Creating a client application for Indigo is somewhat similar to that of web services.  It uses a proxy class just like a call to a web service does.  A new tool, svcutil, can be used to generate a proxy by looking at the Indigo service in a DLL or it can look at the service directly and obtain a WSDL definition for it just like with web services.  I am guessing this process will be integrated into the IDE.
Here is an example of a client class:
using System.ServiceModel;
public class MyClassClient
    public static void Main()
          // instantiate the proxy class
          MyClassProxy myClass = new MyClassProxy();
          // call methods of proxy class
The above example would call the Indigo service and get the response of true and write it to the screen.

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