What is a Webhook?

Webhooks are automated messages sent from web pages or apps to notify when something happens.

In web development, webhooks add or alter the behavior of web pages or web applications with custom callbacks. Callbacks can, in turn, be maintained, modified, and managed by 3rd-party users and developers who are not part of the core development team of the application or page in use. Webhooks are usually written in JSON, and requests are done as HTTP POST request.

How do webhooks work?

Events trigger webhooks, for example when a new component is pushed to a repository or page.

When events occur, the source site makes an HTTP request to the URL configured for the webhook. Users can configure them to cause events on one site to invoke further actions. Habitual uses include building triggers for continuous integration systems and notify bug tracking systems.

Because webhooks use HTTP, they can be easily integrated into web services without adding new infrastructure, making them widely used.

What are webhooks used for?

Webhooks notify the occurrence of an event in one system to another. For example, you have subscribed to content that charges your card monthly. That service wants to send you a message each time it charges your credit card. So, that service subscribes to banks’ service to send a webhook when charging a credit card to their emailing service. The bank’s service is the source, the triggered event is a credit card charge, and the destination is the streaming email service.

What is the difference between API and webhook?

Webhooks are a subset of the APIs, meaning they are more limited, while APIs are more versatile. Webhooks automatically send data in response to a specific event without any request from another software. On the other hand, APIs are manual.

Dec 10th, 2021
2 min read