Reliability & Resilience
Webhooks fail. Networks are unreliable, servers go down, and deployments cause outages. These guides cover the patterns and strategies for building webhook systems that handle failure gracefully.
What makes webhooks reliable
Webhook reliability comes from four mechanisms built around a plain HTTP POST: retries with exponential backoff and jitter, usually about eight attempts over 24 hours; a dead letter queue for deliveries that exhaust them; a stable message ID on every request so receivers can drop duplicates; and per-endpoint timeouts and circuit breakers so one failing receiver cannot delay the rest.
| Failure | Mechanism | Guide |
|---|---|---|
| Receiver briefly down or deploying | Retries with exponential backoff and jitter | Webhook retry strategies |
| Receiver too slow to answer | Short delivery timeout, respond 2xx first, process after | Webhook timeout best practices |
| Same event delivered twice | Idempotent handlers keyed on the message ID | Idempotency and deduplication |
| Retries exhausted | Dead letter queue with replay | Dead letter queues |
| One endpoint failing for days | Circuit breaker that pauses delivery to it | Circuit breakers |
| Unclear what “delivered” promises | At-least-once semantics, stated explicitly | Webhook delivery guarantees |
For the numbers to expect from a provider, see how reliable are webhooks and the concrete schedule in our retry best practices.
Webhook retry strategies
Webhook retry strategies that work: exponential backoff schedules, jitter to prevent thundering herds, and knowing when to stop retrying failed deliveries.
Idempotency and Deduplication
Idempotency and deduplication for webhooks: why duplicate deliveries happen and how to track event IDs so your handler processes each event exactly once.
Webhook Timeout Best Practices
Webhook timeout best practices: why providers cut you off in 5-30 seconds, and how the acknowledge-first pattern keeps handlers fast and avoids retries.
Webhook Delivery Guarantees
Webhook delivery guarantees compared: what at-least-once, at-most-once, and exactly-once mean in practice, and how each affects your webhook consumer.
Dead Letter Queues for Webhooks
Dead letter queues for webhooks: capture deliveries that exhaust their retries, decide which failures belong in the DLQ, and replay them safely.
Circuit Breakers for Webhook Delivery
Circuit breakers for webhook delivery: how the closed, open, and half-open states stop retry storms against failing endpoints, with a Python implementation.