---
sidebar_position: 1
title: Installation
description: Install and configure the Firetell JavaScript / TypeScript Client SDK.
---
# Installation & Setup
The `@firetell/firetell-client-sdk` library allows you to build WebRTC-based voice and video calling features directly in web browsers and Node.js environments.
🎮 **Live Interactive Demo**: [https://developers.firetell.com/firetell-client-sdk/example/](https://developers.firetell.com/firetell-client-sdk/example/)
This SDK is a multi-format package supporting:
- **ESM** (ECMAScript Modules) for modern browsers and bundlers (Vite, Webpack, etc.)
- **CJS** (CommonJS) for Node.js backend integration
- **IIFE** (Immediately Invoked Function Expression) for direct inclusion via script tags (CDN)
---
## 1. Install via npm
If you are using a package manager (such as `npm`, `yarn`, or `pnpm`) in a bundled browser or Node.js environment, install the package:
```bash
npm install @firetell/firetell-client-sdk
```
---
## 2. Importing the SDK
### In Browser (ESM)
If you are using modern JavaScript/TypeScript bundlers (e.g. Vite, React, Angular, Vue, Next.js):
```typescript
import {
FiretellClient,
Call,
ECallState,
} from "@firetell/firetell-client-sdk";
// Initialize the client with the full domain name
const client = new FiretellClient("YOUR_AGENT_JWT", "yourcompany.firetell.app");
```
### In Node.js (CommonJS)
If you are running in a Node.js environment that uses CommonJS syntax:
```javascript
const { FiretellClient } = require("@firetell/firetell-client-sdk");
// Initialize the client with the full domain name
const client = new FiretellClient("YOUR_AGENT_JWT", "yourcompany.firetell.app");
```
> [!NOTE]
> **Node.js Environment Limitation:**
> Node.js does not support WebRTC features (making or receiving calls) due to the lack of native browser APIs like `RTCPeerConnection` or `getUserMedia`. In Node.js environments, the SDK is solely used for connecting to the gateway to receive real-time events via WebSocket connection.
---
## 3. Direct Script Tag (IIFE via CDN)
For simple HTML pages or legacy architectures where you do not use a build step or bundler, you can load the SDK directly from a CDN (such as jsDelivr or unpkg).
Add this script tag to the `` or `` of your HTML document:
```html
```
---
## ⚠️ Security Warning: Frontend Auth
> [!WARNING]
> **NEVER hardcode your Master API Key (`sk-...`) in frontend client-side code.**
>
> Exposing your master API Key gives anyone full access to provision phone numbers, configure billing, and read call records for your entire workspace.
To authenticate frontend clients safely:
1. Keep your master API Key securely on your **backend server**.
2. When an agent logs into your application, your backend should generate or retrieve a temporary **Agent JWT Token** representing that agent.
3. Pass the **Agent JWT Token** to your frontend browser client.
4. Use that JWT token to initialize the `FiretellClient` WebRTC SDK.
For a detailed walkthrough and code examples (Node.js, Python, PHP, ...) on how to generate the Agent JWT Token, refer to the [Client Authentication Guide](./authentication.md).
---
## System Requirements
To use the WebRTC calling features:
- **HTTPS or Localhost:** Web browsers require a secure origin (`https://` or `localhost`) to access microphone and camera devices (`navigator.mediaDevices.getUserMedia`).
- **Browser Support:** Modern web browsers with WebRTC support (Google Chrome, Mozilla Firefox, Apple Safari, Microsoft Edge).
- **Network Access:** Ensure WebSocket (`wss://`) traffic is allowed on your network to the Firetell signaling domains.
- **Node.js Environment Limitation:** Node.js environments do not support native WebRTC APIs, meaning making or receiving audio/video calls is not supported. Use Node.js environments strictly for subscribing to real-time events.