Add a Call Whisper using Node and the Vonage Voice API

This app used the Vonage Voice APIs to demonstrate how add a "whisper" (a spoken announcement to only one caller before connecting) to a call using the onAnswer feature.

Prerequisites

You will need:

• A free Vonage account
• The Vonage CLI installed
• A way to run a local server on a public port, for example Ngrok.

Installation

git clone https://github.com/Vonage-Community/sample-voice-nodejs-call-whisper
cd node-call-whispher
npm install

Setup

Buy Numbers & Create Application

To run this application we need to buy 2 numbers, set up an application, and tie the numbers to this application.

1. create an application

voange apps create "Whisper System"

2. Add voice capabilities to the application

vonage apps capabilities update voice 00000000-0000-0000-0000-000000000000 --voice-inbound-url http://your.domain/answer_inbound --voice-event-url http://your.domain/event

3. Buy 2 numbers (run this command for each number):

vonage numbers buy US 16127779311

4. Link the numbers to the application ID (once for each number):

vonage apps numbers link 00000000-0000-0000-0000-000000000000 16127779311

Run Server

The next step is to set up all of our variables in a .env file. You can start off by copying the example file.

mv .env.example .env

Fill in the values in .env as appropriate, where INBOUND_NUMBER_1 and INBOUND_NUMBER_2 are the numbers you just purchased, CALL_CENTER_NUMBER is the number you want them to direct to. Finally, DOMAIN is the public domain or hostname your server is available on.

With this in place you can start the server.

npm start

The application should be available on http://localhost:5000. For this to work full though, make sure to expose your server on a public domain (e.g. your.domain in the example above) using a tool like Ngrok.

Using the App

To use the app you need two phones, or a phone and something like WhatsApp to make the first call.

With your server running, call either of the 2 numbers you purchased. Vonage will then make a call to http://your.domain/answer_inbound which puts the inbound call on hold. A call is then made to the CALL_CENTER_NUMBER(your other phone) where a message is played regarding the nature of the call before both parties are connected to the same conference.

More Information

For a more detailed writeup, see the tutorial on the Vonage Developer Portal.