What is a Webhook? A Simple Tutorial for Developers

A webhook is a mechanism that allows one application to send real-time data to another whenever a specific event occurs. Unlike traditional APIs where you poll for updates, webhooks push data automatically, making them efficient for event-driven integrations.

How Webhooks Work

To set up a webhook, you provide a URL (the webhook endpoint) to the source application. When the event triggers, the source sends an HTTP POST request to that URL with a payload containing event details. Your server then processes this data.

Key steps to implement a webhook receiver:

• Create an endpoint that accepts POST requests.
• Validate the request (e.g., using signatures).
• Parse the payload and trigger your logic.
• Respond with a 2xx status to acknowledge receipt.

Webhooks vs. APIs

With a REST API, you must repeatedly poll for changes, which wastes resources. Webhooks eliminate polling by pushing data only when events happen. This reduces latency and server load, making webhooks ideal for real-time notifications.

Common Use Cases

• CI/CD: Trigger builds on code pushes.
• Payments: Notify your app of successful transactions.
• Chat: Send messages to Slack or Discord.

Webhooks are a powerful tool for building reactive systems. By understanding how they work, you can integrate services efficiently and avoid unnecessary polling.