ServiceAnnotationFlow.java

End result:

You will get to make a service request like this: 
        mAppDelegate.execute(UserActions.loginAction().facebookToken(token).username(username).build());
        
And have these classes generated for you:
        UserActions,
        LoginActionsFactory,
        LoginActivityEventListener

Usage: 

Tag the action: 

@AggregatedAnnotation( //Generates UserActions class
        baseClass = ActionKey.class,
        valueType = BaseUserAction.class,
        group = ActionKey.User) //"UserActions"
@EventProducer(events = {LoginActionResult.class}) //Tags this producer with the events they post.  
@FactoryWithVariables( //Generates the Factory that makes the request. 
        baseClass = ActionRequestBuilder.class,
        variables = {
                @FactoryVariable(name = LoginAction.EXTRA_FACEBOOK_TOKEN, kind = String.class)
        })
public class LoginAction extends BaseUserAction {
  //Processing...
}

Tag the requester/listener: 

@EventListener(producers = { //Creates LoginActivityEventListener that implements a list of events from the list of producers.
        LoginAction.class
})
public class LoginActivity extends BaseActivity {
    final LoginActivityEventListener mListener = new LoginActivityEventListener() {

        @Override
        public void onEventMainThread(LoginActionResult event) {

        }
    };
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        addListener(mListener);
    }
}