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

# Webhooks

> Events the platform can send you.

The platform can POST signed events to one URL per workspace.

<Warning>
  **Today exactly one event exists: `call.completed`**, emitted when an
  outbound phone task reaches a terminal state.

  There are no conversation, message, order or booking events yet. If your
  product needs to react to something a conversation did, it cannot subscribe
  to it — design around tools being called, and tell us what you need.
</Warning>

## Verifying a delivery

Header, Stripe-style:

```
X-Tegain-Signature: t=1717171717,v1=<hex>
X-Tegain-Event: call.completed
X-Tegain-Delivery-Id: <uuid>
```

Signed string is `{timestamp}.{raw body}`, HMAC-SHA256 with the workspace
webhook secret.

```python theme={null}
import hmac, hashlib

def verify(raw_body: bytes, header: str, secret: str, tolerance: int = 300) -> bool:
    parts = dict(p.split("=", 1) for p in header.split(","))
    ts, sig = parts.get("t", ""), parts.get("v1", "")
    if abs(time.time() - int(ts)) > tolerance:
        return False                      # replay window
    expected = hmac.new(secret.encode(), f"{ts}.".encode() + raw_body,
                        hashlib.sha256).hexdigest()
    return hmac.compare_digest(expected, sig)
```

<Note>
  Verify against the **raw bytes**, not a re-serialised object. The platform
  signs exactly what it sends.
</Note>

## Delivery behaviour

|                |                                        |
| -------------- | -------------------------------------- |
| Retries        | 3 attempts, backing off 60s / 5m / 30m |
| 4xx            | Permanent failure, no retry            |
| 5xx or timeout | Retried                                |
| Timeout        | 5 seconds                              |
| Replay window  | 5 minutes                              |

Deliveries are listed in the dashboard and can be replayed by hand.

<Warning>
  Webhooks require a plan that includes them; without it, events are silently
  not enqueued.
</Warning>