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The v1 docs follow nauthera-server's main branch and its 0.x releases on the way to 1.0, so fields and APIs can still change.

v1

unsupported_grant_type

Docs version v1 (main)Nauthera is pre-1.0, in a design-partner program

The token request named a grant type this server does not implement (RFC 6749 §5.2).

Meaning

Sent by /token when grant_type is none of authorization_code, refresh_token, client_credentials and urn:ietf:params:oauth:grant-type:device_code, nor one of the two grants answered temporarily_unavailable (token exchange and JWT bearer). The client authenticated first, so the refusal is filed against it.

Impact

The client cannot get a token this way at all. It is a client bug: a typo in the grant type, a grant from another server, or the password or implicit flow, which this server does not offer.

Diagnosis

  1. Look at the grant_type the client sent: the audit record under oauth.token.issued carries it as grant_type, with reason unsupported_grant_type. Find it by X-Request-ID on the Troubleshooting page.
  2. The grants this server serves are listed in grant_types_supported in the discovery document.

Mitigation

  • As a client developer: use one of the supported grants, spelled exactly; the device grant takes the full URN.
  • As an operator: nothing to change on the server.
  • As a user: tell the application's owner.

Escalation

If a grant listed in the discovery document is answered this way, open an issue with the request id, the server version and the grant type sent.

OAuth error runbooks · Generated from internal/runbook/oauth.yaml in nauthera-server.