What is a Webhook

Typical flow for a webhook

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What is a Webhook?

Webhook is nothing but user-defined HTTP callbacks where you can receive event driven notifications from us. This way you can get real-time information as soon as it happens. That’s the bedrock of building a robust 2-way communication system at your end.

Webhook operates on the concept of event reaction (don’t call me, I’ll call you if I have something new), and thus avoids the need for constant polling of the server-side application by the client-side application. Thus, rather than the client-side application constantly polling the server-side application to check for new events, the server-side application calls the client-side application (by invoking a client provided webhook URL) anytime the server-side has something new to report to the client.

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How is it different from an API?

In API calls the server-side application provides the client-side application with end-point URLs that the client-side application can call.

In case of Webhooks, it is the client-side application that provides the server-side application with a URL to call, and the server-side application calls that URL, when some relevant server-side event has occurred. So a webhook is simply an end-point URL provided by the client-side application to the server-side application.

{ "url": "https://client.webhooklabs.com" }