When an API call fails, the system returns an HTTP error code — e.g. 400, 401, or 500 — along with an <error_info> XML package describing the issue. This helps client applications diagnose and handle errors correctly.

XML structure

Standard API-level error

<error_info
  errorcode="111"                                  <!-- API error code -->
  message="Exception occurs when logging in 3scale."  <!-- Short error description -->
>
  <details>                                        <!-- Detailed diagnostic info -->
    CS_threescale.ApiException: application_not_found : application with id="46329c141" was not found
    at CS_threescale.Api.aux_authorize(Int32 key_type, String id, String key)
    ...
  </details>
</error_info>
Error with CAD server code
<error_info
  errorcode="120"                                  <!-- API error code -->
  message="Exception occurs inside CAD Server."    <!-- Short error description -->
  cadcode="0x1E"                                    <!-- CAD server error code -->
>
  <details>                                        <!-- Diagnostic details from CAD server -->
    Wilcom.Servers.CADEmbServer.CADException: Call to EmbServer_GetDesignInfo failed.
    Return code: ERROR_READ_FAULT
    ...
  </details>
</error_info>
Usage
The <error_info> XML can be returned by any API method when an error occurs. HTTP response will include:
A non-200 status code — 400, 401, 500, etc.
A corresponding <error_info> XML payload in the body. This element applies to all API methods.
The errorcode helps determine the category of failure.
The message is a summary for display or logging.
The <details> element may contain stack traces or diagnostics for troubleshooting.
If cadcode is present, refer to CAD server-specific errors for more precise diagnosis.
The information helps developers identify problems and take corrective actions, whether on the client side or when reporting issues to Wilcom support.
Always check both the HTTP status code and the contents of error_info to handle errors gracefully.
Elements
Element
Details
error_info
Root element for all error responses.
errorcode (integer)
Indicates the type of error encountered. See API Error Codes and CAD Error Codes below.
message (string)
A short, human-readable description of the error.
cadcode (hex string, optional)
CAD-specific error code. Only included when errorcode = 120.
<details> (optional)
Contains stack traces or debugging information helpful for development or support.

API error codes

CAD error codes

If the error is related to the CAD server, the cadcode attribute will be present to provide more specific insight.

Example:

<error_info
  errorcode="120"
  message="Exception occurs inside CAD Server."
  cadcode="0x1E"
>
  <details>
    Wilcom.Servers.CADEmbServer.CADException: Call to EmbServer_GetDesignInfo failed.
    Return code: ERROR_READ_FAULT
    ...
  </details>
</error_info>

Common CAD error codes: