delivery(event, metadata):
event is the same parsed public JSON object you receive from a webhook for the same source occurrence and API version. Its identity, type, data, and extension fields are preserved. Whitespace and property order are not part of this transport’s contract.
metadata describes this delivery: seq is its replay cursor, and replyExpected indicates whether this connection may submit a synchronous reply. Metadata is separate from the event object.
Deliveries have no processing acknowledgement callback. Receipt does not prove your handler completed. Process events in order and save only a successfully handled cursor. A reconnect can redeliver an event; make handling idempotent.