The NetScaler AppExpert APIs are available along with an SDK that documents the API usage, as well as the WSDLs for the API calls. Also available for OS versions 8.0 onwards, is the FilterWSDL tool, that lets users create a subset of the overall WSDLs, having only those API calls that the users intend to use within calling code. The filterWSDL helps create smaller WSDLs, so compilation of the WSDL can be fast.
Below are the list of available files for the various versions of the NetScaler Operating System.