Create the answer webhook

When your Vonage number receives a call, the Vonage API platform makes a request to your answer URL webhook endpoint. The webhook must return an NCCO, which is a JSON array of objects. Each object in the array consists of an action that determines how the call should progress.

In this step you will build that webhook. Add the following handler for the /webhooks/answer route:

app.get('/webhooks/answer', (req, res) => {
	res.json(mainMenu(req));
});

Beneath it, write the code for the mainMenu function, which creates and returns an NCCO. We have wrapped the code that generates the NCCO in a function so that we can call it from elsewhere in our application, and not only from our answer webhook:

function mainMenu (req) {
	return [
		{
			action: 'talk',
			bargeIn: true,
			text:
				'Welcome. Press 1 to hear the current date or 2 to play audio. Press any other key to hear these options again.',
		},
		{
			action: 'input',
      type: [ 'dtmf' ],
      dtmf: {
        maxDigits: 1,  
      },
			eventUrl: [ `${req.protocol}://${req.get('host')}/webhooks/dtmf` ],
		},
	];
}

The NCCO this function generates consists of two actions:

• talk reads the menu options to the caller using text-to-speech. The bargeIn property is set to true, which enables a user to interrupt the reading of the message
• input waits for the user to press a key on the phone's keypad and then makes a request to another webhook (defined in eventUrl) with the details of the key they pressed. You will create this webhook in the next step.