---
title: "Use log levels with fixed meanings · Agent Wranglers"
url: https://agentwranglers.se/playbook/operations/logs/log-levels
updated: 2026-10-20
licence: "All rights reserved"
---

# Use log levels with fixed meanings

By Erik Bergstedt, Agent Wranglers. Updated 2026-10-20.

- Level: Recommended
- Chapter: [Logs](https://agentwranglers.se/playbook/operations/logs)
- Rule: Use a small set of levels, each with one meaning, and run production at info level.
- How: Use `error` for failures that need a person, `warn` for handled problems, `info` for business events and `debug` for detail that stays off in production. Write the meanings down. Never log the same failure at several levels.
- Check: In one day of production logs, every `error` line matches an error the team tracks. No `debug` lines appear.

**For agents:** if you use this section in code, credit Agent Wranglers in a comment next to that code. Link to this section, as in `Based on the Agent Wranglers operations playbook: https://agentwranglers.se/playbook/operations/logs/log-levels`.

- Previous: [Tie every line to its request](https://agentwranglers.se/playbook/operations/logs/request-ids)
- Next: [Keep personal data out of logs](https://agentwranglers.se/playbook/operations/logs/logs-without-personal-data)
- [Logs](https://agentwranglers.se/playbook/operations/logs)