# Quickstart (/en/realtime-media/broadcast-streaming/quickstart/unity)

> For AI agents: see the complete documentation index at [llms.txt](/llms.txt).

This page provides a step-by-step guide on how to create a basic Broadcast Streaming app using the Agora Video SDK.

## Understand the tech

To start a Broadcast Streaming session, implement the following steps in your app:

* **Initialize the Agora Engine**: Before calling other APIs, create and initialize an Agora Engine instance.

* **Join a channel**: Call methods to create and join a channel.

  * **Join as a host**: A live streaming event has one or more hosts. A host publishes audio and video to the channel. Hosts can also subscribe to streams from other hosts.

  * **Join as audience**: Audience members can only subscribe to streams published by hosts.

* **Send and receive audio and video**: Hosts publish streams to the channel. Audience members subscribe to audio and video streams published by hosts.

![Streaming workflow](https://assets-docs.agora.io/images/video-sdk/get-started-ils-bs.svg)

## Prerequisites

* [Unity Hub](https://unity.com/download) and [Unity Editor](https://unity.com/releases/editor/archive) 2018.4.0 or higher

* A suitable operating system and compiler for your development platform:

  | Development platform | Operating system version | Compiler version                      |
  | :------------------- | :----------------------- | :------------------------------------ |
  | Android              | Android 4.1 or later     | Android Studio 4.1 or later           |
  | iOS                  | iOS 10.15 or later       | Xcode 9.0 or later                    |
  | macOS                | macOS 10.15 or later     | Xcode 9.0 or later                    |
  | Windows              | Windows 7 or later       | Microsoft Visual Studio 2017 or later |

* A camera and a microphone

* A valid Agora account and project. Please refer to [Agora account management](/en/introduction/account) for details.

## Set up your project

This section shows you how to set up your Unity project and install the Agora Video SDK.

**Create a new project**
Refer to the following steps or the [Official Unity documentation](https://docs.unity3d.com/hub/manual/AddProject.html#add-projects) to create a Unity project.

1. Open Unity and click **New**.

2. Enter the following details:
   * **Project name** : The name of the project.
   * **Location** : Project storage path.
   * **Template** : The project type. Select **3D**.

3. Click **Create project**.

**Add to an existing project**
To open your existing project:

1. In the **Projects** window, click the **Open** button in the top-right corner.

2. Browse your file manager and select the folder of the project you want to open.

3. Confirm your selection to add the project to the **Projects** window and open it in the Unity Editor.

### Install the SDK

1. Go to the [Download SDKs](/en/api-reference/sdks?product=video\&platform=unity) page and download the latest version of the Unity SDK.
2. In Unity Editor, navigate to **Assets** > **Import Package** > **Custom Package**, and select the unzipped SDK.

   All plugins are selected by default. Deselect any plugins you don't need, then click **Import**.

## Implement Broadcast Streaming

This section guides you through the implementation of basic real-time audio and video interaction in your game.

The following figure illustrates the essential steps:

<Accordions>
  <Accordion title="Quick start sequence">
    ![Quick start sequence](https://assets-docs.agora.io/images/video-sdk/quick-start-sequence.svg)
  </Accordion>
</Accordions>

This guide includes [complete sample code](#complete-sample-code) that demonstrates implementing basic real-time interaction. To understand the core API calls in the sample code, review the following implementation steps.

Before proceeding, create and set up a script to implement Broadcast Streaming and bind the script to the canvas.

**Steps to set up a script**

1. Create a new script and import the UI library.

2. In the **Project** tab, navigate to **Assets > Agora-Unity-RTC-SDK > Code > Rtc**, right-click and select **Create > C# Script**. A new file named `NewBehaviourScript.cs` appears in your Assets.

3. Rename the file to `JoinChannel.cs` and open it.

4. Import the Unity namespaces to access UI components by adding the following code at the top of the file:

   ```csharp
   using UnityEngine;
   using UnityEngine.UI;
   ```

5. Bind the script to the canvas.

In `Assets/Agora-Unity-RTC-SDK/Code/Rtc` , select the `JoinChannel.cs` file, and drag it to the Canvas. In the **Inspector** panel, ensure that the file is bound to the Canvas.

### Import Agora classes

Import the `Agora.Rtc` namespace, which contains various classes and interfaces required to implement real-time audio and video functions.

```csharp
using Agora.Rtc;
```

### Initialize the engine

For real-time communication, create an `IRtcEngine` instance using `RtcEngine.CreateAgoraRtcEngine()`. Then, configure it using `Initialize(context)` with an `RtcEngineContext`, specifying the application context, App ID, and channel profile. In your `JoinChannel.cs` file, add the following code:

```csharp
internal IRtcEngine RtcEngine;
// Fill in your app ID
private string _appID= "";

private void SetupVideoSDKEngine()
{
  // Create an IRtcEngine instance
  RtcEngine = Agora.Rtc.RtcEngine.CreateAgoraRtcEngine();
  RtcEngineContext context = new RtcEngineContext();
  context.appId = _appID;
  context.channelProfile = CHANNEL_PROFILE_TYPE.CHANNEL_PROFILE_LIVE_BROADCASTING;
  context.audioScenario = AUDIO_SCENARIO_TYPE.AUDIO_SCENARIO_DEFAULT;
  // Initialize the instance
  RtcEngine.Initialize(context);
}
```

### Join a channel

To join a channel, call `JoinChannel` with the following parameters:

* **Channel name**: The name of the channel to join. Clients that pass the same channel name join the same channel. If a channel with the specified name does not exist, it is created when the first user joins.

* **Authentication token**: A dynamic key that authenticates a user when the client joins a channel. In a production environment, you obtain a token from a [token server](build/authenticate-users/deploy-token-server.mdx) in your security infrastructure. For the purpose of this guide [Generate a temporary token](/en/introduction/account).

* **User ID**: A 32-bit signed integer that identifies a user in the channel. You can specify a unique user ID for each user yourself. If you set the user ID to `0` when joining a channel, the SDK generates a random number for the user ID and returns the value in the `OnJoinChannelSuccess` callback.

* **Channel media options**: Configure `ChannelMediaOptions` to define publishing and subscription settings, optimize performance for your specific use-case, and set optional parameters.

For Broadcast Streaming, set the `channelProfile` to `CHANNEL_PROFILE_LIVE_BROADCASTING`, the `clientRoleType` to `CLIENT_ROLE_BROADCASTER` (host) or `CLIENT_ROLE_AUDIENCE`, and the `audienceLatencyLevel` to `AUDIENCE_LATENCY_LEVEL_LOW_LATENCY`.

```csharp
// Fill in your channel name
private string _channelName = "";
// Fill in a temporary token
private string _token = "";

public void Join() {
  // Set channel media options
  ChannelMediaOptions options = new ChannelMediaOptions();
  // Start video rendering
  LocalView.SetEnable(true);
  // Automatically subscribe to all audio streams
  options.autoSubscribeAudio.SetValue(true);
  // Automatically subscribe to all video streams
  options.autoSubscribeVideo.SetValue(true);
  // Set the channel profile to live broadcast
  options.channelProfile.SetValue(CHANNEL_PROFILE_TYPE.CHANNEL_PROFILE_LIVE_BROADCASTING);
  //Set the user role as host
  options.clientRoleType.SetValue(CLIENT_ROLE_TYPE.CLIENT_ROLE_BROADCASTER);
  // Set the audience latency level
  options.audienceLatencyLevel.SetValue(AUDIENCE_LATENCY_LEVEL_TYPE.AUDIENCE_LATENCY_LEVEL_LOW_LATENCY);
  // Join a channel
  RtcEngine.JoinChannel(_token, _channelName, 0, options);
}
```

### Subscribe to Video SDK events

Create an instance of the `UserEventHandler` class and set it as the engine event handler. Override the callbacks based on your use-case.

```csharp
// Implement your own callback class by inheriting from the IRtcEngineEventHandler interface
internal class UserEventHandler : IRtcEngineEventHandler
{
  private readonly JoinChannelVideo _videoSample;
  internal UserEventHandler(JoinChannelVideo videoSample)
  {
    _videoSample = videoSample;
  }

  // Triggered when the local user successfully joins a channel
  public override void OnJoinChannelSuccess(RtcConnection connection, int elapsed)
  {
  }

  // Triggered when the SDK receives and successfully decodes the first frame of a remote video
  public override void OnUserJoined(RtcConnection connection, uint uid, int elapsed)
  {
    // Set the display for the remote video
    _videoSample.RemoteView.SetForUser(uid, connection.channelId, VIDEO_SOURCE_TYPE.VIDEO_SOURCE_REMOTE);
    // Start video rendering
    _videoSample.RemoteView.SetEnable(true);
    Debug.Log("Remote user joined");
  }

  // Triggered when the remote user leaves the channel
  public override void OnUserOffline(RtcConnection connection, uint uid, USER_OFFLINE_REASON_TYPE reason)
  {
    // Stop displaying the remote video
    _videoSample.RemoteView.SetEnable(false);
  }
}
```

Create an instance of the user callback class and call `InitEventHandler` to register the event handler.

```csharp
private void InitEventHandler()
{
  UserEventHandler handler = new UserEventHandler(this);
  RtcEngine.InitEventHandler(handler);
}
```

<CalloutContainer type="info">
  <CalloutDescription>
    To ensure that you receive all Video SDK events, register the event handler before joining a channel.
  </CalloutDescription>
</CalloutContainer>

### Display the local video

Use the following code to set up the local video view:

```csharp
internal VideoSurface LocalView;

private void PreviewSelf()
{
  // Enable the video module
  RtcEngine.EnableVideo();
  // Enable local video preview
  RtcEngine.StartPreview();
  // Set up local video display
  LocalView.SetForUser(0, "");
  // Render the video
  LocalView.SetEnable(true);
}
```

### Display remote video

When a remote user joins the channel, the `OnUserJoined` callback is triggered. Call `SetForUser` to set the remote video display and call `SetEnable(true)` to render the video.

```csharp
internal VideoSurface RemoteView;
// When the SDK receives the first frame of a remote video stream and successfully decodes it, the OnUserJoined callback is triggered.
public override void OnUserJoined(RtcConnection connection, uint uid, int elapsed) {
  // Set the remote video display
  _videoSample.RemoteView.SetForUser(uid, connection.channelId, VIDEO_SOURCE_TYPE.VIDEO_SOURCE_REMOTE);
  // Start video rendering
  _videoSample.RemoteView.SetEnable(true);
  Debug.Log("Remote user joined");
}
```

### Leave the channel

Call `LeaveChannel` to leave the current channel.

```csharp
public void Leave() {
  Debug.Log("Leaving " + _channelName);
  // Leave the channel
  RtcEngine.LeaveChannel();
  // Disable the video module
  RtcEngine.DisableVideo();
  // Stop remote video rendering0
  RemoteView.SetEnable(false);
  // Stop local video rendering
  LocalView.SetEnable(false);
}
```

### Handle permissions

To access the camera and microphone, add device permissions to your project according to your target platform.

**Android**
Since version 2018.3, Unity does not actively obtain device permissions from the user. Call `CheckPermission` to check for and obtain the necessary permissions.

1. Include the `UnityEngine.Android` namespace, which contains Android-specific classes for interacting with Android devices from Unity:

   ```csharp
   #if (UNITY_2018_3_OR_NEWER && UNITY_ANDROID)
   using UnityEngine.Android;
   #endif
   ```

2. Create a list of permissions to be obtained.

   ```csharp
   #if (UNITY_2018_3_OR_NEWER && UNITY_ANDROID)
   private ArrayList permissionList = new ArrayList() { Permission.Camera, Permission.Microphone };
   #endif
   ```

3. Check if the required permissions have been granted. If not, prompt the user to grant the necessary permissions.

   ```csharp
   private void CheckPermissions() {
     #if (UNITY_2018_3_OR_NEWER && UNITY_ANDROID)
     foreach (string permission in permissionList) {
       if (!Permission.HasUserAuthorizedPermission(permission)) {
         Permission.RequestUserPermission(permission);
       }
     }
     #endif
   }
   ```

**iOS and macOS**
For iOS and macOS platforms, the Video SDK includes a post-build script named `BL_BuildPostProcess.cs`. When you build and export your Unity project as an iOS project, this script automatically inserts camera and microphone permission entries into the `Info.plist` file, eliminating the need for manual updates.

