Skip to main content
Architecture & Engineering

Webhooks

Webhooks are HTTP callbacks that one system sends to another when an event occurs, so the receiver learns about it immediately instead of polling for changes. The receiver exposes a URL, the sender posts event data to it, and the receiver acknowledges with a success response.

Webhooks replace polling, which is wasteful in both directions — most polls return nothing, and the interval determines how stale the data can be. A webhook delivers the change as it happens, at the cost of requiring a publicly reachable endpoint that must stay available.

Reliable webhook handling has three requirements that are commonly missed. Verify the signature, or anyone who learns the URL can post fabricated events. Respond quickly and process asynchronously, because senders time out and retry. And handle duplicates, since at-least-once delivery means the same event will sometimes arrive twice.

Codazz builds this in production — API & Backend Development.

FAQ

Webhooks
FAQ.

Common questions about webhooks.

Ask Us Anything

Verify the cryptographic signature the sender includes, computed over the raw request body with a shared secret — and verify it against the raw bytes, because re-serialising the JSON changes them and breaks the check. Then reject events with old timestamps to prevent replay, and treat the payload as untrusted input regardless.

Related terms

Message Queue

A message queue holds tasks that one part of a system produces and another consumes later, decoupling the two so the producer does not wait for the work to finish.

Event-Driven Architecture

Event-driven architecture is a design where components publish events describing something that happened, and other components react to them, without the publisher knowing who is listening.

Rate Limiting

Rate limiting caps how many requests a client can make in a given period, protecting a service from being overwhelmed by a single caller — whether malicious, misconfigured or simply busy.

Browse the full glossary →