> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ultravox.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Quickstart

> Get started with Ultravox in minutes - make your first AI voice call.

Get your first AI voice agent up and running in just a few minutes. This quickstart will walk you through making an automated phone call using Ultravox and Twilio.

> [!NOTE]
>
> **Don't use Twilio?**
>
> Ultravox Realtime enables you connect your voice AI agents via [telephony providers](https://docs.ultravox.ai/telephony/overview.md), [Websockets](https://docs.ultravox.ai/apps/websockets.md), [SIP trunks](https://docs.ultravox.ai/telephony/sip.md), or in [web/native apps](https://docs.ultravox.ai/apps/overview.md).

## Prerequisites

Before you begin, make sure you have:

**1. Ultravox account**

[Sign up here](https://app.ultravox.ai) if you haven't already

**2. API key**

Create one in the [Ultravox console](https://app.ultravox.ai/settings/)

**3. Twilio account**

with Account SID, Auth Token, and a phone number

**4. Node.js 20**

or higher installed

## Make Your First Outbound Call

Here's the core concept in 3 steps:

### 1. Create an Ultravox Call

```javascript theme={null}
const response = await fetch('https://api.ultravox.ai/api/calls', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'X-API-Key': 'YOUR_ULTRAVOX_API_KEY'
  },
  body: JSON.stringify({
    systemPrompt: "You are Steve, a friendly AI assistant calling to check in.",
    medium: { "twilio": {} },
    firstSpeakerSettings: { user: {} }
  })
});

const { joinUrl } = await response.json();
```

### 2. Make the Phone Call

```javascript theme={null}
const call = await twilioClient.calls.create({
  twiml: `<Response><Connect><Stream url="${joinUrl}"/></Connect></Response>`,
  to: '+1234567890',
  from: 'YOUR_TWILIO_NUMBER'
});
```

### 3. Your AI Agent Talks!

When the recipient answers, your AI agent starts the conversation.

***

**Want the complete working example?** Check out our [detailed outbound call example](https://docs.ultravox.ai/gettingstarted/examples/outbound-phone-call.md) with full setup instructions, error handling, and more.

## How It Works

This quickstart example:

1. **Creates an Ultravox call** configured for outbound phone calls
2. **Uses Twilio** to initiate the phone call to your target number
3. **Connects the call** to your AI agent using Ultravox's streaming API
4. **Starts the conversation** when the recipient answers

The AI agent follows the system prompt you provide and can have natural voice conversations with the person who answers.

## More Examples

Ready to explore more? Our examples repository includes complete implementations for:

* **[Incoming Phone Calls](https://docs.ultravox.ai/gettingstarted/examples/inbound-phone-call.md)** - Handle inbound calls with AI agents
* **[Outbound Phone Calls](https://docs.ultravox.ai/gettingstarted/examples/outbound-phone-call.md)** - Handle outbound calls with AI agents

[Explore All Examples →](https://github.com/ultravox-ai/ultravox-examples)

## What's Next?

### For Phone Integration:

* Learn about [Telephony Providers](https://docs.ultravox.ai/telephony/telephony-platforms.md) or [SIP](https://docs.ultravox.ai/telephony/sip.md).
* Check out the [Inbound Calls Example](https://docs.ultravox.ai/gettingstarted/examples/inbound-phone-call.md)
* Implement [Call Transfers](https://docs.ultravox.ai/telephony/call-transfers.md) to human agents

### For Web and Native Integrations:

* Try our [WebRTC SDK](https://docs.ultravox.ai/apps/sdks.md) for WebRTC-based voice chat
* Build custom voice interfaces for your applications

### Advanced Features:

* Create [Custom Voices](https://docs.ultravox.ai/voices/cloning.md) that match your brand
* Add [Custom Tools](https://docs.ultravox.ai/tools/custom/overview.md) to give your agents special capabilities
* Set up [Webhooks](https://docs.ultravox.ai/webhooks/overview.md) for real-time call notifications

## Need Help?

* **Discord**: Join our [community](https://discord.gg/62X253zeWB) for real-time support
* **Documentation**: Browse our complete [API reference](https://docs.ultravox.ai/api-reference)
* **Examples**: More working code in our [GitHub repository](https://github.com/ultravox-ai/ultravox-examples)

Start building powerful voice AI applications with Ultravox today!


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