Assignment removed
An assignment was removed entirely: deleted by your team (revoked), unassigned before it started (cleared), or removed when its campaign ended or was deleted, the creator was archived, or the plan lapsed. assignment is its last state; periods it covered are no longer due.
Headers
The event id; the same on every retry of this event. Dedupe on it.
Unix seconds of this delivery attempt (re-signed on every retry). Reject values more than 5 minutes off.
Space-separated v1,<base64 HMAC-SHA256 of "<webhook-id>.<webhook-timestamp>.<body>"> signatures, one per active signing secret (two during a rotation). Verify with any Standard Webhooks library.
Payload
Response
Any 2xx within 15 seconds acknowledges the event. Anything else, a timeout or a redirect is retried (10 attempts over about 3 days); 410 disables the endpoint.
Changes
Webhooks have no change history: a webhook is keyed by its event name rather than a path and method, so no recorded change can name it.