The Legacy Client and Settings API typically returns an HTTP status code of 200 OK regardless of whether or not the API call completed successfully. That means that, in addition to looking at the status code, you must look at the API response in order to know whether the call succeeded. If the call fails, the API response will look similar to this:

{
  "stat": "error",
  "code": 100,
  "error_description": "missing arguments: flow",
  "error": "missing_argument",
  "request_id": "uyeem84bmqmnjuu4"
}

The following table provides a brief description of the properties found in a typical error message:

Error message propertyDescription
statStatus of the operation. Valid values are:

• OK
• Error
• Failed
codeStatus code associated with the error. Note that this code isn't a standard HTTP status code.
error_descriptionAdditional information about the error and why it might have occurred.
errorError type.
request_id16-character identifier assigned to each error response.

For information about the individual errors and error codes codes associated with this API, see Registration error codes.