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

# Webhook events

> Understand event names and webhook payloads.

Event names use lowercase `snake_case`. For example, outbound fax webhooks use `outbound_fax`.

```json theme={null}
{
  "event_id": "evt_abc123xyz789",
  "event_type": "outbound_fax",
  "occurred_at": "2026-08-22T08:23:28Z",
  "data": {
    "fax": {
      "direction": "outbound",
      "fax_uuid": "XXXXXXXXXXXXXXXX",
      "transmission_duration": 59,
      "transmission_start": "2023-11-10T00:00:34Z",
      "transmission_end": "2023-11-10T00:01:33Z",
      "pages": 1,
      "fax_status": "Delivered",
      "from_number": "19073331000",
      "to_number": "19073331000",
      "transferred_pages": 1,
      "retry_attempt": 0
    }
  }
}
```

The `data` object contains one property named for the affected resource. Its value contains the fields relevant to that event. Date and timestamp fields use ISO 8601 UTC strings.

Your integration should ignore unknown fields and safely handle new event types.