***

id: 7a1538e3-fa4e-4377-8791-3b248bb6f768
title: Make and receive calls
sidebar-title: Get started
slug: /node/guides/get-started-with-voice
max-toc-depth: 3
x-custom:
author: danieleds
tags:

* 'language:nodejs'
* 'sdk:relayrealtime'
* 'product:voice'
  description: Learn how to get started with voice with the SignalWire Realtime SDK.
  keywords: >-
  SignalWire, Realtime SDK, Node.js, voice tutorial, getting started voice,
  first voice app
  sidebar\_custom\_props:
  platform: javascript

***

[buy-a-new-phone-number]: /docs/platform/phone-numbers

[log-in]: https://signalwire.com/signin

[realtime-sdk]: https://www.npmjs.com/package/@signalwire/realtime-api

This introductory guide will show you how to make and receive calls from your own Node.js application.

## Obtaining and configuring a number

[Log in][log-in] to your SignalWire Space. From the Phone Numbers section, you can [buy a new phone number][buy-a-new-phone-number]. You will need at least one number to make and receive calls. After you have acquired a number, open its settings by clicking on "Edit Settings". Scroll down until you reach "Voice and Fax Settings", as shown in the next figure, and configure it to:

* handle incoming calls using a RELAY application,
* forward the call to the "office" RELAY topic

<Frame caption="Voice configuration setting for handling incoming calls.">
  ![The Voice and Fax Settings pane.](https://files.buildwithfern.com/signalwire.docs.buildwithfern.com/docs/330ed4d26294f03cdd5ca7306c79f1aa711d9a03444c3d3c6eee31914bf6a448/assets/images/dashboard/relay/app_voice_handler.webp)
</Frame>

<Info title="Topic">
  In RELAY V4, a topic is a named scope that allows you to organize and categorize
  your resources. When you configure a phone number to handle calls with a RELAY
  application and specify a topic, all calls to that number will be delivered
  to RELAY clients listening on that topic.
</Info>

## Installation of the SDK

First, you need to obtain the [Realtime SDK][realtime-sdk] from npm. From your terminal you can run the following command to install it:

```shell npm2yarn
npm install --save @signalwire/realtime-api
```

Then, include the package in JavaScript as follows:

```js
import { SignalWire } from "@signalwire/realtime-api";
const voiceClient = client.voice;
```

### Making your first call

To make a call from Node.js you need to instantiate a Voice client, and then call one of its dialing methods.

```js
import { SignalWire } from "@signalwire/realtime-api";

const client = await SignalWire({
  project: "your-project-id",
  token: "your-api-token",
});

const voiceClient = client.voice;

try {
  const call = await voiceClient.dialPhone({
    from: "+1xxx", // Must be a number in your SignalWire Space
    to: "+1yyy",
    timeout: 30,
  });

  console.log("The call has been answered!", call.id);
} catch (e) {
  console.error(e);
}
```

You also need to specify a Project ID and API token: find these in the API section of your Space, as shown in the following figure. Make sure that your token has the "Voice" scope enabled.

<Frame caption="You can find your Project ID and Token from the API tab in your SignalWire Space. Make sure your token has the 'Voice' scope enabled.">
  ![the API tab, showing the Project ID, Space URL, and API Token.](https://files.buildwithfern.com/signalwire.docs.buildwithfern.com/docs/1bb2912f8cedf2a1a781e7100ecfaefcb7cec50da1089510286103cbb63c0d89/assets/images/dashboard/credentials/api-credentials.webp)
</Frame>

## Receiving incoming calls

Once a Client is initialized, you can listen for incoming calls on the selected topics (in our example, just "office"). For example:

```javascript
await voiceClient.listen({
  topics: ["office"],
  onCallReceived: async (call) => {
    console.log("Call received:", call.id, call.from, call.to);

    try {
      await call.answer();
      console.log("Inbound call answered");
    } catch (error) {
      console.error("Error answering inbound call", error);
    }
  },
});
```

We used the "office" topic when listening to the voice client's events.
The `topics` array is used only listen to the phone numbers that you have
put in that specific topic from the SignalWire dashboard.

Your event handler receives a call object, which you can use to answer the call, to access fields such as `call.from` and `call.to`, or to call additional methods (playing audio, prompting for input, transferring the call, etc.)

## Next steps

Congratulations! You can now make and receive calls with your Node.js application. You are now ready to explore the advanced guides in the Voice section from the left menu.