> This page is for Compatibility API.

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# Compatibility API

The SignalWire Compatibility API provides a seamless migration path from Twilio\* to SignalWire. If you've built applications using Twilio's TwiML, REST API, or helper libraries, you can transition to SignalWire with minimal code changes while gaining access to SignalWire's powerful infrastructure and competitive pricing.

## Quick start migration

Migrating from Twilio to SignalWire typically requires just three changes:

#### Update your credentials

Replace your Twilio Account SID and Auth Token with your SignalWire Project ID and API Token from your [SignalWire Dashboard](https://signalwire.com/signin).

#### Change the API endpoint

If using the Twilio REST API or SDK, update the base URL from `api.twilio.com` to `your-space.signalwire.com`, where `your-space` is your SignalWire Space name. This is not required if using the SignalWire Compatibility SDK.

#### Update webhook URLs

Point your phone number webhooks to your SignalWire Space. Your existing TwiML/cXML response handlers work without modification.

## What's included

The Compatibility API provides three main components:

#### [cXML](/docs/compatibility-api/cxml)

SignalWire's XML-based language for controlling calls, messages, and faxes — directly compatible with Twilio's TwiML.

#### [Client SDKs](/docs/compatibility-api/rest/client-sdks)

Helper libraries for generating cXML and making REST API calls in your preferred language.

#### [REST API](/docs/compatibility-api/rest)

RESTful endpoints for managing calls, messages, phone numbers, recordings, and more.

## Migrating from Twilio

You can easily migrate from Twilio with minimal changes. Replace the Twilio client with the SignalWire client and update the `from` number to a valid SignalWire number.

> **Make sure to change the 'From' number!**
>
> When migrating to SignalWire, make sure to replace the `from` numbers with a valid SignalWire number.

```javascript {2-3}
// Replace these lines:
const twilio = require('twilio')
const response = new twilio.twiml.VoiceResponse()
```

```javascript {2-3}
// With:
const { RestClient } = require('@signalwire/compatibility-api')
const response = new RestClient.LaML.VoiceResponse()
```

**`Node.js`**

```javascript title="Node.js"
// Now use response like you did before!
response.say('Hey, welcome to SignalWire!')
```

## Supported features

The Compatibility API supports the full range of Twilio-compatible features:

| Category          | Features                                                                               |
| ----------------- | -------------------------------------------------------------------------------------- |
| **Voice**         | Inbound/outbound calls, call control, conferencing, queues, recordings, transcriptions |
| **Messaging**     | SMS, MMS, status callbacks                                                             |
| **Fax**           | Send and receive faxes                                                                 |
| **Phone Numbers** | Purchase, configure, and manage phone numbers                                          |
| **Applications**  | Manage voice and messaging application configurations                                  |

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\*Twilio and TwiML are trademarks of Twilio, Inc. SignalWire, Inc. and its products are not affiliated with or endorsed by Twilio, Inc.