What is a Webhook?
Think of a webhook as a doorbell for software. If you’re waiting for a courier, you don’t go outside every two minutes to check. Instead, the courier rings the bell once they arrive. That “ring” is the notification you need. A webhook works in the same way: it’s a message sent automatically when something important happens, so that another system knows about it right away.
Everyday Example
Let’s say you place an order on Blinkit and pay with UPI. When the payment goes through, the payment gateway immediately sends Blinkit a webhook saying “Payment successful.” Blinkit doesn’t have to keep asking the gateway again and again—it just waits for the webhook and then updates your order.
Technical Side
A webhook is really just an HTTP POST request to a specific URL that you set up. The request carries event data—like “payment captured” or “payment failed.” Your server reads it and acts accordingly: update the database, send an email, ship a product, etc.
Why They Matter
- Real-time updates: Things happen instantly without waiting or refreshing.
- Automation: Triggers workflows automatically, like sending receipts or alerts.
- Efficiency: Saves resources compared to constant checking (polling).
Challenges & Good Practices
- Duplicates: Webhooks might be sent multiple times. Always check the event ID to avoid repeating work.
- Security: Verify signatures so no one can send fake webhooks.
- Retries: Gateways retry if your server doesn’t respond. Make sure your endpoint is reliable and fast.
- Logs: Store what you receive for debugging and compliance.
See It in Action
This demo shows a simple order and payment process. Watch how the order moves from pending to success or failure, and how retries work.
See it in Action
This simulates an order + payment, the webhook callback, and how your Order DB state changes. Try success, failure, and retry.