Request a terminal callback
Supply an HTTPS webhookUrl with task submission. The receiver must be publicly reachable; local, private and unsafe destinations and redirects are rejected. Polling remains available when no callback is configured.
Receive a notification
Callbacks are unsigned JSON POST requests. The X-SpriteFlow-Event-Id header matches the body's id; use it to deduplicate deliveries. Use an authenticated task query with your Bearer API key to confirm the current result.
Process one terminal event
A terminal event contains the stable event ID, type, creation time and task result snapshot. A batch emits one aggregate terminal event after every child is terminal, including partial success when applicable. Event data includes asset IDs rather than expiring download URLs. Fetch the authorized download URLs separately.
The snapshot uses the same result structure as task queries, without the webhook delivery field. Refund flags reflect the ledger at event creation; refunds can settle afterwards. Query the original task again for the latest refund state. Redelivery keeps the original event bytes unchanged.
Redelivery
Return a 2xx response promptly after durably accepting the event. Network failures, 429 and server errors are retried by the persistent workflow, for up to eight attempts. Other non-2xx responses stop delivery. Delivery is at least once; use the same event ID as the deduplication key. Read the task's webhook object to inspect attempts and final delivery state.