voiceclaw
// Local voice I/O for OpenClaw agents. Transcribe inbound audio/voice messages using local Whisper (whisper.cpp) and generate voice replies using local Piper TTS. Requires whisper, piper, and ffmpeg pre-installed on the system. All inference runs on-device — no network calls, no cloud APIs, no API key
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updated:March 4, 2026
SKILL.mdreadonly
SKILL.md Frontmatter
namevoiceclaw
descriptionLocal voice I/O for OpenClaw agents. Transcribe inbound audio/voice messages using local Whisper (whisper.cpp) and generate voice replies using local Piper TTS. Requires whisper, piper, and ffmpeg pre-installed on the system. All inference runs on-device — no network calls, no cloud APIs, no API keys. Use when an agent receives a voice/audio message and should respond in both voice and text, or when any text response should be synthesized and sent as audio. Triggers on: voice messages, audio attachments, respond in voice, send as audio, speak this, voiceclaw.
metadata[object Object]
VoiceClaw
Local-only voice I/O for OpenClaw agents.
- STT:
transcribe.sh— converts audio to text via local Whisper binary - TTS:
speak.sh— converts text to speech via local Piper binary - Network calls: none — both scripts run fully offline
- No cloud APIs, no API keys required
Prerequisites
The following must be installed on the system before using this skill:
| Requirement | Purpose |
|---|---|
whisper binary | Speech-to-text inference |
ggml-base.en.bin model file | Whisper STT model |
piper binary | Text-to-speech synthesis |
*.onnx voice model files | Piper TTS voices |
ffmpeg | Audio format conversion |
See README.md for installation and setup instructions.
Environment Variables
| Variable | Default | Purpose |
|---|---|---|
WHISPER_BIN | auto-detected via which | Path to whisper binary |
WHISPER_MODEL | ~/.cache/whisper/ggml-base.en.bin | Path to Whisper model file |
PIPER_BIN | auto-detected via which | Path to piper binary |
VOICECLAW_VOICES_DIR | ~/.local/share/piper/voices | Directory containing .onnx voice model files |
Verify Setup
which whisper && echo "STT binary: OK"
which piper && echo "TTS binary: OK"
which ffmpeg && echo "ffmpeg: OK"
ls "${WHISPER_MODEL:-$HOME/.cache/whisper/ggml-base.en.bin}" && echo "STT model: OK"
ls "${VOICECLAW_VOICES_DIR:-$HOME/.local/share/piper/voices}"/*.onnx 2>/dev/null | head -1 && echo "TTS voices: OK"
Inbound Voice: Transcribe
# Transcribe audio → text (supports ogg, mp3, m4a, wav, flac)
TRANSCRIPT=$(bash scripts/transcribe.sh /path/to/audio.ogg)
Override model path:
WHISPER_MODEL=/path/to/ggml-base.en.bin bash scripts/transcribe.sh audio.ogg
Outbound Voice: Speak
# Step 1: Generate WAV (local Piper — no network)
WAV=$(bash scripts/speak.sh "Your response here." /tmp/reply.wav en_US-lessac-medium)
# Step 2: Convert to OGG Opus (Telegram voice requirement)
ffmpeg -i "$WAV" -c:a libopus -b:a 32k /tmp/reply.ogg -y -loglevel error
# Step 3: Send via message tool (filePath=/tmp/reply.ogg)
Override voice directory:
VOICECLAW_VOICES_DIR=/path/to/voices bash scripts/speak.sh "Hello." /tmp/reply.wav
Available Voices
| Voice | Style |
|---|---|
en_US-lessac-medium | Neutral American (default) |
en_US-amy-medium | Warm American female |
en_US-joe-medium | American male |
en_US-kusal-medium | Expressive American male |
en_US-danny-low | Deep American male (fast) |
en_GB-alba-medium | British female |
en_GB-northern_english_male-medium | Northern British male |
Agent Behavior Rules
- Voice in → Voice + Text out. Always respond with both a voice reply and a text reply when a voice message is received.
- Include the transcript. Show "🎙️ I heard: [transcript]" at the top of every text reply to a voice message.
- Keep voice responses concise. Piper TTS works best under ~200 words — summarize for audio, include full detail in text.
- Local only. Never use a cloud TTS/STT API. Only the local
whisperandpiperbinaries. - Send voice before text. Send the audio file first, then follow with the text reply.
Full Example
# 1. Transcribe inbound voice message
TRANSCRIPT=$(bash path/to/voiceclaw/scripts/transcribe.sh /path/to/voice.ogg)
# 2. Compose reply and generate audio
RESPONSE="Deployment complete. All checks passed."
WAV=$(bash path/to/voiceclaw/scripts/speak.sh "$RESPONSE" /tmp/reply_$$.wav)
ffmpeg -i "$WAV" -c:a libopus -b:a 32k /tmp/reply_$$.ogg -y -loglevel error
# 3. Send voice + text
# message(action=send, filePath=/tmp/reply_$$.ogg, ...)
# reply: "🎙️ I heard: $TRANSCRIPT\n\n$RESPONSE"
Troubleshooting
| Issue | Fix |
|---|---|
whisper: command not found | Ensure whisper binary is installed and in PATH |
| Whisper model not found | Set WHISPER_MODEL=/path/to/ggml-base.en.bin |
piper: command not found | Ensure piper binary is installed and in PATH |
| Voice model missing | Set VOICECLAW_VOICES_DIR=/path/to/voices/ |
| OGG won't play on Telegram | Ensure -c:a libopus flag in ffmpeg command |