You can build client libraries to interact with the Admin API or use the pre-built libraries for any of the available programming languages.
Building client libraries
Use both the Google API Discovery Service and the discovery document of the App Engine Admin API to build a client library. See Google API Discovery Service for information about using the discovery document of the Admin API to build the client library.
Client libraries for Google APIs
See Google API Client Libraries for information about the pre-built client libraries and all the available programming languages.
You can use any of the Google API Client Libraries to interact with the App Engine Admin API but the following languages have Admin API specific pages or instructions to help you get up and running with the client library: