---
phase: 25-file-system
plan: 08
subsystem: ui
tags: [voice, whisper, mediarecorder, transcription, react, express, multer]

# Dependency graph
requires:
  - phase: 25-file-system-02
    provides: ChatInput with file upload props, chat-files route with multer pattern
provides:
  - VoiceRecordButton component with MediaRecorder API, idle/recording/transcribing states
  - POST /transcribe server endpoint using execFileAsync for whisper-cpp or openai-whisper
  - ChatInput enableVoiceInput prop that renders VoiceRecordButton conditionally
affects: [25-file-system, chat-input, chat-panel]

# Tech tracking
tech-stack:
  added: []
  patterns:
    - "MediaRecorder API with 250ms chunk collection and onstop blob assembly"
    - "execFileAsync (not exec) for shell commands to avoid injection risk"
    - "Whisper CLI cascade: whisper-cpp first, openai-whisper Python fallback, 503 if neither"

key-files:
  created:
    - ui/src/components/VoiceRecordButton.tsx
  modified:
    - ui/src/components/ChatInput.tsx
    - ui/src/components/ChatPanel.tsx
    - server/src/routes/chat-files.ts
    - .planning/REQUIREMENTS.md

key-decisions:
  - "Use setValue state updater (functional form) for transcription append — avoids stale closure vs native DOM event approach"
  - "enableVoiceInput defaults to false for backward-compat; ChatPanel passes true unconditionally — server returns 503 gracefully if whisper absent"
  - "execFileAsync over exec for whisper CLI invocation — no shell injection risk with system-generated tmpPath"

patterns-established:
  - "POST /transcribe uses separate multer instance with field name 'audio' to avoid conflict with 'file' field used by upload routes"

requirements-completed: [INPUT-02, INPUT-03, INPUT-04]

# Metrics
duration: 8min
completed: 2026-04-01
---

# Phase 25 Plan 08: Voice Input Summary

**VoiceRecordButton with MediaRecorder API wired into ChatInput; POST /transcribe endpoint with whisper-cpp/openai-whisper cascade and graceful 503 fallback**

## Performance

- **Duration:** ~8 min
- **Started:** 2026-04-01T23:58:00Z
- **Completed:** 2026-04-01T23:59:00Z
- **Tasks:** 2
- **Files modified:** 5

## Accomplishments
- VoiceRecordButton component: idle (Mic), recording (Square/red), transcribing (Loader2 spinner) states using MediaRecorder API with 250ms chunks
- POST /transcribe endpoint: writes audio to temp file, tries whisper-cpp CLI first, falls back to openai-whisper Python CLI, returns 503 with helpful install message if neither is present
- ChatInput: new `enableVoiceInput` prop renders VoiceRecordButton; handleTranscription appends text to existing textarea value via functional setState
- ChatPanel passes `enableVoiceInput={true}` unconditionally (server returns 503 if whisper unavailable)
- INPUT-02, INPUT-03, INPUT-04 marked Complete in REQUIREMENTS.md

## Task Commits

Each task was committed atomically:

1. **Task 1: Create VoiceRecordButton and server transcription endpoint** - `c7c46a02` (feat)
2. **Task 2: Wire VoiceRecordButton into ChatInput and update REQUIREMENTS.md** - `a1e1b11b` (feat)

## Files Created/Modified
- `ui/src/components/VoiceRecordButton.tsx` - New voice recording button component with MediaRecorder API
- `ui/src/components/ChatInput.tsx` - Added enableVoiceInput prop, handleTranscription callback, VoiceRecordButton render
- `ui/src/components/ChatPanel.tsx` - Passes enableVoiceInput={true} to ChatInput
- `server/src/routes/chat-files.ts` - Added POST /transcribe endpoint with whisper CLI cascade
- `.planning/REQUIREMENTS.md` - Marked INPUT-02, INPUT-03, INPUT-04 as Complete

## Decisions Made
- Used functional form of setValue (`setValue((current) => ...)`) for transcription append to avoid stale closure issues — simpler than the native DOM event approach suggested in the plan
- enableVoiceInput defaults to false in ChatInput props for backward compatibility; ChatPanel passes true unconditionally since the server returns a friendly 503 if whisper is not installed
- Used a separate `audioUpload` multer instance with `.single("audio")` inside the transcribe handler to avoid field name collision with the existing `fileUpload` instance that uses `.single("file")`

## Deviations from Plan

### Auto-fixed Issues

**1. [Rule 1 - Bug] Added `path` import at top of chat-files.ts**
- **Found during:** Task 1 (server transcription endpoint)
- **Issue:** The plan's code used `path.join(tmpdir(), ...)` but `path` was not imported in the file
- **Fix:** Added `import path from "node:path";` at the top of chat-files.ts
- **Files modified:** server/src/routes/chat-files.ts
- **Verification:** TypeScript compiles without errors
- **Committed in:** c7c46a02 (Task 1 commit)

**2. [Rule 2 - Missing Critical] Separate multer instance for audio upload**
- **Found during:** Task 1 (server transcription endpoint)
- **Issue:** The plan's code called `runSingleFileUpload(fileUpload, req, res)` which uses `.single("file")` — but the audio field is named "audio", so no file would be found
- **Fix:** Created separate `audioUpload` multer instance and `runAudioUpload` helper using `.single("audio")`
- **Files modified:** server/src/routes/chat-files.ts
- **Verification:** TypeScript compiles without errors; logic matches field name used by VoiceRecordButton
- **Committed in:** c7c46a02 (Task 1 commit)

**3. [Rule 1 - Bug] Functional setState for transcription append**
- **Found during:** Task 2 (ChatInput integration)
- **Issue:** Plan suggested using native DOM event dispatch to update the textarea — unnecessarily complex since ChatInput uses controlled `value` state directly
- **Fix:** Used `setValue((current) => current ? \`\${current} \${text}\` : text)` which correctly appends without stale closure risk
- **Files modified:** ui/src/components/ChatInput.tsx
- **Verification:** TypeScript compiles without errors
- **Committed in:** a1e1b11b (Task 2 commit)

---

**Total deviations:** 3 auto-fixed (1 missing import, 1 field name mismatch, 1 simpler state approach)
**Impact on plan:** All fixes necessary for correctness. The path import and multer field name fixes would have caused runtime errors. The setState approach is simpler and more idiomatic React.

## Issues Encountered
None beyond the auto-fixed deviations above.

## User Setup Required
None — server returns 503 with install instructions if whisper is not present. No configuration required by default.

## Next Phase Readiness
- Voice input complete; INPUT-02/03/04 all marked Complete
- Remaining Phase 25 plans can proceed independently
- To enable transcription: install `whisper-cpp` (brew install whisper-cpp) or `openai-whisper` (pip install openai-whisper)

---
*Phase: 25-file-system*
*Completed: 2026-04-01*
