Transfer a call

A code snippet that shows how to transfer control of the current call to control by a new NCCO.

Example

Replace the following variables in the example code:

Key	Description
`UUID`	The UUID of the call to modify.
`action`	The action to use in updating the call. In this case `transfer`.
`NCCO_URL`	The URL of the NCCO to transfer control to. URLs must be array type.

Prerequisites

Use your existing application

Modifying an existing call requires that the UUID provided is a currently active call. To modify a call, you must use the same NEXMO_APPLICATION_ID and private key that were used to create the call.

Generate your JWT

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-a-call.sh:

Copy to Clipboard

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", "url": ["https://developer.nexmo.com/ncco/tts.json"]}}'

View full source

Run your code

Save this file to your machine and run it:

bash transfer-a-call.sh

Prerequisites

Use your existing application

Install dependencies

npm install nexmo

Initialize your dependencies

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

Copy to Clipboard

const Nexmo = require('nexmo');

const nexmo = new Nexmo({
  apiKey: NEXMO_API_KEY,
  apiSecret: NEXMO_API_SECRET,
  applicationId: NEXMO_APPLICATION_ID,
  privateKey: NEXMO_PRIVATE_KEY
}, { debug: true });

View full source

Write the code

Add the following to transfer-call.js:

Copy to Clipboard

const NCCO_URL = "https://developer.nexmo.com/ncco/tts.json";

nexmo.calls.update(UUID, {
  action: 'transfer',
  destination: {
    "type": "ncco",
    "url": [NCCO_URL]
  }
}, (err, res) => {
  if (err) {
    console.error(err);
  } else {
    console.log(res);
  }
});

View full source

Run your code

Save this file to your machine and run it:

node transfer-call.js

Prerequisites

Use your existing application

Install dependencies

Add the following to `build.gradle`:

compile 'com.nexmo:client:5.2.1'

Initialize your dependencies

Create a class named TransferCall and add the following code to the main method:

Copy to Clipboard

NexmoClient client = NexmoClient.builder()
        .applicationId(NEXMO_APPLICATION_ID)
        .privateKeyPath(NEXMO_PRIVATE_KEY_PATH)
        .build();

View full source

Write the code

Add the following to the main method of the TransferCall class:

Copy to Clipboard

client.getVoiceClient().transferCall(UUID, NCCO_URL);

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.nexmo.quickstart.voice with the package containing TransferCall:

gradle run -Pmain=com.nexmo.quickstart.voice.TransferCall

Prerequisites

Use your existing application

Install dependencies

Install-Package Nexmo.Csharp.Client

Import dependencies

Create a file named TransferCall.cs and add the following code:

Copy to Clipboard

using Nexmo.Api;
using Nexmo.Api.Request;
using Nexmo.Api.Voice;

View full source

Initialize your dependencies

Add the following to TransferCall.cs:

Copy to Clipboard

var credentials = Credentials.FromAppIdAndPrivateKeyPath(NEXMO_APPLICATION_ID, NEXMO_PRIVATE_KEY_PATH);
var client = new NexmoClient(credentials);

View full source

Write the code

Add the following to TransferCall.cs:

Copy to Clipboard

var callEditCommand = new CallEditCommand()
{
    Action = CallEditCommand.ActionType.transfer,
    Destination = new Destination()
    {
        Url = new[] { NCCO_URL }
    }
};

var response = client.VoiceClient.UpdateCall(UUID, callEditCommand);

View full source

Prerequisites

Use your existing application

Install dependencies

composer require nexmo/client

Initialize your dependencies

Create a file named index.php and add the following code:

Copy to Clipboard

$keypair = new \Nexmo\Client\Credentials\Keypair(
    file_get_contents(NEXMO_APPLICATION_PRIVATE_KEY_PATH),
    NEXMO_APPLICATION_ID
);

$client = new \Nexmo\Client($keypair);

View full source

Write the code

Add the following to index.php:

Copy to Clipboard

$client->calls[UUID]->put(new \Nexmo\Call\Transfer("https://developer.nexmo.com/ncco/transfer.json"));

View full source

Run your code

Save this file to your machine and run it:

php index.php

Prerequisites

Use your existing application

Install dependencies

pip install nexmo

Initialize your dependencies

Create a file named transfer-a-call.py and add the following code:

Copy to Clipboard

import nexmo
from pprint import pprint

client = nexmo.Client(
    application_id=APPLICATION_ID,
    private_key=APPLICATION_PRIVATE_KEY_PATH,
)

View full source

Write the code

Add the following to transfer-a-call.py:

Copy to Clipboard

dest = {"type": "ncco", "url": ["https://developer.nexmo.com/ncco/tts.json"]}
response = client.update_call(UUID, action="transfer", destination=dest)
pprint(response)

View full source

Run your code

Save this file to your machine and run it:

python3 transfer-a-call.py

Prerequisites

Use your existing application

Install dependencies

gem install nexmo

Initialize your dependencies

Create a file named transfer-a-call.rb and add the following code:

Copy to Clipboard


client = Nexmo::Client.new(
  application_id: NEXMO_APPLICATION_ID,
  private_key: File.read(NEXMO_APPLICATION_PRIVATE_KEY_PATH)

View full source

Write the code

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

Copy to Clipboard


ncco = {"type": "ncco", "url": ["https://developer.nexmo.com/ncco/transfer.json"]}

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

View full source

Run your code

Save this file to your machine and run it:

ruby transfer-a-call.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.