Sip Voice Call Control

SIP Voice Call Control

Voice interface for OpenClaw using Telnyx Call Control API. Call via SIP and have natural conversations with your AI assistant.

How It Works

Your Phone (SIP) → Telnyx Call Control → Webhooks → This Server → Commands back
                         ↓                              ↓
                    STT/TTS/Media              LLM + Tool Execution

This is not WebRTC — it's server-side SIP call handling. Telnyx handles all audio; we just receive webhooks and send commands.

Setup

1. Install Dependencies

cd skills/sip-voice-call-control
npm install

2. Configure

cp .env.example .env

Edit .env:

TELNYX_API_KEY=KEY_your_api_key_here

3. Start Server

npm run start

Console shows:

🎙️  Assistant Voice Server ready on port 3000
📞 Dial: sip:openclaw@yourconnection.sip.telnyx.com

Agent Setup Flow

When setting up for a user, agents should:

1. Collect Configuration

Ask for:

1. Telnyx API Key (required) - Get from: https://portal.telnyx.com/#/app/auth/v2 - Needs Voice API + Inference permissions

2. TTS Voice (optional) - Telnyx.NaturalHD.astra — Female, warm and clear (default, recommended) - Telnyx.NaturalHD.atlas — Male, deep and authoritative - Polly.Amy-Neural — British female - Polly.Brian-Neural — British male - Polly.Joanna-Neural — American female - Polly.Matthew-Neural — American male - Azure.en-US-JennyNeural — American female - Azure.en-GB-RyanNeural — British male - See .env.example for full list

3. Voice Model (optional) - Qwen/Qwen3-235B-A22B — Best for function calling (default) - meta-llama/Meta-Llama-3.1-8B-Instruct — Fastest - meta-llama/Llama-3.3-70B-Instruct — Balanced

Personalization (assistant name, user name, timezone) is pulled automatically from workspace files (IDENTITY.md, USER.md).

2. Write .env File

cat > .env << 'EOF'
TELNYX_API_KEY=
VOICE_MODEL=Qwen/Qwen3-235B-A22B
TTS_VOICE=Telnyx.NaturalHD.astra
EOF

3. Start in Background (Persistent)

The server must run persistently to receive calls. Use nohup to keep it alive:

cd /path/to/sip-voice-call-control
nohup npm run start > sip-voice-call-control.log 2>&1 &

Or from an agent:

// Use nohup to keep process alive after session ends
exec({ 
  command: "cd /path/to/sip-voice-call-control && nohup npm run start > sip-voice-call-control.log 2>&1 &",
  background: true 
})

Important: Without nohup, the process will die when the parent session ends. Always use nohup or a process manager for production.

To check if running:

ps aux | grep "tsx.*dev" | grep -v grep

To stop:

pkill -f "tsx.*dev.ts"

To view logs:

tail -f /path/to/sip-voice-call-control/sip-voice-call-control.log

4. Extract SIP Address

Poll the process logs and give the user the SIP dial-in:

📞 Dial: sip:openclaw@.sip.telnyx.com

Environment Variables

| Variable | Required | Default | Description | |----------|----------|---------|-------------| | TELNYX_API_KEY | Yes | — | Telnyx API key | | VOICE_MODEL | No | Qwen/Qwen3-235B-A22B | Model for inference | | TTS_VOICE | No | Polly.Amy-Neural | Text-to-speech voice | | PORT | No | 3000 | Server port | | ENABLE_TUNNEL | No | true | Create Cloudflare tunnel | | WORKSPACE_DIR | No | ~/clawd | For memory search tool |

Available Tools

| Tool | Trigger Phrases | What It Does | |------|-----------------|--------------| | list_cron_jobs | "what reminders", "my schedule", "cron jobs" | Lists scheduled tasks | | add_reminder | "remind me", "set a reminder" | Creates new reminder | | remove_cron_job | "delete", "cancel" + job name | Removes a scheduled task | | get_weather | "weather", "temperature", "forecast" | Gets current weather | | search_memory | "what have we been working on", "projects" | Searches workspace files |

Features

Troubleshooting

No response after speaking:

Slow responses (>3s):

Tool not executing:

Port already in use:

Resources

1. Install Dependencies

cd skills/sip-voice-call-control
npm install

2. Configure

cp .env.example .env

Edit .env:

TELNYX_API_KEY=KEY_your_api_key_here

3. Start Server

npm run start

Console shows:

🎙️  Assistant Voice Server ready on port 3000
📞 Dial: sip:openclaw@yourconnection.sip.telnyx.com

No response after speaking:

Slow responses (>3s):

Tool not executing:

Port already in use: