API Requests With a Body Must Send Content-Type: application/json
POST, PUT, PATCH and DELETE requests to /api/v1 that carry a body must now declare Content-Type: application/json (multipart/form-data for document upload). A body with no Content-Type, or another type such as application/x-www-form-urlencoded (the default of curl -d), is refused with HTTP 415 and the body {"error": "Unsupported content type", "code": "UNSUPPORTED_MEDIA_TYPE"}. Add -H "Content-Type: application/json" to such calls.