- name
- sip-voice-call-control
- description
- Voice interface using Telnyx Call Control API. Answer phone calls with AI, function calling, and natural conversation. Use for hands-free assistant access, phone-based reminders, or voice-controlled tools. Requires Node.js and Telnyx API key.
- metadata
- {"openclaw":{"emoji":"📞","requires":{"bins":["node","npm"],"env":["TELNYX_API_KEY"]},"primaryEnv":"TELNYX_API_KEY"}}
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 ExecutionThis 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 install2. Configure
cp .env.example .envEdit .env:
TELNYX_API_KEY=KEY_your_api_key_here3. Start Server
npm run startConsole shows:
🎙️ Assistant Voice Server ready on port 3000
📞 Dial: sip:openclaw@yourconnection.sip.telnyx.comAgent Setup Flow
When setting up for a user, agents should:
1. Collect Configuration
Ask for:
- Telnyx API Key (required)
- Get from: https://portal.telnyx.com/#/app/auth/v2 - Needs Voice API + Inference permissions
- 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
- 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=<user_api_key>
VOICE_MODEL=Qwen/Qwen3-235B-A22B
TTS_VOICE=Telnyx.NaturalHD.astra
EOF3. 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 grepTo stop:
pkill -f "tsx.*dev.ts"To view logs:
tail -f /path/to/sip-voice-call-control/sip-voice-call-control.log4. Extract SIP Address
Poll the process logs and give the user the SIP dial-in:
📞 Dial: sip:openclaw@<connection>.sip.telnyx.comEnvironment 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
- Low-latency — 500ms-1.5s response time with
enable_thinking: false - Barge-in — Interrupt the assistant anytime by speaking
- Function calling — Native tool support with Qwen
- Auto-setup — Cloudflare tunnel and Call Control app created automatically
- Personalization — Reads
IDENTITY.mdandUSER.mdfor context
Troubleshooting
No response after speaking:
- Check Telnyx API key has Voice API + Inference permissions
- Verify webhook URL is reachable (tunnel must be active)
Slow responses (>3s):
- Ensure using
function-callingbranch (notmain) - Check model availability on your Telnyx account
Tool not executing:
- Ensure
openclawCLI is in PATH - Check
WORKSPACE_DIRis set correctly
Port already in use:
- Kill existing server:
pkill -f "tsx.*dev.ts" - Or change
PORTin .env
Resources
- Telnyx Call Control: https://developers.telnyx.com/docs/voice/call-control
- Telnyx Inference: https://developers.telnyx.com/docs/inference
- See ARCHITECTURE.md for technical details