webhook-consumptionlisted

# Webhook consumption A webhook endpoint is an unauthenticated public write path until you verify it, and providers deliver at least once with no ordering guarantee. Both facts must be designed for rather than discovered. ## Method 1. **Verify the signature before anything else.** An endpoint that acts on unverified payloads can be driven by anyone who knows the URL (see mcp-security-boundaries). 2. **Respond immediately and process asynchronously.** Acknowledge within the provider's timeout and queue the work, since slow processing causes retries and duplicates. 3. **Deduplicate by event id.** Redelivery is normal, and processing a payment event twice is the failure this prevents (see idempotency). 4. **Do not assume order.** Events arrive out of sequence, so use timestamps or version numbers in the payload rather than arrival order (see delivery-guarantees). 5. **Handle unknown event types gracefully.** Providers add types, and an endpoint that errors on unrecognised events generates retries and alerts for no reason. 6. **Reconcile periodically against the provider's API.** Webhooks get lost, so a scheduled comparison catches what the push missed (see payment-reconciliation). 7. **Monitor delivery failures from both sides.** Their dashboard and your error rate together, since a silently failing endpoint looks identical to no events. ## Boundaries Webhooks are best effort even from good providers, which is why reconciliation is not