Webhook Reliability Checklist

When to Use This Checklist

Use this checklist when building or consuming webhooks, the HTTP callbacks one system uses to notify another of events. Webhooks look simple but are a distributed system: networks fail, receivers time out, and events arrive duplicated or out of order. This checklist covers the controls that make webhook delivery dependable on both sides.

How to Use This Checklist

Start with security: sign payloads and verify signatures, and include a timestamp to block replay. On the receiver side, make handling idempotent with a stable event ID, since retries will deliver duplicates. Return quickly and process asynchronously so slow work does not cause timeouts and unnecessary retries. Add backoff retries and a dead-letter path on the sender, and monitor delivery success so failures are visible.

What Good Looks Like

Reliable webhooks are signed and timestamped, and receivers verify both before processing. Receivers are idempotent on a stable event ID and tolerate out-of-order delivery. Senders retry with exponential backoff and dead-letter permanent failures, while receivers acknowledge fast and process asynchronously. Delivery success rate, latency, and failure reasons are monitored, and consumers can view an event log and trigger manual redelivery.

Common Pitfalls

The most common failure is non-idempotent receivers that double-process retried events. Skipping signature verification lets attackers forge events. Doing heavy work synchronously causes timeouts that trigger storms of retries. Assuming ordered delivery corrupts state when events arrive out of order. Finally, no monitoring means silent delivery failures that consumers discover days later.

Related Resources

Review webhook best practices, idempotency keys, API rate limiting, the circuit breaker pattern, and structured logging.