recall

← recall

webhook pattern

Server pushes events to a URL the client previously registered. Real-time delivery, but you've inverted the trust boundary — the server now makes outbound calls into your network.

Server pushes events to a URL the client previously registered. Real-time delivery, but you've inverted the trust boundary — the server now makes outbound calls into your network.

symptoms

  • lost events when receiver is down
  • duplicate deliveries on retry
  • auth complexity (verifying sender)

causes

  • polling too slow / wasteful
  • need real-time event push

fixes

  • idempotent receivers
  • signature verification (HMAC)
  • retry with backoff on non-2xx
  • dead-letter for unrecoverable deliveries

you might say

  • fire a webhook
  • register a callback URL

related

aliases: callback url, reverse api

topics: api-design

references: