webhook_target_url_invalid
The target URL is outside the delivery policy: not absolute https (plain http is allowed only for localhost/127.0.0.1 outside production), carries userinfo, or - in production - is a private, link-local, loopback, or otherwise non-global IP literal. A registered target must not be a bridge into the deployment's own network.
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/webhook_target_url_invalid",
"title": "…",
"status": 422,
"detail": "…",
"instance": "/v1/…"
}