Collapse retries with deduplication
identifier mode keys on the Standard Webhooks webhook-id (or a recognized provider event id), so a provider retry within the window collapses into the event you already have. See deduplication.Deliver to fulfillment, signed and verified-only
Register fulfillment as a destination, then subscribe
--require-verified. Each delivery is signed with the destination secret and retried on the fixed schedule (5s → 5m → 30m → 2h → 5h → 10h → 10h); after 20 dead deliveries the destination auto-disables so a hard outage stops hammering it.