contact_list_in_use
DELETE /v1/contact-lists/{id} refused: a campaign still targets this list. A campaign's target is part of the record of what it dialed, so the list outlives the campaign; detail names the campaign. Delete the campaign first, or leave the list in place - its memberships cost nothing.
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/contact_list_in_use",
"title": "…",
"status": 409,
"detail": "…",
"instance": "/v1/…"
}