# Voice Assistant

Answer the client's phone line with an AI voice agent — bookings, lookups, handoff

> Full REST + WebSocket API reference: https://api.happ.tools/reference

Connect a SIP phone number and an AI voice agent answers the client's calls — greeting, natural conversation, tools, and human handoff.

<VoicePageDemo />

## Connect voice [#connect-voice]

1. [Set up a phone number](/docs/voice/setup) with SIP credentials (login, password, telephony URL).
2. Connect a [telephony provider](/docs/voice/providers) integration (Binotel, Ringostat, Phonet, Unitalk).
3. Assign an assistant configured for voice; optionally add [ElevenLabs](/docs/voice/providers#elevenlabs-premium-voices) for premium voices.
4. Call the number to test.

The agent can run [webhook tools](/docs/tools) mid-call (bookings, lookups, CRM), trigger `webhook_postcall` follow-ups, and transfer to a human via the built-in `turnOffAiMode` tool. Calls are recorded and transcribed when the provider supports it.

## Settings [#settings]

| Setting                | Behavior                                   |
| ---------------------- | ------------------------------------------ |
| Eagerness: Eager       | Responds quickly, best for simple Q\&A     |
| Eagerness: Normal      | Balanced timing (default)                  |
| Eagerness: Patient     | Waits longer, best for complex questions   |
| Voice                  | 30 built-in voices, or ElevenLabs premium  |
| Codec: A-law (default) | Standard international telephony, 8000 Hz  |
| Codec: μ-law           | Standard North American telephony, 8000 Hz |

**API:** [api.happ.tools/reference](https://api.happ.tools/reference)

## Next [#next]

* [Set up a phone number](/docs/voice/setup) — SIP credentials
* [Telephony providers](/docs/voice/providers) — Binotel, Ringostat, Phonet, Unitalk, ElevenLabs
* [Configure tools](/docs/tools) — actions during calls