admin_auth_unavailable
The staff plane is not configured in this deployment, so /admin cannot authenticate anyone. Since ADR-0017 the missing dependency is the admin database engine - staff identity needs no identity provider, because a staff session IS a first-party session. Was 501 until 2026-08-09 (adr/0015-bespoke-staff-console.md decision 3.5): 501 claims the server does not implement the surface, which became false when the console shipped and was always misleading where only the configuration was missing. It is a missing dependency, so it joins the 503 family with runtime_plane_unavailable and internal_auth_unavailable.
Problem shape
Every non-2xx response is an RFC 9457 application/problem+json body. The type URI below is stable and machine-matchable, so branch on the final path segment (the code) and treat the status as redundant confirmation. See the error-handling guide.
{
"type": "https://docs.vocapable.com/errors/admin_auth_unavailable",
"title": "…",
"status": 503,
"detail": "…",
"instance": "/v1/…"
}