Webhook vs REST API: Push vs Pull Explained

A REST API is pull: your app makes a request whenever it wants data or wants to act. A webhook is push: the source sends you data automatically when an event happens. They are complementary rather than competing. You typically call a REST API to fetch or change data on demand, and you register a webhook to be notified in real time instead of polling that same API on a loop.

Webhooks vs REST API at a glance

Webhooks (push)REST API (pull)
Who starts the exchangeThe source, on an eventYour app, on demand
TimingReal-time when something changesWhenever you choose to call
Best forBeing notified of eventsFetching or modifying data
Real-time costOne request per eventConstant polling to stay current
DirectionSource to your endpointYour app to the source

When to use each

Use a REST API when you need to request specific data or perform an action at a time you control.

Use webhooks when you need to know about changes as they happen without polling. For real-time integrations the two work together: the webhook tells you an event occurred, and you often call the REST API to fetch the full record behind it.

How Hookdeck fits

Choosing webhooks over constant REST polling trades wasted requests for delivery responsibility: retries, signature verification, ordering, and visibility into failures. Hookdeck's Event Gateway provides that layer so you get real-time push without building the reliability plumbing, and you can still call the source's REST API for the details. See the Event Gateway, or replay and inspect payloads with the CLI.