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

# SIP Webhooks and Prewarm

> SIP bridge webhook, status, and prewarm endpoints.

Burki exposes root-level SIP endpoints used by SIP carriers and the SIP bridge. These endpoints do not use the `/api/v1` prefix.

```text theme={null}
https://api.burki.dev/sip-webhook
https://api.burki.dev/sip-status
https://api.burki.dev/sip-prewarm
```

The SIP bridge that terminates customer PBX/carrier traffic currently advertises:

```text theme={null}
SIP bridge IP: 52.21.157.171
SIP signaling: UDP/TCP 5060
SIP TLS: TCP 5061, if enabled
RTP media: UDP 10000-20000
```

PBX/carrier firewalls should allow `52.21.157.171` for both inbound calls to Burki and outbound calls from Burki. The HTTP endpoints above are backend/provider coordination endpoints; customer PBXs should send SIP traffic to the SIP bridge IP, not to `/sip-webhook` directly.

## SIP Webhook

```http theme={null}
POST /sip-webhook
```

Receives SIP inbound call and provider event payloads. This endpoint is called by the SIP bridge/provider layer, not by normal application clients.

## SIP Status

```http theme={null}
POST /sip-status
```

Receives SIP status callbacks for call lifecycle tracking.

## SIP Prewarm

```http theme={null}
POST /sip-prewarm
Content-Type: application/json
```

The SIP bridge calls this endpoint before media streaming so Burki can prepare call context.

### Request

```json Request theme={null}
{
  "call_sid": "sip-20260430-abc123",
  "from_number": "+15559876543",
  "to_number": "+15551234567",
  "outbound": false,
  "assistant_id": 123,
  "welcome_message": "Thanks for calling. How can I help?",
  "agenda": "Customer support intake",
  "variables": {
    "customer_id": "cust_123"
  }
}
```

| Field             | Type                  | Required | Description                                   |
| ----------------- | --------------------- | -------- | --------------------------------------------- |
| `call_sid`        | string                | Yes      | Burki/SIP call identifier used for the stream |
| `from_number`     | string                | No       | Caller phone number                           |
| `to_number`       | string                | No       | Destination or assistant phone number         |
| `outbound`        | boolean               | No       | Whether this is an outbound SIP call          |
| `assistant_id`    | integer               | No       | Assistant to prepare                          |
| `welcome_message` | string                | No       | Optional first assistant message              |
| `agenda`          | string                | No       | Optional call agenda/instructions             |
| `variables`       | object or JSON string | No       | Runtime variables for the call                |

### Response

```json Response theme={null}
{
  "call_sid": "sip-20260430-abc123",
  "prewarmed": true
}
```

### Error Responses

```json 400 theme={null}
{
  "error": "call_sid required"
}
```

## Operational Notes

* `/sip-webhook` and `/sip-status` are CSRF-exempt provider endpoints.
* `/sip-prewarm` is intended for SIP bridge integrations before media streaming.
* SIP bridge synchronization uses `SIP_BRIDGE_URL` and `SIP_BRIDGE_API_KEY` on the backend.
* The bridge sync API receives org config at `POST {SIP_BRIDGE_URL}/api/sync-organization`.