig[] = [

apps/ui/src/lib/electron.ts

@@ -1538,11 +1538,10 @@ function createMockWorktreeAPI(): WorktreeAPI {
     },
 
     generateCommitMessage: async (worktreePath: string) => {
-      console.log('[Mock] Generating commit message:', { worktreePath });
+      console.log('[Mock] Generating commit message for:', worktreePath);
       return {
         success: true,
-        message:
-          'feat: Add new feature implementation\n\nThis is a mock AI-generated commit message.',
+        message: 'feat: Add mock commit message generation',
       };
     },
 

apps/ui/src/store/app-store.ts

@@ -536,6 +536,7 @@ export interface AppState {
   defaultSkipTests: boolean; // Default value for skip tests when creating new features
   enableDependencyBlocking: boolean; // When true, show blocked badges and warnings for features with incomplete dependencies (default: true)
   skipVerificationInAutoMode: boolean; // When true, auto-mode grabs features even if dependencies are not verified (only checks they're not running)
+  enableAiCommitMessages: boolean; // When true, auto-generate commit messages using AI when opening commit dialog
   planUseSelectedWorktreeBranch: boolean; // When true, Plan dialog creates features on the currently selected worktree branch
   addFeatureUseSelectedWorktreeBranch: boolean; // When true, Add Feature dialog defaults to custom mode with selected worktree branch
 
@@ -932,6 +933,7 @@ export interface AppActions {
   setDefaultSkipTests: (skip: boolean) => void;
   setEnableDependencyBlocking: (enabled: boolean) => void;
   setSkipVerificationInAutoMode: (enabled: boolean) => Promise<void>;
+  setEnableAiCommitMessages: (enabled: boolean) => Promise<void>;
   setPlanUseSelectedWorktreeBranch: (enabled: boolean) => Promise<void>;
   setAddFeatureUseSelectedWorktreeBranch: (enabled: boolean) => Promise<void>;
 
@@ -1218,6 +1220,7 @@ const initialState: AppState = {
   defaultSkipTests: true, // Default to manual verification (tests disabled)
   enableDependencyBlocking: true, // Default to enabled (show dependency blocking UI)
   skipVerificationInAutoMode: false, // Default to disabled (require dependencies to be verified)
+  enableAiCommitMessages: true, // Default to enabled (auto-generate commit messages)
   planUseSelectedWorktreeBranch: true, // Default to enabled (Plan creates features on selected worktree branch)
   addFeatureUseSelectedWorktreeBranch: false, // Default to disabled (Add Feature uses normal defaults)
   useWorktrees: true, // Default to enabled (git worktree isolation)
@@ -1848,6 +1851,17 @@ export const useAppStore = create<AppState & AppActions>()((set, get) => ({
     const { syncSettingsToServer } = await import('@/hooks/use-settings-migration');
     await syncSettingsToServer();
   },
+  setEnableAiCommitMessages: async (enabled) => {
+    const previous = get().enableAiCommitMessages;
+    set({ enableAiCommitMessages: enabled });
+    // Sync to server settings file
+    const { syncSettingsToServer } = await import('@/hooks/use-settings-migration');
+    const ok = await syncSettingsToServer();
+    if (!ok) {
+      logger.error('Failed to sync enableAiCommitMessages setting to server - reverting');
+      set({ enableAiCommitMessages: previous });
+    }
+  },
   setPlanUseSelectedWorktreeBranch: async (enabled) => {
     const previous = get().planUseSelectedWorktreeBranch;
     set({ planUseSelectedWorktreeBranch: enabled });

libs/types/src/settings.ts

@@ -157,6 +157,10 @@ export interface PhaseModelConfig {
   // Memory tasks - for learning extraction and memory operations
   /** Model for extracting learnings from completed agent sessions */
   memoryExtractionModel: PhaseModelEntry;
+
+  // Quick tasks - commit messages
+  /** Model for generating git commit messages from diffs */
+  commitMessageModel: PhaseModelEntry;
 }
 
 /** Keys of PhaseModelConfig for type-safe access */
@@ -398,6 +402,10 @@ export interface GlobalSettings {
   /** Priority for ntfy notifications (1-5, default: 3) */
   ntfyPriority: 1 | 2 | 3 | 4 | 5;
 
+  // AI Commit Message Generation
+  /** Enable AI-generated commit messages when opening commit dialog (default: true) */
+  enableAiCommitMessages: boolean;
+
   // AI Model Selection (per-phase configuration)
   /** Phase-specific AI model configuration */
   phaseModels: PhaseModelConfig;
@@ -669,6 +677,9 @@ export const DEFAULT_PHASE_MODELS: PhaseModelConfig = {
 
   // Memory - use fast model for learning extraction (cost-effective)
   memoryExtractionModel: { model: 'haiku' },
+
+  // Commit messages - use fast model for speed
+  commitMessageModel: { model: 'haiku' },
 };
 
 /** Current version of the global settings schema */
@@ -724,6 +735,7 @@ export const DEFAULT_GLOBAL_SETTINGS: GlobalSettings = {
   ntfyTopic: '',
   ntfyAuthToken: undefined,
   ntfyPriority: 3,
+  enableAiCommitMessages: true,
   phaseModels: DEFAULT_PHASE_MODELS,
   enhancementModel: 'sonnet',
   validationModel: 'opus',