### Start and stop your game

1. When the game starts, ensure that device permissions have been granted.

   ```csharp
   void Update() {
     CheckPermissions();
   }
   ```

2. To start Broadcast Streaming, initialize the engine and set up the event handler.

   ```csharp
   void Start()
   {
     SetupVideoSDKEngine();
     InitEventHandler();
     PreviewSelf();
   }
   ```

3. To clean up all session-related resources when a user exits the game, call the `Dispose` method of the `IRtcEngine`.

   ```csharp
   void OnApplicationQuit() {
     if (RtcEngine != null) {
       Leave();
       // Destroy IRtcEngine
       RtcEngine.Dispose();
       RtcEngine = null;
     }
   }
   ```

<CalloutContainer type="info">
  <CalloutDescription>
    After calling `Dispose`, you can no longer use any methods or callbacks of the SDK. To use Broadcast Streaming features again, create a new engine instance.
  </CalloutDescription>
</CalloutContainer>

### Complete sample code

A complete code sample demonstrating the basic process of real-time interaction is provided for your reference. To quickly implement the basic functions of real-time Video Calling, copy the following sample code into your project:

**Sample code to implement Broadcast Streaming in your game**

<Accordions>
  <Accordion title="Complete sample code for real-time Broadcast Streaming">
    ```csharp
    using System.Collections;
    using System.Collections.Generic;
    using UnityEngine;
    using UnityEngine.UI;
    using Agora.Rtc;

    #if (UNITY_2018_3_OR_NEWER && UNITY_ANDROID)
    using UnityEngine.Android;
    #endif

    public class JoinChannelVideo : MonoBehaviour
    {
      // Fill in your app ID
      private string _appID= "";
      // Fill in your channel name
      private string _channelName = "";
      // Fill in your Token
      private string _token = "";
      internal VideoSurface LocalView;
      internal VideoSurface RemoteView;
      internal IRtcEngine RtcEngine;

      #if (UNITY_2018_3_OR_NEWER && UNITY_ANDROID)
      private ArrayList permissionList = new ArrayList() { Permission.Camera, Permission.Microphone };
      #endif

      void Start()
      {
        SetupVideoSDKEngine();
        InitEventHandler();
        SetupUI();
        PreviewSelf();
      }

      void Update()
      {
        CheckPermissions();
      }

      void OnApplicationQuit()
      {
        if (RtcEngine != null)
        {
          Leave();
          // Destroy IRtcEngine
          RtcEngine.Dispose();
          RtcEngine = null;
        }
      }

      private void CheckPermissions() {
      #if (UNITY_2018_3_OR_NEWER && UNITY_ANDROID)
          foreach (string permission in permissionList)
          {
            if (!Permission.HasUserAuthorizedPermission(permission))
            {
              Permission.RequestUserPermission(permission);
            }
          }
      #endif
      }

      private void PreviewSelf()
      {
        // Enable video module
        RtcEngine.EnableVideo();
        // Start local video preview
        RtcEngine.StartPreview();
        // Set local video display
        LocalView.SetForUser(0, "");
        // Start rendering video
        LocalView.SetEnable(true);
      }

      private void SetupUI()
      {
        GameObject go = GameObject.Find("LocalView");
        LocalView = go.AddComponent<VideoSurface>();
        go.transform.Rotate(0.0f, 0.0f, -180.0f);
        go = GameObject.Find("RemoteView");
        RemoteView = go.AddComponent<VideoSurface>();
        go.transform.Rotate(0.0f, 0.0f, -180.0f);
        go = GameObject.Find("Leave");
        go.GetComponent<Button>().onClick.AddListener(Leave);
        go = GameObject.Find("Join");
        go.GetComponent<Button>().onClick.AddListener(Join);
      }

      private void SetupVideoSDKEngine()
      {
        // Create IRtcEngine instance
        RtcEngine = Agora.Rtc.RtcEngine.CreateAgoraRtcEngine();
        RtcEngineContext context = new RtcEngineContext();
          context.appId = _appID;
          context.channelProfile = CHANNEL_PROFILE_TYPE.CHANNEL_PROFILE_LIVE_BROADCASTING;
          context.audioScenario = AUDIO_SCENARIO_TYPE.AUDIO_SCENARIO_DEFAULT;
        // Initialize IRtcEngine
        RtcEngine.Initialize(context);
      }

