There are different HTTP response code from the API:

• 200: the API call is processed successfully. The response data is a JSON object.
• 400: there are errors when processing the request
• 401: the access token is missing or invalid
• 403: the current user does not have sufficient privilege to call the current API
• 419: the current API is called with an incorrect method. For example, you send a POST request to an endpoint that only accepts GET requests.
• 422: the input data is not valid. The validation errors is returned in the body
• 5xx: there are errors in Resales Online servers
• 3xx: the Content-Type may be missing and the current request is not processed successfully