What is Webhook?
A webhook is a way for one service to notify another in real time by sending an HTTP request (usually a POST) to a URL you provide whenever a specific event happens. Instead of you repeatedly polling for changes, the service pushes the data to you.
Webhook payloads are often signed (e.g. with an HMAC) so the receiver can verify they are authentic and untampered.
Key points
- A service POSTs to your URL when an event occurs.
- Push-based — no polling required.
- Payloads are usually JSON and often HMAC-signed.
- Your endpoint should respond quickly and verify the signature.
Example
POST /webhooks/stripe
X-Signature: t=...,v1=...
{ "type": "payment.succeeded" }Common uses
- Payment notifications (Stripe, PayPal)
- CI/CD triggers from Git pushes
- Chat and alerting integrations
- Syncing data between services in real time