Webhooks appear simple until a provider retries an event, delivers it out of order, or times out after your system already processed it. Without explicit handling, customers see duplicate actions, missing updates, and state that disagrees with the source system.
Reliable webhook consumption assumes delivery is asynchronous and imperfect. This guide covers authentication, durable ingestion, idempotency, ordering, retries, and reconciliation for integrations that must survive routine failures.
Authenticate before processing
Verify signatures against the raw request body, enforce timestamp tolerances, and rotate secrets safely. Use HTTPS and restrict payload size. Return generic responses to invalid requests while preserving enough internal evidence to investigate attempted abuse.
Acknowledge after durable receipt
Validate the envelope, persist the event or enqueue it durably, and respond quickly. Move business processing out of the request path. This prevents slow dependencies from causing unnecessary retries and separates provider delivery health from internal workflow health.
Make processing idempotent
Store stable event identifiers or enforce uniqueness on the resulting business operation. Handle duplicate and out-of-order events by checking authoritative state and transition rules. Retries need bounded exponential backoff, dead-letter handling, and a documented replay process.
Reconcile periodically
Webhooks are notifications, not always a complete ledger. Query the provider or compare records to recover missed events and confirm final state. Test duplicates, delayed delivery, invalid signatures, and handler crashes before launch; then expose operational tools for safe inspection and replay.