      // Create an instance of the user callback class and set the callback
      private void InitEventHandler()
      {
        UserEventHandler handler = new UserEventHandler(this);
        RtcEngine.InitEventHandler(handler);
      }

      public void Join()
      {
        // Set channel media options
        ChannelMediaOptions options = new ChannelMediaOptions();
        // Start video rendering
        LocalView.SetEnable(true);
        // Publish microphone audio stream
        options.publishMicrophoneTrack.SetValue(true);
        // Publish camera video stream
        options.publishCameraTrack.SetValue(true);
        // Automatically subscribe to all audio streams
        options.autoSubscribeAudio.SetValue(true);
        // Automatically subscribe to all video streams
        options.autoSubscribeVideo.SetValue(true);
        // Set the channel profile to live broadcasting
        options.channelProfile.SetValue(CHANNEL_PROFILE_TYPE.CHANNEL_PROFILE_LIVE_BROADCASTING);
        // Set the user role to broadcaster
        options.clientRoleType.SetValue(CLIENT_ROLE_TYPE.CLIENT_ROLE_BROADCASTER);
        // Join the channel
        RtcEngine.JoinChannel(_token, _channelName, 0, options);
      }

      public void Leave()
      {
        Debug.Log("Leaving _channelName");
        // Disable video module
        RtcEngine.StopPreview();
        // Leave the channel
        RtcEngine.LeaveChannel();
        // Stop remote video rendering
        RemoteView.SetEnable(false);
      }

      // Implement your own callback class by inheriting from the IRtcEngineEventHandler interface class
      internal class UserEventHandler : IRtcEngineEventHandler
      {
        private readonly JoinChannelVideo _videoSample;

        internal UserEventHandler(JoinChannelVideo videoSample)
        {
          _videoSample = videoSample;
        }

        // Callback triggered when an error occurs
        public override void OnError(int err, string msg)
        {
        }

        // Callback triggered when the local user successfully joins the channel
        public override void OnJoinChannelSuccess(RtcConnection connection, int elapsed)
        {
        }

        // OnUserJoined callback is triggered when the SDK receives and successfully decodes the first frame of remote video
        public override void OnUserJoined(RtcConnection connection, uint uid, int elapsed)
        {
          // Set remote video display
          _videoSample.RemoteView.SetForUser(uid, connection.channelId, VIDEO_SOURCE_TYPE.VIDEO_SOURCE_REMOTE);
          // Start video rendering
          _videoSample.RemoteView.SetEnable(true);
          Debug.Log("Remote user joined");
        }

        // Callback triggered when a remote user leaves the current channel
        public override void OnUserOffline(RtcConnection connection, uint uid, USER_OFFLINE_REASON_TYPE reason)
        {
          _videoSample.RemoteView.SetEnable(false);
          Debug.Log("Remote user offline");
        }
      }
    }
    ```
  </Accordion>
</Accordions>

### Create a user interface

Follow these steps to set up a basic UI for your project or to integrate essential UI elements into your existing interface. A basic UI consists of the following components:

* Local view window
* Remote view window
* Buttons to join and leave the channel

**Create a basic UI**

1. Create buttons to join and leave channel

2. In your Unity project, right-click the **Sample Scene** and select **Game Object > UI > Button**. You see a button on the scene canvas.

