The Authentication API returns RFC 9457 problem documents with Content-Type: application/problem+json. Every response carries an absolute type URI that resolves to a page on this site.

The URI is built from the template owned by the authentication contract:

https://docs.zeroset.com/problems/{code}

• access_denied — Device authorization denied (403)
• authorization_pending — Waiting for approval (400)
• binding_conflict — Collection assignment conflict (409)
• configuration_invalid — Configuration invalid (503)
• conflict — Conflict (409)
• csrf_failed — CSRF check failed (403)
• expired_token — Device request expired (400)
• forbidden — Forbidden (403)
• group_immutable — Group is immutable (409)
• group_name_exists — Group name already exists (409)
• group_not_empty — Group is not empty (409)
• invalid_credentials — Invalid credentials (401)
• invalid_group — Invalid group request (400)
• invalid_qualification_issuer — Invalid qualification issuer (401)
• invalid_request — Invalid request (400)
• invalid_service_credential — Invalid service credential (401)
• invalid_stream_ticket — Invalid stream ticket (401)
• invalid_token — Invalid token (401)
• invitation_existing_member — Invitation target is already a member (409)
• last_owner — Last owner (409)
• link_invalid — Link invalid (400)
• mail_delivery_unavailable — Mail delivery unavailable (503)
• membership_exists — Membership already exists (409)
• membership_removed — Membership removed (401)
• not_found — Not found (404)
• origin_not_allowed — Origin not allowed (403)
• qualification_authority_conflict — Qualification authority conflict (409)
• rate_limited — Rate limited (429)
• refresh_conflict — Refresh conflict (409)
• refresh_reuse — Refresh token reuse (401)
• registration_disabled — Registration disabled (403)
• slow_down — Polling too quickly (400)
• temporarily_unavailable — Temporarily unavailable (503)