Appendix C: Error codes and description
REST Messages sent to ServiceNow instance return the below mentioned HTTP response codes.
| Status code | Message | Details |
|---|---|---|
| 200 | Success | Success with response body. |
| 201 | Created | Success with response body. |
| 204 | Success | Success with no response body. |
| 400 | Bad Request | The request URI does not match the APIs in the system, or the operation failed for unknown reasons. Invalid headers can also cause this error. |
| 401 | Unauthorized | The user is not authorized to use the API. |
| 403 | Forbidden | The requested operation is not permitted for the user. This error can also be caused by ACL failures, or business rule or data policy constraints. |
| 404 | Not found | The requested resource was not found. This can be caused by an ACL constraint or if the resource does not exist. |
| 405 | Method not allowed | The HTTP action is not allowed for the requested REST API, or it is not supported by any API. |
| 406 | Not acceptable | The endpoint does not support the response format specified in the request Accept header. |
| 415 | Unsupported media type | The endpoint does not support the format of the request body. |