Add Voice Transcription

Add Voice Transcription

This skill adds automatic voice message transcription to MatClaw's WhatsApp channel using OpenAI's Whisper API. When a voice note arrives, it is downloaded, transcribed, and delivered to the agent as [Voice: <transcript>].

Phase 1: Pre-flight

Check if already applied

Read .matclaw/state.yaml. If voice-transcription is in applied_skills, skip to Phase 3 (Configure). The code changes are already in place.

Ask the user

Use AskUserQuestion to collect information:

AskUserQuestion: Do you have an OpenAI API key for Whisper transcription?

If yes, collect it now. If no, direct them to create one at https://platform.openai.com/api-keys.

Phase 2: Apply Code Changes

Run the skills engine to apply this skill's code package.

Initialize skills system (if needed)

If .matclaw/ directory doesn't exist yet:

npx tsx scripts/apply-skill.ts --init

Apply the skill

npx tsx scripts/apply-skill.ts .claude/skills/add-voice-transcription

This deterministically:

• Adds src/transcription.ts (voice transcription module using OpenAI Whisper)
• Three-way merges voice handling into src/channels/whatsapp.ts (isVoiceMessage check, transcribeAudioMessage call)
• Three-way merges transcription tests into src/channels/whatsapp.test.ts (mock + 3 test cases)
• Installs the openai npm dependency
• Updates .env.example with OPENAI_API_KEY
• Records the application in .matclaw/state.yaml

If the apply reports merge conflicts, read the intent files:

• modify/src/channels/whatsapp.ts.intent.md — what changed and invariants for whatsapp.ts
• modify/src/channels/whatsapp.test.ts.intent.md — what changed for whatsapp.test.ts

Validate code changes

npm test
npm run build

All tests must pass (including the 3 new voice transcription tests) and build must be clean before proceeding.

Phase 3: Configure

Get OpenAI API key (if needed)

If the user doesn't have an API key:

I need you to create an OpenAI API key:

1. Go to https://platform.openai.com/api-keys
2. Click "Create new secret key"
3. Give it a name (e.g., "MatClaw Transcription")
4. Copy the key (starts with sk-)

Cost: $0.006 per minute of audio ($0.003 per typical 30-second voice note)

Wait for the user to provide the key.

Add to environment

Add to .env:

OPENAI_API_KEY=<their-key>

Sync to container environment:

mkdir -p data/env && cp .env data/env/env

The container reads environment from data/env/env, not .env directly.

Build and restart

npm run build
launchctl kickstart -k gui/$(id -u)/com.matclaw  # macOS
# Linux: systemctl --user restart matclaw

Phase 4: Verify

Test with a voice note

Tell the user:

Send a voice note in any registered WhatsApp chat. The agent should receive it as [Voice: <transcript>] and respond to its content.

Check logs if needed

tail -f logs/matclaw.log | grep -i voice

Look for:

• Transcribed voice message — successful transcription with character count
• OPENAI_API_KEY not set — key missing from .env
• OpenAI transcription failed — API error (check key validity, billing)
• Failed to download audio message — media download issue

Troubleshooting

Voice notes show "[Voice Message - transcription unavailable]"

1. Check OPENAI_API_KEY is set in .env AND synced to data/env/env
2. Verify key works: curl -s https://api.openai.com/v1/models -H "Authorization: Bearer $OPENAI_API_KEY" | head -c 200
3. Check OpenAI billing — Whisper requires a funded account

Voice notes show "[Voice Message - transcription failed]"

Check logs for the specific error. Common causes:

• Network timeout — transient, will work on next message
• Invalid API key — regenerate at https://platform.openai.com/api-keys
• Rate limiting — wait and retry

Agent doesn't respond to voice notes

Verify the chat is registered and the agent is running. Voice transcription only runs for registered groups.