OpenClaw Voice

Open-source browser-based voice interface for AI assistants.

Talk to your AI like you talk to Alexa — but self-hosted, private, and connected to your own agent.

🌐 Website: openclawvoice.com

Features

Feature	Description
🎤 Local STT	Whisper runs locally via faster-whisper. Your voice never leaves your machine.
🔊 Streaming TTS	ElevenLabs with sentence-by-sentence streaming. Hear responses while they generate.
🎯 Voice Activity Detection	Silero VAD filters background noise. Works in noisy environments.
🧹 Smart Text Cleaning	Strips markdown, hashtags, URLs before TTS. No more "hash hash".
🔌 Any AI Backend	OpenAI, Claude, or full OpenClaw agent with memory and tools.
🌐 Browser-Based	No app install. Works on desktop and mobile.
🚗 Continuous Mode	Hands-free conversation. Auto-listens after each response.

Quick Start

# Clone
git clone https://github.com/Purple-Horizons/openclaw-voice.git
cd openclaw-voice

# Install
python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt

# Optional: Install VAD support (better noise handling)
pip install torch torchaudio

# Configure (create .env from example)
cp .env.example .env
# Edit .env with your API keys

# Run
PYTHONPATH=. python -m src.server.main

# Open http://localhost:8765

For OpenClaw Agents (Auto-Install)

One-liner for AI agents to self-install:

cd /tmp && \
git clone https://github.com/Purple-Horizons/openclaw-voice.git && \
cd openclaw-voice && \
python3 -m venv .venv && source .venv/bin/activate && \
pip install -r requirements.txt torch torchaudio && \
PYTHONPATH=. ELEVENLABS_API_KEY="$ELEVENLABS_API_KEY" OPENAI_API_KEY="$OPENAI_API_KEY" \
  nohup python -m src.server.main > /tmp/voice-server.log 2>&1 &

Configuration

Environment Variables

Variable	Required	Default	Description
ELEVENLABS_API_KEY	Yes*	—	ElevenLabs API key for TTS
OPENAI_API_KEY	Yes*	—	OpenAI API key (if not using gateway)
OPENCLAW_GATEWAY_URL	No	—	OpenClaw gateway URL for full agent
OPENCLAW_GATEWAY_TOKEN	No	—	Gateway auth token
OPENCLAW_PORT	No	8765	Server port
OPENCLAW_STT_MODEL	No	base	Whisper model size
OPENCLAW_STT_DEVICE	No	auto	Device: auto, cpu, cuda, mps
OPENCLAW_REQUIRE_AUTH	No	false	Require API keys for clients

*One of OPENAI_API_KEY or OPENCLAW_GATEWAY_URL required.

Whisper Model Sizes

Model	Speed	Quality	VRAM	Best For
tiny	Fastest	Fair	~400MB	Quick testing
base	Fast	Good	~1GB	Default. Good balance.
small	Medium	Better	~2GB	Clearer transcription
medium	Slower	Great	~5GB	Accuracy priority
large-v3-turbo	Slow	Best	~6GB	Maximum accuracy

TTS Options

Backend	Type	Quality	Latency	Notes
ElevenLabs	Cloud	Excellent	~500ms	Default. Streaming supported.
Chatterbox	Local	Very Good	~1s	MIT license, voice cloning
XTTS-v2	Local	Excellent	~1s	Voice cloning supported
Mock	Local	None	0ms	For testing (silence)

ElevenLabs uses eleven_turbo_v2_5 for fastest response.

OpenClaw Gateway Integration

Connect to your full OpenClaw agent (same memory, tools, and persona as text chat):

# .env
OPENCLAW_GATEWAY_URL=http://localhost:18789
OPENCLAW_GATEWAY_TOKEN=your-token
ELEVENLABS_API_KEY=your-key

Add to your openclaw.json:

{
  "gateway": {
    "http": {
      "endpoints": {
        "chatCompletions": { "enabled": true }
      }
    }
  },
  "agents": {
    "list": [
      {
        "id": "voice",
        "workspace": "/path/to/workspace",
        "model": "anthropic/claude-sonnet-4-5"
      }
    ]
  }
}

Architecture

┌─────────────┐   WebSocket   ┌─────────────────────────────────────┐
│   Browser   │◄────────────►│          Voice Server               │
│  (mic/spk)  │               │                                     │
└─────────────┘               │  ┌─────────┐  ┌─────┐  ┌─────────┐ │
                              │  │ Whisper │→│ AI  │→│ElevenLabs│ │
                              │  │  (STT)  │  │     │  │  (TTS)  │ │
                              │  └─────────┘  └─────┘  └─────────┘ │
                              │       ↑                     │      │
                              │    [VAD]              [streaming]  │
                              └─────────────────────────────────────┘

Streaming Flow:

1. User speaks → Whisper transcribes locally
2. AI responds (streamed) → buffer sentences
3. First sentence complete → TTS starts immediately
4. Audio streams to browser while AI continues
5. Result: ~50% faster perceived response

HTTPS for Mobile

Mobile browsers require HTTPS for microphone access. Options:

Tailscale Funnel (easiest):

tailscale funnel 8765
# Access via https://your-machine.tailnet-name.ts.net

nginx + Let's Encrypt:

server {
    listen 443 ssl;
    server_name voice.yourdomain.com;
    
    location / {
        proxy_pass http://127.0.0.1:8765;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
    }
}

API

WebSocket Protocol

Connect to ws://localhost:8765/ws:

// Start recording
{ "type": "start_listening" }

// Send audio (base64 PCM float32, 16kHz)
{ "type": "audio", "data": "base64..." }

// Stop recording
{ "type": "stop_listening" }

// Receive events:
{ "type": "transcript", "text": "...", "final": true }
{ "type": "response_chunk", "text": "..." }        // Streaming text
{ "type": "audio_chunk", "data": "...", "sample_rate": 24000 }  // Streaming audio
{ "type": "response_complete", "text": "..." }     // Full response
{ "type": "vad_status", "speech_detected": true }  // VAD feedback

Roadmap

• WebSocket voice gateway
• Whisper STT (local)
• ElevenLabs TTS
• Streaming TTS (sentence-by-sentence)
• Voice Activity Detection (Silero)
• Text cleaning (markdown/hashtags/URLs)
• Continuous conversation mode
• OpenClaw gateway integration
• WebRTC for lower latency
• Voice cloning UI
• Docker support

License

MIT License — see LICENSE.

Credits

• faster-whisper — Local STT
• ElevenLabs — Text-to-Speech
• Silero VAD — Voice Activity Detection
• Built for OpenClaw

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Made with 🦞 by Purple Horizons