Retries and failures

Retries and failures

What happens when your endpoint is down or slow.

A delivery succeeds when your endpoint replies with any 2xx status within 10 seconds. Anything else is a failure: other statuses, timeouts, TLS errors and refused connections.

After a failure, Heizen tries again on this schedule:

AttemptAfter the previous one
21 minute
35 minutes
430 minutes
52 hours
66 hours
712 hours

That is seven attempts over about 21 hours. After the seventh failure the delivery stays failed.

Recovering

  • Each attempt is listed under the endpoint in Developers → Webhooks, with your response status and body.
  • Replay sends any past delivery's event again, once your endpoint is fixed.
  • To catch up in bulk, page through GET /v1/events from the time the outage started.

Disabling an endpoint

A disabled endpoint receives nothing, and its pending retries are dropped. Re-enabling it does not resend what it missed; replay those deliveries or read them from the Events API.