I'm building an error tracker, and I needed to know what an official Sentry SDK does when my ingest answers "you're over quota". I couldn't find anyone showing the wire, so I put a stub server in front of @sentry/node and logged every request it got.

The failure is silent. A Sentry issue from 2025 says users "struggle with “why isn’t it working”" until someone sends them to the Stats & Usage page. Nothing throws. Events just stop showing up.

Node v24.22.1, @sentry/node 11.11.0 ( run-0-versions.txt ), all local on 2026-11-09. The server is a 55-line stub I wrote, not Sentry. What Sentry's servers do comes from their public docs.

TL;DR

After one 429 with X-Sentry-Rate-Limits: 60:error:organization:usage_exceeded , I captured 10 errors and only 3 hit the wire: 2 accepted, 1 rejected. The other 7 never left the process. No queue, no retry, and one warn-level debug line.

The SDK backs off for exactly what the header says. With a 5s window it sent one probe every ~5s.…