HTTP Status Codes
The Sentinel EMS REST API communicates errors through standard HTTP Status Codes. Every API call returns the following in response for success or failure:
>An HTTP status code: Provides the status of the HTTP request—that is, whether the request was successfully completed or not.
>A response body: Contains results of the HTTP request. In case of an error, the response body contains an error code and an error message.
The following table describes the status codes:
| Status Code | Description | 
|---|---|
| 200 OK | Indicates non-specific success. It must not be used to communicate errors in the response body. | 
| 201 Created | Indicates successful resource creation. | 
| 202 Accepted | Indicates successful start of an asynchronous action. | 
| 204 No Content | Indicates that the response body is intentionally empty. | 
| 400 Bad Request | Indicates non-specific failure. | 
| 401 Unauthorized | Indicates a problem with the client’s credentials. | 
| 403 Forbidden | Indicates no permission to access this resource. | 
| 404 Not Found | Used when a client’s URI cannot be mapped to a resource. | 
| 405 Method Not allowed | Used when the HTTP method is not supported. | 
| 429 Too Many Requests | Indicates incoming traffic exceeds the threshold. In case of this error, the application should wait for a specific amount of time before sending another request. A Retry-After header is included in the response indicating how long to wait before making a new request. This value is set to 60 seconds. | 
| 500 Internal Server Error | Indicates API malfunction. | 
| 503 Service Unavailable | Indicates that the server is unable to handle the request due to a temporary overloading or maintenance of the server. | 
