Authentication and permission
401: missing or revoked credentials. 403: scope, organisation, entitlement, or resource restrictions.
Review the request
400: invalid recipient or content. 409: conflicting idempotency payload or a schedule already dispatched.
Retry carefully
429 includes Retry-After. Temporary provider failures can be retried using the same idempotency key. Never replace a key just because the response was lost.
Pilot access requires verified organisation configuration. Never expose a live API key in frontend code.