Posts tagged “webhooks”

October 8, 2026·7 min read

Exactly-once is a WHERE clause: surviving duplicate carrier webhooks

Carriers deliver webhooks at least once, out of order, and sometimes twice under different ids. Here is how Handset turns that into one message status, one billed minute, and one event to your endpoint, with a unique index, a handful of guarded UPDATEs, and no dedupe service.

Jose Zamudio