What this error means

{"message": "User not found.", "code": 401} — returned for expired API keys is a OpenRouter failure pattern reported for developers trying to fix openrouter api returning 'user not found' instead of 'key expired' for expired api keys. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

GitHub issue on OpenRouterTeam/docs reports that expired API keys return {'message': 'User not found.', 'code': 401} instead of {'message': 'Key expired.', 'code': 401}. This misleads developers into thinking their account doesn't exist rather than their key being expired.

Common causes

  • OpenRouter returns a misleading 401 'User not found' error when an API key has expired, instead of the expected 'Key expired'. This sends developers on a wild goose chase debugging account issues instead of simply refreshing their key. Reported on official OpenRouter docs repo.
  • GitHub issue on OpenRouterTeam/docs reports that expired API keys return {'message': 'User not found.', 'code': 401} instead of {'message': 'Key expired.', 'code': 401}. This misleads developers into thinking their account doesn't exist rather than their key being expired.

Quick fixes

  1. Confirm the exact error signature matches {"message": "User not found.", "code": 401} — returned for expired API keys.
  2. Check the OpenRouter account, local tool state, and provider configuration involved in the failing workflow.
  3. Verify the account session, API key, provider settings, and environment where the failing tool is running.

Platform/tool-specific checks

  • Verify the command, editor, extension, or API client that produced the error.
  • Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
  • Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

  1. Capture the exact error message and the command, editor action, or request that triggered it.
  2. Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
  3. Review the source evidence below and compare it with your environment.
  4. Apply one change at a time and rerun the smallest failing action.
  5. Keep the working fix documented for the team or deployment environment.

How to prevent it

  • Keep provider/tool configuration documented.
  • Record non-secret diagnostics such as tool version, provider name, model name, and command path.
  • Add a lightweight check before CI or production workflows depend on the tool.