Edit in JSFiddle

// Define what a getTweets request looks like... url, dataType, etc
amplify.request.define( "getTweets", "ajax", {
    url: "http://twitter.com/status/user_timeline/{userName}.json?count={count}&callback=?",
    dataType: "json",
    type: "GET"
});

// You can redefine the request to mock out the response
amplify.request.define( "getTweets", function ( settings ) {
    settings.success([
        { text: "Test Tweet 1" },
        { text: "Test Tweet 2" },
        { text: "Test Tweet 3" },
        { text: "Test Tweet 4" },
        { text: "Test Tweet 5" }
    ]);    
});

// Subscribe to the "applciation.started" topic that is published later
amplify.subscribe( "application.started", function ( data ) {
    
    // Writes out the message that was passed in the Publish
    console.log( data.message );
    
    // Request "getTweets" passing in necessary data which
    // is used in URL substitution 
    amplify.request( "getTweets", 
        { userName: "AmplifyJS", count: "5" }, 
        function ( tweets ) {
        
            // Store the rich tweets array to persistent storage
            amplify.store( "tweets", tweets );
        
            // Retreive the tweets array from storage and write
            console.log( amplify.store( "tweets" ) );
        });
});

// Kick off the whole process by publishing message with data
amplify.publish( "application.started", {
    message: "Hello World!"
});