The term "webhook" was coined by Jeff Lindsay in 2007 from the computer programming term Hook.

A webhook in web development is a method of augmenting or altering the behavior of a web page, or web application, with custom callbacks.

When that event occurs, the source site makes an HTTP request to the URI configured for the webhook.

The subscriber needs to run a web accessible server so that hubs can directly notify it when any of its subscribed topics have updated, using a webhook mechanism.

Because the Evented API is a specialization of the webhook concept, any system that supports webhooks can raise events for KRL.

An endpoint that generates an event may be observing some activity directly and reporting salient state changes or it might just be reporting or transforming event data from another source (e.g., a webhook).