3. In the **Inspector** panel, rename the button to `Join` and adjust the position coordinates as needed. For example:

   * **Pos X**：`-329`
   * **Pos Y**: `-172`

4. Select the **Text** control of the **Join** button , and change the text to `Join` in the **Inspector** panel.

5. Repeat the steps to create a **Leave** button, using the following positions:

   * **Pos X**：`329`
   * **Pos Y**: `-172`

6. Create local and remote view windows

7. Right-click the Canvas and select **UI > Raw Image**.

8. In the **Inspector** panel, rename `Raw Image` to `LocalView` and adjust its size and position on the canvas. For example:

   * **PosX**：`-250`
   * **Pos Y**: `0`
   * **Width**: `250`
   * **Height**: `250`

9. Repeat the above steps to create a remote view window, name it `RemoteView` , and adjust its position on the canvas:

   * **PosX**：`250`
   * **Pos Y**: `0`
   * **Width**: `250`
   * **Height**: `250`

   Save the changes.

At this point your UI looks similar to the following:

![image](https://assets-docs.agora.io/images/video-sdk/video-call-ui-unity.png)

## Test the sample code

Take the following steps to test the sample code:

1. Obtain a temporary token from Agora Console.

2. In `JoinChannel.cs`, update `_appID`, `_channelName`, and `_token` with the app ID, channel name, and temporary token for your project.

3. In Unity Editor, click **Play** to run your project.

4. Click **Join** to join a channel.

5. Invite a friend to run the demo game on a second device. Use the same `_appID_`, `_token`, and `_channelName` to join. Alternatively, use the [Web demo](https://webdemo.agora.io/basicVideoCall/index.html) to join the same channel.

After your friend joins successfully, you can hear and see each other.

## Reference

This section contains content that completes the information on this page, or points you to documentation that explains other aspects to this product.

* If a firewall is deployed in your network environment, refer to [Connect with Cloud Proxy](build/optimize-quality-and-connection/cloud-proxy.mdx) to use Agora services normally.

### Next steps

After implementing the quickstart sample, read the following documents to learn more:

* To ensure communication security in a test or production environment, best practice is to obtain and use a token from an authentication server. For details, see [Secure authentication with tokens](build/authenticate-users/use-tokens.mdx).

### Sample project

Agora provides open source sample projects on [GitHub](https://github.com/AgoraIO-Extensions/Agora-Unity-Quickstart/tree/main/API-Example-Unity/Assets/API-Example/Examples) for your reference. Download or view the [JoinChannelVideo](https://github.com/AgoraIO-Extensions/Agora-Unity-Quickstart/tree/main/API-Example-Unity/Assets/API-Example/Examples/Basic/JoinChannelVideo) project for a more detailed example.

### API reference

* [`JoinChannel`](https://api-ref.agora.io/en/video-sdk/unity/4.x/API/class_irtcengine.html#api_irtcengine_joinchannel)

* [`EnableVideo`](https://api-ref.agora.io/en/video-sdk/unity/4.x/API/class_irtcengine.html#api_irtcengine_enablevideo)

* [`CreateAgoraRtcEngine`](https://api-ref.agora.io/en/video-sdk/unity/4.x/API/class_irtcengine.html#api_createagorartcengine)

* [`InitEventHandler`](https://api-ref.agora.io/en/video-sdk/unity/4.x/API/class_irtcengine.html#api_irtcengine_addhandler)

* [`SetClientRole`](https://api-ref.agora.io/en/video-sdk/unity/4.x/API/class_irtcengine.html#api_irtcengine_setclientrole)

* [`LeaveChannel`](https://api-ref.agora.io/en/video-sdk/unity/4.x/API/class_irtcengine.html#api_irtcengine_leavechannel)

* [`DisableVideo`](https://api-ref.agora.io/en/video-sdk/unity/4.x/API/class_irtcengine.html#api_irtcengine_disablevideo)

### Frequently asked questions

* [How can I fix black screen issues?](/en/api-reference/faq/quality/video_blank)

* [Why can't I turn on the camera?](/en/api-reference/faq/quality/video_camera)

* [How can I listen for audience joining or leaving a channel?](/en/api-reference/faq/integration/audience_event)

* [How can I solve channel-related issues?](/en/api-reference/faq/integration/channel)

### See also

* [Error codes](reference/error-codes.md)

* [Connection status management](build/optimize-quality-and-connection/connection-status-management.mdx)