Webhook

A callback pattern where one service notifies another by sending an HTTP POST to a URL the receiver registered in advance — triggered by an event, not a poll.

Example: Stripe POSTing to your `/webhook` endpoint when a payment succeeds, instead of you polling Stripe every second.

In practice: Webhooks fail silently if the receiving endpoint is down — retry logic, signature verification, and idempotent handlers are the standard hygiene a receiver needs.

• often confused with WebSocket
• builds on REST