ElevenLabs Voice Agent

---

name: elevenlabs-voice-agent

description: Build and manage ElevenLabs Conversational AI voice agents with Twilio phone integration. Use when creating AI phone agents (cold callers, appointment setters, customer service), configuring voice/LLM settings, connecting Twilio phone numbers, or debugging voice agent issues. Covers NEPQ sales framework, objection handling, and call qualification flows.

version: 1.0.0

---

# ElevenLabs Voice Agent

Build AI phone agents using ElevenLabs Conversational AI API + Twilio.

Setup Flow

1. Create agent via ElevenLabs dashboard or API

2. Configure voice, TTS model, LLM, and system prompt

3. Purchase/connect Twilio phone number via ElevenLabs phone integration

4. Test and iterate on script, voice settings, turn-taking

Optimal Voice Settings (Proven)

| Setting | Value | Why |

|---------|-------|-----|

| TTS Model | v3 conversational | Best quality for phone calls |

| Expressive mode | ON | Natural inflection |

| Stability | 0.45 | Natural variation without inconsistency |

| Similarity | 0.75 | Recognizable voice |

| Speed | 1.2x | Fast enough for cold calls (API max) |

| Streaming latency | 4 | Balance speed vs quality |

| Turn timeout | 2s | Don't wait too long for response |

| Eagerness | eager | Jump in naturally |

| Speculative turn | ON | Faster responses |

| Cascade timeout | 3s | Handle pauses |

Recommended Voices

LLM Choice

Use `gpt-4o-mini` for phone agents — speed is critical, latency kills calls.

Key API Endpoints

POST https://api.elevenlabs.io/v1/convai/agents/create
PATCH https://api.elevenlabs.io/v1/convai/agents/{agent_id}
GET https://api.elevenlabs.io/v1/convai/agents/{agent_id}
POST https://api.elevenlabs.io/v1/convai/twilio/phone-numbers — Connect Twilio number

Enable Phone Features

Enable these tools on the agent: `voicemail_detection`, `end_call`, `background_voice_detection`

NEPQ Sales Framework

For appointment-setting agents, use Neuro-Emotional Persuasion Questioning:

Twilio Integration

1. Get Twilio Account SID + Auth Token

2. Use ElevenLabs API to create phone number connection

3. Phone number is provisioned automatically by ElevenLabs

4. Calls route: Twilio → ElevenLabs → AI agent

Common Issues