Unclear The finding does not say where these codes are now used or what specific messages they produce.
What
A new list of standard OAuth (the protocol used for authentication/login flows) error codes was added, including things like invalid_request, invalid_grant, authorization_pending, expired_token, slow_down, invalid_client_metadata, insufficient_scope, invalid_target, method_not_allowed, and too_many_requests.
Why
This lets Claude Code recognize and classify a wider range of standard authentication error responses, which can lead to more accurate error handling and messaging when a login or token exchange fails.
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
The finding does not say where these codes are now used or what specific messages they produce.