> ## Documentation Index
> Fetch the complete documentation index at: https://docs.thinnest.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Conference Calling

> Add a third party — supervisor, specialist, or external number — to an active call for a 3-way conversation.

# Conference Calling

The **Conference Calling** tool lets your voice agent add a third party to the current call, creating a 3-way conversation. This is useful for bringing in a supervisor, specialist, or subject matter expert without transferring the caller away.

## How It Works

```
Caller: "This is a complex tax question, can you bring in a specialist?"
Agent: "Absolutely, I'll connect our tax specialist now. Please hold briefly."
-> Agent calls start_conference
-> Supervisor's phone rings, they join the call
Agent: "I have our tax specialist on the line. They can hear our conversation."
```

## Configuration

```json theme={null}
{
  "conferenceCallingEnabled": true,
  "conferenceMaxParticipants": 3,
  "conferenceSupervisorNumber": "+14155551234"
}
```

| Setting                      | Type    | Default | Description                                |
| ---------------------------- | ------- | ------- | ------------------------------------------ |
| `conferenceCallingEnabled`   | boolean | `false` | Enable conference calling                  |
| `conferenceMaxParticipants`  | integer | `3`     | Maximum participants in the call           |
| `conferenceSupervisorNumber` | string  | —       | Default supervisor/specialist phone number |

## LLM Tool

**Tool name:** `start_conference`

Add a third party to the current call.

```
Parameters:
  reason: string (why the third party is being added)

Returns: "Conference started. Adding +1415555**** to the call."
```

The conference is initiated via LiveKit SIP participant addition — the third party's phone rings and they join the existing room.

## Example — Create Agent with Conference Calling

```bash theme={null}
curl -X POST https://api.thinnest.ai/v1/agents \
  -H "Authorization: Bearer $THINNESTAI_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "Support Agent with Conference",
    "model": "gpt-4o",
    "instructions": "You are a support agent. If the caller needs specialized help, use start_conference to bring in a specialist. Always inform the caller before adding someone.",
    "voiceEnabled": true,
    "transcriber": { "provider": "deepgram", "model": "nova-2-conversationalai" },
    "voice": { "provider": "deepgram", "voiceId": "aura-2-thalia-en" },
    "conferenceCallingEnabled": true,
    "conferenceMaxParticipants": 3,
    "conferenceSupervisorNumber": "+14155551234"
  }'
```