checkout_unavailable
HTTP 503§9.10 Agreements
This deployment has no Stripe configuration, so the sandbox fee cannot be collected. Answers on POST /v1/onboarding/checkout. Signup still collects and stores answers - the portal says so rather than rendering a button that fails at Stripe.
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/checkout_unavailable",
"title": "…",
"status": 503,
"detail": "…",
"instance": "/v1/…"
}