# Logging

## Purpose

Make debugging possible.

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# Log Levels

Use:

Trace.

Debug.

Information.

Warning.

Error.

Critical.

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# Do Not Log

Never log:

- Passwords.
- Tokens.
- API keys.
- Private documents.

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# Useful Logs

Include:

- Operation.
- User context where safe.
- Error details.
- Correlation IDs.

## Runtime output

Production emits structured JSON to stdout for Docker collection. Development keeps readable console
and debug output. The request middleware records method, path, status, elapsed milliseconds, trace ID,
and authenticated subject when present. Unhandled errors use the same trace ID in their Problem Details
response so an operator can correlate the client report with `docker logs`.

Compose retains three 10 MB local log files per service. There is no external sink; add Seq/OTLP only
when single-node Docker logs stop being operationally sufficient.