Transfer a call with inline NCCO

A code snippet that shows how to transfer control of the current call to control using inline NCCO.

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
`UUID`	The UUID of the call leg.
`TO_NUMBER`	The number you are calling. E.g. `447700900001`
`FROM_NUMBER`	The phone number you are calling from.

Prerequisites

Execute the following command at your terminal prompt to create the JWT for authentication:

export JWT=$(nexmo jwt:generate $PATH_TO_PRIVATE_KEY application_id=$NEXMO_APPLICATION_ID)

Write the code

Add the following to transfer-call-inline-ncco.sh:

curl -X PUT https://api.nexmo.com/v1/calls/$UUID \
  -H "Authorization: Bearer $JWT" \
  -H "Content-Type: application/json"\
  -d '{"action": "transfer",
      "destination": {"type": "ncco", "ncco": [{"action":"talk", "text":"This is a transfer action using an inline NCCO"}]}}'

View full source

Run your code

Save this file to your machine and run it:

bash transfer-call-inline-ncco.sh

Prerequisites

npm install @vonage/server-sdk

Create a file named transfer-call-with-ncco.js and add the following code:

const { Vonage } = require('@vonage/server-sdk');

const vonage = new Vonage({
  applicationId: VONAGE_APPLICATION_ID,
  privateKey: VONAGE_PRIVATE_KEY,
});

View full source

Write the code

Add the following to transfer-call-with-ncco.js:

vonage.voice.transferCallWithNCCO(UUID, {
  action: 'transfer',
  destination: {
    'type': 'ncco',
    'ncco': [
      {
        'action': 'talk',
        'text': 'This is a transfer action using an inline NCCO',
      },
    ],
  },
})
  .then(() => console.log('Call Transferred'))
  .catch((error) => console.error(error));

View full source

Run your code

Save this file to your machine and run it:

node transfer-call-with-ncco.js

Prerequisites

Add the following to build.gradle:

implementation 'com.vonage:server-sdk-kotlin:1.1.2'

Create a file named TransferCallWithNcco and add the following code to the main method:

val client = Vonage {
    applicationId(VONAGE_APPLICATION_ID)
    privateKeyPath(VONAGE_APPLICATION_PRIVATE_KEY_PATH)
}

View full source

Write the code

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

client.voice.call(CALL_UUID).transfer(
    talkAction("This is a transfer action using an inline NCCO.")
)

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 TransferCallWithNcco:

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

Prerequisites

Add the following to build.gradle:

implementation 'com.vonage:server-sdk:8.15.1'

Write the code

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

VonageClient client = VonageClient.builder()
        .applicationId(VONAGE_APPLICATION_ID)
        .privateKeyPath(VONAGE_PRIVATE_KEY_PATH)
        .build();

TalkAction talkAction = TalkAction.builder("This is a transfer action using an inline NCCO.").build();
client.getVoiceClient().transferCall(CALL_UUID, new Ncco(talkAction));

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 TransferCallNCCO:

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

Prerequisites

Install-Package Vonage

Write the code

Add the following to TransferCallNcco.cs:

var credentials = Credentials.FromAppIdAndPrivateKeyPath(vonageApplicationId, vonagePrivateKeyPath);
var client = new VonageClient(credentials);

var talkAction = new TalkAction() { Text = "This is a transfer action using an inline NCCO" };
var ncco = new Ncco(talkAction);
var callEditCommand = new CallEditCommand() 
{ 
    Action = CallEditCommand.ActionType.transfer, 
    Destination = new Destination() 
    { 
        Ncco = ncco
    } 
};

var response = await client.VoiceClient.UpdateCallAsync(uuid, callEditCommand);

View full source

Prerequisites

composer require vonage/client

Write the code

Add the following to index.php:

require_once __DIR__ . '/../../config.php';
require_once __DIR__ . '/../../vendor/autoload.php';

$keypair = new \Vonage\Client\Credentials\Keypair(file_get_contents(VONAGE_APPLICATION_PRIVATE_KEY_PATH), VONAGE_APPLICATION_ID);
$client = new \Vonage\Client($keypair);

if (count($argv) != 2) {
    error_log("You must supply a UUID of currently connected call to update");
    exit(1);
}

define('UUID', $argv[1]);

try {
    $call = $client->voice()->get(UUID);
    $ncco = new \Vonage\Voice\NCCO\NCCO();
    $ncco->addAction(new \Vonage\Voice\NCCO\Action\Talk('This call was transferred'));

    $client->voice()->transferCall(
        $call->getUuid(),
        new \Vonage\Voice\NCCO\Action\Transfer($ncco)
    );
} catch (\Vonage\Client\Exception\Request $e) {
    error_log("Client error: " . $e->getMessage());
    exit(1);
} catch (\Vonage\Client\Exception\Server $e) {
    error_log("Server error: " . $e->getMessage());
    exit(1);
}

View full source

Run your code

Save this file to your machine and run it:

php index.php

Prerequisites

pip install vonage

Write the code

Add the following to transfer-call-inline-ncco.py:

client = vonage.Client(
    application_id=os.getenv('VONAGE_APPLICATION_ID'),
    private_key=os.getenv("VONAGE_PRIVATE_KEY")
)

response = client.voice.create_call({
    "to": [{"type": "phone", "number": os.getenv('TO_NUMBER')}],
    "from": {"type": "phone", "number": os.getenv('FROM_NUMBER')},
    "ncco": [
        {
            "action": "talk",
            "text": "This is just a text whilst you tranfer to another NCCO"
        },
        # Play hold music until the call is transferred
        {
            "action": "stream",
            "streamUrl": [
                "https://example.com/hold-music.mp3"
            ],
            "loop": "0"
        }
    ]
})

# Give the recipient time to answer 
time.sleep(5)

response = client.voice.update_call(
    response["uuid"], {
        "action": "transfer",
        "destination": {
            "type": "ncco",
            "ncco": [{"action": "talk", "text": "hello world"}]
        }
    }
)


print(response)

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Run your code

Save this file to your machine and run it:

python transfer-call-inline-ncco.py

Prerequisites

gem install vonage

Write the code

Add the following to transfer-a-call-ncco.rb:

client = Vonage::Client.new(
  application_id: VONAGE_APPLICATION_ID,
  private_key: File.read(VONAGE_APPLICATION_PRIVATE_KEY_PATH)
)

ncco = {
  "type": 'ncco',
  "ncco": [
    "action": 'talk',
    "text": 'This is a transfer action using an inline NCCO'
  ]
}

response = client.voice.transfer(UUID, destination: ncco)

puts response.inspect

View full source

Run your code

Save this file to your machine and run it:

ruby transfer-a-call-ncco.rb

Try it out

You will need to:

Set up a call and obtain the call UUID. You could use the 'connect an inbound call' code snippet to do this.
Run the example code to transfer the call.
Control will be transferred to a new NCCO, and you will hear a text-to-speech message to confirm this.

Transfer a call with inline NCCO

Prerequisites

Create an Application

Rent a Number

Link a Number

Example

Prerequisites

Write the code

Run your code

Prerequisites

Write the code

Run your code

Prerequisites

Write the code

Run your code

Prerequisites

Write the code

Run your code

Prerequisites

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Prerequisites

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Run your code

Prerequisites

Write the code

Run your code

Prerequisites

Write the code

Run your code

Try it out

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