webhook
termweb devprogramming
An arrangement where one system calls a URL you provide when something happens, instead of you polling to ask.
It inverts who initiates, and that inversion carries three obligations people discover late. The endpoint is public, so it must authenticate the caller - usually by verifying a signature over the body, because a URL is not a secret. Delivery is at-least-once, so the handler must be idempotent or duplicates become double charges. And the sender expects a fast answer, so real work belongs on a queue rather than in the request, or a slow handler turns into retries that make the load worse.
Also known as: callback url