alexa-sdk

var handlers = {
    'LaunchRequest': function () {
        this.emit('SayHello');
    },
    'SayHello': function(){
        if (this.event.user.hasOwnProperty('accessToken')) {
            this.response.speak('Hello User');
            this.emit(':responseReady');
        }
        else {
            this.response.speak('You need to link your Vonage account, see the instructions in the Alexa App');
            this.emit(':responseReady');
        }
    },