Glossary
Webhook
Real-time, event-driven messages between applications
What is a Webhook?
A webhook is an automated message that one application sends to another the moment a specific event happens. Technically, it is an HTTP request (usually a POST with JSON data) sent to a URL you provide - sometimes called an HTTP callback or "reverse API."
The difference from a normal API call is direction. With an API, your application asks for data and waits for an answer (pull). With a webhook, the other system pushes data to you the instant something changes, so there is no need to repeatedly poll and ask "anything new yet?" This makes webhooks fast and efficient for event-driven integrations.
How Webhooks Work
- Register a URL - You give the sending service an endpoint on your server
- Event occurs - A payment succeeds, an order is placed, a form is submitted
- Payload sent - The service POSTs event details to your URL in real time
- Verification - Signatures or secrets confirm the request is genuine
- Your code reacts - Update a record, send an email, trigger the next workflow step
Webhooks in Practice
- Payments - Stripe webhooks confirm successful payments; CCMS products like TUITIONsimple and STORAGEsimple use them to activate subscriptions automatically
- E-commerce - WooCommerce fires webhooks on new orders to sync with shipping, stock, and CRM systems
- Notifications - Post alerts to Slack or Teams when something needs attention
- Automation platforms - Zapier and Make connect thousands of apps using webhooks under the hood