Connect an inbound call

In this code snippet you see how to connect an inbound call to another person by making an outbound call.

Prerequisites

Create an Application

You can install the CLI with the following command:

npm install --location=global @vonage/cli

Before you can start working with your apps, you need to register your configuration: API Key and Secret. You can find them via the Dashboard, in API Settings. Once set, initialize your account using the following command:

vonage config:set --apiKey=XXXXXX --apiSecret=XXXXXX

As soon as the CLI is both installed and configured, use it to create a Vonage application using the following command:

vonage apps:create

The command starts an interactive prompt to ask for the application name, and the capabilities you want to enable - make sure to enable Voice.

When finished, it creates the vonage_app.json file in the current directory containing the Application ID, Application name and private key. It also creates a second file with the private key name app_name.key.

Go to the Application's page on the Dashboard, and define a Name for your Application.

Make sure to click on the Generate public and private key button, and keep the file private.key around.

Then, enable the Voice capability. For the moment, leave everything by default.

An example of enabling Voice capabilities

Finally, click Save at the bottom of the page.

Rent a Number

You can rent a number using the Vonage CLI. The following command purchases an available number in the United States:

vonage numbers:search USvonage numbers:buy 15555555555 US

Specify an alternative two-character country code to purchase a number in another country.

Link a Number

Now that you have both an application and a number, you need to link them together.

Replace YOUR_VONAGE_NUMBER with the number you bought and APPLICATION_ID with your application id, then run the following command:

vonage apps:link APPLICATION_ID --number=YOUR_VONAGE_NUMBER

Example

Replace the following variables in the example code:

Key	Description
`VONAGE_NUMBER`	Your Vonage Number. E.g. `447700900000`
`YOUR_SECOND_NUMBER`	The number you are connecting to. E.g. `447700900002`

Prerequisites

npm install express

Write the code

Add the following to connect-an-inbound-call.js:

const Express = require('express');

const app = new Express();

const onInboundCall = (request, response) => {
  const ncco = [
    {
      action: 'connect',
      from: VONAGE_NUMBER,
      endpoint: [
        {
          type: 'phone',
          number: YOUR_SECOND_NUMBER,
        },
      ],
    },
  ];

  response.json(ncco);
};

app.get('/webhooks/answer', onInboundCall);

app.listen(3000);

View full source

Run your code

Save this file to your machine and run it:

node connect-an-inbound-call.js

Prerequisites

Add the following to build.gradle:

implementation 'com.vonage:server-sdk-kotlin:1.1.2'
implementation 'io.ktor:ktor-server-netty'
implementation 'io.ktor:ktor-serialization-jackson'

Write the code

Add the following to the main method of the ConnectInboundCall file:

embeddedServer(Netty, port = 8000) {
    routing {
        route("/webhooks/answer") {
            handle {
                call.response.header("Content-Type", "application/json")
                call.respond(
                    Ncco(
                        connectToPstn(YOUR_SECOND_NUMBER) {
                            from(VONAGE_NUMBER)
                        }
                    ).toJson()
                )
            }
        }
    }
}.start(wait = true)

View full source

Run your code

We can use the application plugin for Gradle to simplify the running of our application. Update your build.gradle with the following:

apply plugin: 'application'
mainClassName = project.hasProperty('main') ? project.getProperty('main') : ''

Run the following gradle command to execute your application, replacing com.vonage.quickstart.kt.voice with the package containing ConnectInboundCall:

gradle run -Pmain=com.vonage.quickstart.kt.voice.ConnectInboundCall

Prerequisites

Add the following to build.gradle:

implementation 'com.vonage:server-sdk:8.15.1'
implementation 'com.sparkjava:spark-core:2.9.4'

Write the code

Add the following to the main method of the ConnectInboundCall file:

/*
 * Route to answer incoming calls with an NCCO response.
 */
Route answerRoute = (req, res) -> {
    ConnectAction connect = ConnectAction.builder()
            .endpoint(PhoneEndpoint.builder(YOUR_SECOND_NUMBER).build())
            .from(VONAGE_NUMBER)
            .build();

    res.type("application/json");

    return new Ncco(connect).toJson();
};

Spark.port(3000);
Spark.get("/webhooks/answer", answerRoute);
Spark.post("/webhooks/answer", answerRoute);

