SigNoz Cloud wants a signoz-ingestion-key header, not an Authorization header

TL;DR

If only some signals arrive, verify each signal's endpoint path separately instead of assuming one working path covers all. Port 4318 is already in use when another tool like Phoenix claims SigNoz's default OTLP HTTP port; the bundled compose remaps SigNoz to 4328.

Steps

1. When 4318 is taken, move SigNoz's OTLP HTTP port rather than fighting the other tool. For SigNoz Cloud, send the ingestion key in the signoz-ingestion-key header. If only some signals arrive, verify each signal's endpoint path separately instead of assuming one working path covers all.

When to use

You are seeing this: When 4318 is taken, move SigNoz's OTLP HTTP port rather than fighting the other tool. Use this skill when you run into "SigNoz Cloud wants a signoz-ingestion-key header, not an Authorization header".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

Source: A SigNoz backend guide documents the endpoint mix-ups. Port 4318 is already in use when another tool like Phoenix claims SigNoz's default OTLP HTTP port; the bundled compose remaps SigNoz to 4328. Cloud ingestion returning 401 with a missing key often means the header was wrong: SigNoz Cloud wants signoz-ingestion-key, not Authorization. When metrics show up but traces do not, the traces endpoint is likely wrong while the metrics path derived from it is right, so double-check the trace path.

Verified resolution: When 4318 is taken, move SigNoz's OTLP HTTP port rather than fighting the other tool. For SigNoz Cloud, send the ingestion key in the signoz-ingestion-key header. If only some signals arrive, verify each signal's endpoint path separately instead of assuming one working path covers all.

Source URL: https://github.com/briancaffey/hermes-otel/blob/HEAD/website/docs/backends/signoz.md