gRPC uses Protocol Buffer as IDL (Interface Definition Language) to define the structure of the API and the message formats, see https://grpc.io/docs/guides/concepts/.

You can generate client code for various programming languages on the basis of the interface definition. A complete list of currently supported languages can be found here: https://grpc.io/docs/languages/

Use the generated client code to connect to the server side of the API that is integrated in ibaHD-Server.