message.failed

An outbound message failed permanently. Payload error_message / error_details describe the platform error.

postWebhookmessage.failed

Payload

idstring required

Delivery ID, prefixed with whevt_. Matches the X-Postproxy-Delivery header.

object'event' required

Always "event".

typestring required

Event type (e.g. platform_post.published). Matches the X-Postproxy-Event header.

created_atstring required

ISO 8601 timestamp of when the event was generated.

Acknowledged

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.