You'll noticeTier: how much it should matter to you
3Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
AuthArea: what it touches
ImprovementsKind: in v2.1.227,
ImprovementsSection of the release
What
When a request is rejected and the credentials came from headers rather than a plain API key, the error now names the actual source: ANTHROPIC_CUSTOM_HEADERS, an external auth token, or an external API key, with the server's own message appended after a middot.
Details
Previously these fell through to the generic x-api-key wording, which pointed at a setting the user was not using.
Credentials from a managed key or from a claude.ai login are classified as an authentication failure instead.
