Phone Voice Integration

---

name: phone-voice

description: Connect ElevenLabs Agents to your OpenClaw via phone with Twilio. Includes caller ID auth, voice PIN security, call screening, memory injection, and cost tracking.

version: 2.0.0

author: Fred (@FredMolty)

---

# Phone Voice Integration

Turn your OpenClaw into a phone-callable assistant with ElevenLabs Agents + Twilio.

**What you get:**

Architecture

Phone → Twilio → ElevenLabs Agent → Your Bridge → Anthropic Claude → OpenClaw Tools
                                          ↓
                                    Memory Context
                                    (MEMORY.md, USER.md)

**Flow:**

1. Caller dials your Twilio number

2. Twilio routes to ElevenLabs Agent

3. Agent sends chat completions to your bridge (mimics OpenAI API)

4. Bridge translates to Anthropic, injects context from memory files

5. Claude response → ElevenLabs TTS → caller hears it

Prerequisites

Setup

1. Enable Chat Completions in OpenClaw

Not needed for this skill — the bridge bypasses OpenClaw and calls Claude directly. This gives you more control over memory injection and cost tracking.

2. Create the Bridge Server

The bridge is a FastAPI server that:

**Key files:**

3. Set Up Cloudflare Tunnel (Recommended)

Permanent, secure alternative to ngrok:

# Install cloudflared
brew install cloudflare/cloudflare/cloudflared

# Login and configure
cloudflared tunnel login
cloudflared tunnel create <tunnel-name>

# Run the tunnel
cloudflared tunnel --url http://localhost:8013 run <tunnel-name>

Add a CNAME in Cloudflare DNS:

voice.yourdomain.com → <tunnel-id>.cfargotunnel.com

**Or use ngrok (temporary):**

ngrok http 8013

4. Configure ElevenLabs Agent

#### Option A: Manual (UI)

1. Go to ElevenLabs dashboard → Conversational AI

2. Create new agent

3. Under LLM settings → Custom LLM

4. Set URL: `https://voice.yourdomain.com/v1/chat/completions`

5. Add header: `Authorization: Bearer <YOUR_BRIDGE_TOKEN>`

#### Option B: Programmatic (API)

# Step 1: Store your bridge auth token as a secret
curl -X POST https://api.elevenlabs.io/v1/convai/secrets \
  -H "xi-api-key: YOUR_ELEVENLABS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "type": "new",
    "name": "bridge_auth_token",
    "value": "YOUR_BRIDGE_AUTH_TOKEN"
  }'

# Response: {"secret_id": "abc123..."}

# Step 2: Create the agent
curl -X POST https://api.elevenlabs.io/v1/convai/agents/create \
  -H "xi-api-key: YOUR_ELEVENLABS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "conversation_config": {
      "agent": {
        "language": "en",
        "prompt": {
          "llm": "custom-llm",
          "prompt": "You are a helpful voice assistant.",
          "custom_llm": {
            "url": "https://voice.yourdomain.com/v1/chat/completions",
            "api_key": {"secret_id": "abc123..."}
          }
        }
      }
    }
  }'

5. Connect Twilio Phone Number

In ElevenLabs agent settings:

1. Go to **Phone** section

2. Enter Twilio Account SID and Auth Token

3. Select your Twilio phone number

4. Save

Done! Your bot now answers that phone number.

Security Features

Caller ID Authentication

Recognizes whitelisted numbers automatically:

// contacts.json
{
  "+12505551234": {
    "name": "Alice",
    "role": "family"
  }
}

Voice PIN Challenge

For unknown callers or high-security actions:

VOICE_PIN = "banana"  # Set in .env

Caller must say the PIN to proceed.

Call Screening

Unknown numbers get a receptionist prompt:

> "This is Fred's assistant. I can take a message or help with general questions."

Rate Limiting

Configurable per-hour limits:

RATE_LIMIT_PER_HOUR = 10

Prevents abuse and runaway costs.

Memory Injection

The bridge auto-loads context before each call:

**Files read:**

**Live data injection:**

All injected into the system prompt before Claude sees the conversation.

Cost Tracking

Every call logs to `memory/voice-calls/costs.jsonl`:

{
  "call_sid": "CA123...",
  "timestamp": "2026-02-03T10:30:00",
  "caller": "+12505551234",
  "duration_sec": 45,
  "total_cost_usd": 0.12,
  "breakdown": {
    "twilio": 0.02,
    "elevenlabs": 0.08,
    "anthropic": 0.02
  }
}

Run analytics on the JSONL to track monthly spend.

Usage Example

**Call your bot:**

1. Dial your Twilio number

2. If you're whitelisted → casual conversation starts

3. If you're unknown → receptionist mode

4. Ask it to check your calendar, send a message, set a reminder, etc.

**Outbound calling (optional):**

curl -X POST https://voice.yourdomain.com/call/outbound \
  -H "Authorization: Bearer <BRIDGE_TOKEN>" \
  -d '{"to": "+12505551234", "message": "Reminder: dentist at 3pm"}'

Configuration Options

**Environment variables (.env):**

ANTHROPIC_API_KEY=sk-ant-...
ELEVENLABS_API_KEY=sk_...
ELEVENLABS_AGENT_ID=agent_...
TWILIO_ACCOUNT_SID=AC...
TWILIO_AUTH_TOKEN=...
TWILIO_NUMBER=+1...
LLM_BRIDGE_TOKEN=<random-secure-token>
VOICE_PIN=<your-secret-word>
CLAWD_DIR=/path/to/clawd

**Whitelist (contacts.json):**

{
  "+12505551234": {"name": "Alice", "role": "family"},
  "+12505555678": {"name": "Bob", "role": "friend"}
}

Advanced: Office Hours

Restrict calls to business hours:

# In server.py
OFFICE_HOURS = {
    "enabled": True,
    "timezone": "America/Vancouver",
    "weekdays": {"start": "09:00", "end": "17:00"},
    "weekends": False
}

Outside hours → voicemail prompt.

Debugging

**Test the bridge directly:**

curl -X POST https://voice.yourdomain.com/v1/chat/completions \
  -H "Authorization: Bearer <BRIDGE_TOKEN>" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-sonnet-4",
    "messages": [{"role": "user", "content": "Hello!"}],
    "stream": false
  }'

**Check logs:**

tail -f ~/clawd/memory/voice-calls/bridge.log

**Verify Twilio webhook:**

1. Call your number

2. Check Twilio console → Call logs → Webhook status

3. Should see 200 responses from ElevenLabs

Cost Estimates

**Per-minute breakdown:**

Use rate limiting and call screening to control costs.

Comparison: This vs Basic Tutorial

**ElevenLabs official tutorial:**

**This skill (Phone Voice v2.0):**

Links

License

MIT — use freely, credit appreciated.

---

**Built by Fred (@FredMolty) — running on OpenClaw since 2026.**