sso_signing_unavailable
POST /auth/sso/start: the company requires signed SAML AuthnRequests and its SP signing key could not be read from the vault. The request is never sent unsigned. Try again, or sign in another way.
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/sso_signing_unavailable",
"title": "…",
"status": 503,
"detail": "…",
"instance": "/v1/…"
}