Modify Calls In Progress

// Download the Node helper library from twilio.com/docs/node/install
// These vars are your accountSid and authToken from twilio.com/user/account
var accountSid = 'ACXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX';
var authToken = "your_auth_token";
var client = require('twilio')(accountSid, authToken);

client.calls("CAe1644a7eed5088b159577c5802d8be38").update({
    url: "http://demo.twilio.com/docs/voice.xml",
    method: "POST"
}, function(err, call) {
    console.log(call.to);
});

// Download the Node helper library from twilio.com/docs/node/install
// These identifiers are your accountSid and authToken from
// https://www.twilio.com/console
const accountSid = 'ACXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX';
const authToken = 'your_auth_token';
const client = require('twilio')(accountSid, authToken);

client.calls('CAe1644a7eed5088b159577c5802d8be38')
  .update({
    url: 'http://demo.twilio.com/docs/voice.xml',
    method: 'POST',
  })
  .then((call) => console.log(call.to));

// Download the twilio-csharp library from twilio.com/docs/csharp/install
using System;
using Twilio;
class Example 
{
  static void Main(string[] args) 
  {
    // Find your Account Sid and Auth Token at twilio.com/user/account
    string AccountSid = "ACXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";
    string AuthToken = "your_auth_token";
    var twilio = new TwilioRestClient(AccountSid, AuthToken);

    twilio.RedirectCall("CAe1644a7eed5088b159577c5802d8be38", 
        "http://demo.twilio.com/docs/voice.xml", "POST");
  }
}

<?php
// Get the PHP helper library from https://twilio.com/docs/libraries/php
require_once('/path/to/twilio-php/Services/Twilio.php'); // Loads the library

// Your Account Sid and Auth Token from twilio.com/user/account
$sid = "ACXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"; 
$token = "your_auth_token"; 
$client = new Services_Twilio($sid, $token);

// Get an object from its sid. If you do not have a sid,
// check out the list resource examples on this page
$call = $client->account->calls->get("CAe1644a7eed5088b159577c5802d8be38");
$call->update(array(
        "Url" => "http://demo.twilio.com/docs/voice.xml",
    "Method" => "POST"
    ));
echo $call->to;

# Get twilio-ruby from twilio.com/docs/ruby/install
require 'rubygems' # This line not needed for ruby > 1.8
require 'twilio-ruby'

# Get your Account Sid and Auth Token from twilio.com/user/account
account_sid = 'ACXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'
auth_token = 'your_auth_token'
@client = Twilio::REST::Client.new account_sid, auth_token

# Get an object from its sid. If you do not have a sid,
# check out the list resource examples on this page
@call = @client.account.calls.get('CAe1644a7eed5088b159577c5802d8be38')
@call.update(url: 'http://demo.twilio.com/docs/voice.xml',
             method: 'POST')
puts @call.to

// Download the twilio-csharp library from twilio.com/docs/libraries/csharp
using System;
using Twilio;
using Twilio.Http;
using Twilio.Rest.Api.V2010.Account;

class Example
{
    static void Main(string[] args)
    {
        // Find your Account Sid and Auth Token at twilio.com/console
        const string accountSid = "ACXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";
        const string authToken = "your_auth_token";
        TwilioClient.Init(accountSid, authToken);

        CallResource.Update(
            "CAe1644a7eed5088b159577c5802d8be38",
            url: new Uri("http://demo.twilio.com/docs/voice.xml"),
            method: HttpMethod.Post);
    }
}

<?php
// Get the PHP helper library from https://twilio.com/docs/libraries/php
require_once '/path/to/vendor/autoload.php'; // Loads the library
use Twilio\Rest\Client;

// Your Account Sid and Auth Token from twilio.com/user/account
$sid = "ACXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";
$token = "your_auth_token";
$client = new Client($sid, $token);

// Get an object from its sid. If you do not have a sid,
// check out the list resource examples on this page
$call = $client
    ->calls("CAe1644a7eed5088b159577c5802d8be38")
    ->update(
        array(
            "url" => "http://demo.twilio.com/docs/voice.xml",
            "method" => "POST"
        )
    );

echo $call->to;

