Webhook, explained
Webhooks reverse the usual direction of an API: instead of polling, the consumer receives events such as payment.succeeded. Providers typically sign payloads so receivers can verify them, and retry deliveries that fail.
Renaming an event type or changing a payload is a breaking change for every receiver, and one that is easy to miss because webhook handlers are often the least-tested code in an integration.
Related terms
- Idempotency: An API operation is idempotent when performing it multiple times has the same effect as performing it once, which makes retries safe.
- Breaking change: A breaking change is a change to an API that causes a correctly written client, which worked before, to fail or behave differently without modifying its code.
- API: An API (application programming interface) is a defined contract that lets one piece of software request data or actions from another without knowing how it is implemented.