sinch-rtc/README.md

RTC JavaScript/Web SDK

# Sinch RTC SDK for JavaScript

The Sinch RTC SDK enables real-time **voice and video calling** directly in web applications. It provides a complete client-side solution for building in-app calling experiences in the browser.

## Features

- **App-to-App Calling** — High-quality voice and video calls between users in your application
- **App-to-PSTN Calling** — Call regular phone numbers directly from the browser
- **App-to-SIP Calling** — Connect to SIP endpoints for enterprise telephony integration
- **App-to-Conference Calling** — Join multi-party conference calls from the browser

## Prerequisites

1. [Register a Sinch account](https://dashboard.sinch.com/signup)
2. Create an application in the Dashboard to obtain an **Application Key** and **Application Secret**

## Installation

```bash
npm install sinch-rtc
```

## Quick Start

```javascript
import { Sinch } from "sinch-rtc";

const sinchClient = Sinch.getSinchClientBuilder()
  .applicationKey("YOUR_APP_KEY")
  .userId("YOUR_USER_ID")
  .build();

sinchClient.addListener({
  onClientStarted: (client) => {
    console.log("Sinch client started");
  },
  onClientFailed: (client, error) => {
    console.error("Sinch client failed", error);
  },
  onCredentialsRequired: (client, registrationCallback) => {
    // Fetch a signed JWT from your backend and pass it to the callback.
    // Never embed the Application Secret in client-side code.
    fetch("/api/sinch-jwt?userId=YOUR_USER_ID")
      .then((res) => res.json())
      .then(({ jwt }) => registrationCallback.register(jwt));
  },
});

sinchClient.start();
```

Please find more about how to generate JWT in our [documentation](https://developers.sinch.com/docs/in-app-calling/js/application-authentication).

## Making a Call

```javascript
const callClient = sinchClient.getCallClient();

callClient.addListener({
  onIncomingCall: (client, call) => {
    call.answer();
  },
});

const call = callClient.callUser("REMOTE_USER_ID");

call.addListener({
  onCallProgressing: (call) => {
    console.log("Ringing...");
  },
  onCallEstablished: (call) => {
    console.log("Call established");
  },
  onCallEnded: (call) => {
    console.log("Call ended");
  },
});
```

## Key Components

| Component       | Description                                                                                            |
| --------------- | ------------------------------------------------------------------------------------------------------ |
| **SinchClient** | Primary entry point — manages configuration, authentication, and feature controllers                   |
| **CallClient**  | Exposes APIs to place and receive calls, notifies about incoming call events                           |
| **Call**        | Represents an active call with methods for answering, declining, and hanging up                        |
| **Listeners**   | `SinchClientListener`, `CallClientListener`, and `CallListener` provide callbacks for state and events |

## Documentation

- [Getting Started Guide](https://developers.sinch.com/docs/in-app-calling/js/first-time-setup)
- [Full API Reference](https://download.sinch.com/js/latest/reference/index.html)
- [JavaScript Reference App](https://github.com/sinch/rtc-reference-applications/tree/master/javascript)
- [Try the Live Sample](https://in-app.sinch.com/javascript/samples/index.html)

## License

ISC