# Download the Python helper library from twilio.com/docs/python/install
from twilio.rest import TwilioRestClient

# Your Account Sid and Auth Token from twilio.com/user/account
account_sid = "ACXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
auth_token  = "your_auth_token"
client = TwilioRestClient(account_sid, auth_token)

call = client.calls.update(
    "CAe1644a7eed5088b159577c5802d8be38",
    url="http://demo.twilio.com/docs/voice.xml",
    method="POST")
print(call.to)

# Get twilio-ruby from twilio.com/docs/ruby/install
require 'twilio-ruby'

# Get your Account SID and Auth Token from twilio.com/console
account_sid = 'ACXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'
auth_token = 'your_auth_token'

# Initialize Twilio Client
@client = Twilio::REST::Client.new(account_sid, auth_token)

@call = @client.api.calls('CAe1644a7eed5088b159577c5802d8be38')

@call.update(
  url: 'http://demo.twilio.com/docs/voice.xml',
  method: 'POST'
)

puts @call.to

// Install the Java helper library from twilio.com/docs/java/install
import com.twilio.sdk.TwilioRestClient;
import com.twilio.sdk.TwilioRestException;
import com.twilio.sdk.resource.instance.Call;
import com.twilio.sdk.resource.list.CallList;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;

public class Example { 

  // Find your Account Sid and Token at twilio.com/user/account
  public static final String ACCOUNT_SID = "ACXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";
  public static final String AUTH_TOKEN = "your_auth_token";

  public static void main(String[] args) throws TwilioRestException {
    TwilioRestClient client = new TwilioRestClient(ACCOUNT_SID, AUTH_TOKEN);

    // Get an object from its sid. If you do not have a sid,
    // check out the list resource examples on this page
    Call call = client.getAccount().getCall("CAe1644a7eed5088b159577c5802d8be38");
    // Build a filter for the CallList
    List<NameValuePair> params = new ArrayList<NameValuePair>();
    params.add(new BasicNameValuePair("Url", "http://demo.twilio.com/docs/voice.xml"));
    params.add(new BasicNameValuePair("Method", "POST"));
    call.update(params);
    
  }
}

# Download the Python helper library from twilio.com/docs/python/install
from twilio.rest import Client

# Your Account Sid and Auth Token from twilio.com/user/account
account_sid = "ACXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
auth_token = "your_auth_token"
client = Client(account_sid, auth_token)

call = client.calls("CAe1644a7eed5088b159577c5802d8be38") \
             .update(url="http://demo.twilio.com/docs/voice.xml",
                     method="POST")

print(call.to)

// Install the Java helper library from twilio.com/docs/java/install
import com.twilio.Twilio;
import com.twilio.http.HttpMethod;
import com.twilio.rest.api.v2010.account.Call;

public class Example {
  // Find your Account Sid and Token at twilio.com/user/account
  public static final String ACCOUNT_SID = "ACXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX";
  public static final String AUTH_TOKEN = "your_auth_token";

  public static void main(String[] args) {
    Twilio.init(ACCOUNT_SID, AUTH_TOKEN);

    // Get an object from its sid. If you do not have a sid,
    // check out the list resource examples on this page
    Call call = Call.updater("CAe1644a7eed5088b159577c5802d8be38")
        .setUrl("http://demo.twilio.com/docs/voice.xml").setMethod(HttpMethod.POST).update();

    System.out.println(call.getDateUpdated());
  }
}

$ curl -XPOST https://api.twilio.com/2010-04-01/Accounts/ACXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX/Calls/CAe1644a7eed5088b159577c5802d8be38 \
    -d "Url=http://demo.twilio.com/docs/voice.xml" \
    -d "Method=POST" \
    -u 'ACXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX:your_auth_token'

$ curl -XPOST https://api.twilio.com/2010-04-01/Accounts/ACXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX/Calls/CAe1644a7eed5088b159577c5802d8be38.json \
    -d "Url=http://demo.twilio.com/docs/voice.xml" \
    -d "Method=POST" \
    -u 'ACXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX:your_auth_token'