View full source

Run your code

We can use the application plugin for Gradle to simplify the running of our application. Update your build.gradle with the following:

apply plugin: 'application'
mainClassName = project.hasProperty('main') ? project.getProperty('main') : ''

Run the following gradle command to execute your application, replacing com.vonage.quickstart.voice with the package containing ConnectInboundCall:

gradle run -Pmain=com.vonage.quickstart.voice.ConnectInboundCall

Prerequisites

Install-Package Vonage

Write the code

Add the following to ConnectInboundCallController.cs:

[Route("webhooks/answer")]
public string Answer()
{
    var yourSecondNumber = Environment.GetEnvironmentVariable("YOUR_SECOND_NUMBER") ?? "YOUR_SECOND_NUMBER";
    var vonageNumber = Environment.GetEnvironmentVariable("VONAGE_NUMBER") ?? "VONAGE_NUMBER";

    var talkAction = new TalkAction()
    {
        Text = "Thank you for calling",
        Language = "en-gb",
        Style = 2
    };

    var secondNumberEndpoint = new PhoneEndpoint() { Number=yourSecondNumber};            
    var connectAction = new ConnectAction() { From=vonageNumber, Endpoint= new[] { secondNumberEndpoint } };
    
    var ncco = new Ncco(talkAction,connectAction);
    return ncco.ToString();
}

View full source

Prerequisites

composer require slim/slim:^3.8 vonage/client

Write the code

Add the following to index.php:

require 'vendor/autoload.php';

$dotenv = Dotenv::createImmutable(__DIR__);
$dotenv->load();

define('YOUR_SECOND_NUMBER', getenv('YOUR_SECOND_NUMBER'));
define('VONAGE_NUMBER', getenv('VONAGE_NUMBER'));

$app = new \Slim\App();

$app->get('/webhooks/answer', function (Request $request, Response $response) {
    $numberToConnect = new \Vonage\Voice\Endpoint\Phone(YOUR_SECOND_NUMBER);

    $action = new \Vonage\Voice\NCCO\Action\Connect($numberToConnect);
    $action->setFrom(VONAGE_NUMBER);

    $ncco = new \Vonage\Voice\NCCO\NCCO();
    $ncco->addAction($action);

    return new JsonResponse($ncco->toArray());
});

$app->run();

View full source

Run your code

Save this file to your machine and run it:

php -S localhost:3000 -t .

Prerequisites

pip install 'flask>=1.0'

Write the code

Add the following to connect-an-inbound-call.py:

#!/usr/bin/env python3
from flask import Flask, jsonify

app = Flask(__name__)


@app.route("/webhooks/answer")
def answer_call():
    ncco = [
        {
            "action": "connect",
            "from": "VONAGE_NUMBER",
            "endpoint": [{
                "type": 'phone',
                "number": "YOUR_SECOND_NUMBER"
            }]
        }
    ]
    return jsonify(ncco)

View full source

Run your code

Save this file to your machine and run it:

python connect-an-inbound-call.py

Prerequisites

gem install sinatra sinatra-contrib

Write the code

Add the following to connect_an_inbound_call.rb:

require 'sinatra'
require 'sinatra/multi_route'
require 'json'

before do
  content_type :json
end

route :get, :post, '/webhooks/answer' do
  [{
    action: 'connect',
    endpoint: [{
      type: 'phone',
      number: YOUR_SECOND_NUMBER
    }]
  }].to_json
end

set :port, 3000

View full source

Run your code

Save this file to your machine and run it:

ruby connect_an_inbound_call.rb

Try it out

You'll need to expose your server to the open internet. During development you can use a tool like Ngrok to do that.

When you call your Vonage Number you will automatically be connected to the number you specified in place of YOUR_SECOND_NUMBER.

## Further Reading

Interactive Voice Response (IVR) - Build an automated phone system for users to input information with the keypad and hear a spoken response.
Voice Bot with Google Dialogflow - This guide will help you to start with an example Dialogflow bot and interact with it from phone calls using provided sample reference codes using Vonage Voice API.
Masked Calling - Enable users to call each other, keeping their real numbers private.
Conference Calling - This guide explains the two concepts Vonage associates with a call, a leg and a conversation.
Call Tracking - Keep track of which campaigns are working well by using different numbers for each one and tracking the incoming calls. This guide shows you how to handle incoming calls, connect them to another number, and track the phone numbers that called each of your Vonage numbers.