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

# Realtime Voice

> Where voice fits in ResponseCX — and where the full Voice platform documentation lives.

# Realtime Voice

ResponseCX agents can answer the phone. An [agent](/response-api-reference/agents) with a
`voice_model` set is a voice agent: the same policies, settings, and functions, delivered over a live
call instead of chat — built on Twilio for telephony and the OpenAI Realtime API for speech.

<Note>
  This page is orientation. The Voice platform — API, SDKs, webhooks, supervision, operations — is
  documented in [StateSet Voice](/stateset-voice/overview).
</Note>

## What a voice interaction looks like

1. **Verify the caller** — email entry plus a one-time password, persisted so a returning caller
   skips it.
2. **Load context** — order history and preferences, so "where's my order?" needs no order number.
3. **Act** — modify an order, manage a subscription, take a payment — through the same
   [functions](/response-api-reference/functions/list) a chat agent uses.
4. **Escalate** — a human supervisor can monitor, whisper, barge, or take over an in-flight call.

## Configure a voice agent

```bash theme={null}
curl -X PUT https://api.stateset.com/v1/agents/{id} \
  -H "Authorization: Bearer $STATESET_API_KEY" \
  -H 'content-type: application/json' \
  -d '{ "voice_model": "gpt-realtime", "activated": "true" }'
```

Number routing, call placement, transcripts, and webhooks are on the
[Voice API](/stateset-voice/api) — the agent record only selects the model.

<Warning>
  A voice agent acts in real time with no review step between utterance and effect. Wire consequential
  actions — refunds, cancellations — through the [decision gate](/stateset-nsr-decisions) *before*
  going live, not after the first bad call. Voice is the surface where "the model decided" is most
  expensive.
</Warning>

## Watch a live call

Supervision is part of the platform, not an afterthought:

```bash theme={null}
# List active sessions, then monitor one
curl https://api.stateset.com/v1/voice/sessions?status=active \
  -H "Authorization: Bearer $STATESET_API_KEY"
```

`session.action` webhook events record every supervisor act — monitor, whisper, barge, escalate —
so the audit trail of who intervened on a call is part of the call record. Details in
[Voice webhooks](/stateset-voice/webhooks#sessions-and-supervision).

## Related

* [StateSet Voice](/stateset-voice/overview) — the platform
* [Voice quickstart](/stateset-voice/quickstart) — a number answering in minutes
* [Voice webhooks](/stateset-voice/webhooks) — call lifecycle events, signed
* [Voice MCP server](/stateset-voice/mcp-server) — drive it from an agent