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.
url The URL of the NCCO to transfer control to. URLs must be array type (for Python library).
  • cURL
  • Node.js
  • Java
  • .NET
  • PHP
  • Python
  • Ruby

    • 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

    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.

    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:

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    nexmo.calls.update(CALL_UUID, {action: 'transfer', destination: {"type": "ncco", "url": ["https://developer.nexmo.com/ncco/tts.json"]}}, (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

    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.

    Install dependencies

    Add the following to `build.gradle`:

    compile 'com.nexmo:client:5.1.0'
    Initialize your dependencies

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

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    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:

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    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

    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.

    Install dependencies

    Install-Package Nexmo.Csharp.Client
    Initialize your dependencies

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

    Copy to Clipboard 
    var client = new Client(creds: new Nexmo.Api.Request.Credentials
{
    ApiKey = "NEXMO_API_KEY",
    ApiSecret = "NEXMO_API_SECRET",
    ApplicationId = "NEXMO_APPLICATION_ID",
    ApplicationKey = "NEXMO_APPLICATION_PRIVATE_KEY"
});

    View full source

    Write the code

    Add the following to VoiceSender.cs:

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    var result = client.Call.Edit(UUID, new Call.CallEditCommand
{
    Action = "transfer",
    Destination = new Call.Destination
    {
        Type = "ncco",
        Url = new[] { "https://developer.nexmo.com/ncco/transfer.json" }
    }
});

    View full source

    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.

    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:

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    $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

    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.

    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:

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    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

    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.

    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:

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

response = client.calls.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.rb

    Try it out

    You will need to:

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