Quickstart

This page provides a step-by-step guide on how to create a basic real-time app using the Agora RTC SDK. The same steps apply whether you're building voice calling, video calling, interactive live streaming, or broadcast streaming — only a few configuration values change based on your use case.

Understand the tech

To start a real-time session, implement the following steps in your app:

• Initialize the engine: Before calling other APIs, create and initialize an 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 and can also subscribe to streams from other hosts.

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

  Note

  For the voice calling and video calling use cases, each user joins as a host.

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

• For streaming applications, set the latency level based on your use case:

  • Interactive live streaming: Optimized for real-time interaction with ultra-low latency. Use this when hosts and audience need to interact quickly, such as in live Q&A sessions, interactive classrooms, or auctions.

  • Broadcast streaming: Optimized for scalability with slightly higher latency. Use this for large-scale events where one-way broadcasting is sufficient, such as concerts, sports events, or news broadcasts.

Prerequisites

• A camera and a microphone.
• A valid Agora account and project. See Agora account management for details.
• Xcode 13.0 or higher.
• An Apple developer account.
• If you use CocoaPods to integrate the SDK, make sure CocoaPods is installed.
• Two devices running macOS 10.10 or higher.

Set up your project

Install the SDK

Use one of the following methods to install the RTC SDK.

Implement Realtime Communication

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

The following figure illustrates the essential steps:

This guide includes 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.

Import Agora framework

Add the following import to your swift file:

import Cocoa
import AgoraRtcKit

Initialize the engine

Call sharedEngine(withAppId:delegate:) to create and initialize an AgoraRtcEngineKit instance. Provide your App ID and an AgoraRtcEngineDelegate implementation to handle SDK events.

var agoraKit: AgoraRtcEngineKit!
let appId = "YOUR_AGORA_APP_ID"

// Initialize the Agora engine
func initializeAgoraVideoSDK() {
    agoraKit = AgoraRtcEngineKit.sharedEngine(withAppId: appId, delegate: self)
}

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 in your security infrastructure. For the purpose of this guide Generate a temporary token.

• 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 didJoinChannel callback.

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

Set the channelProfile, clientRoleType, and audienceLatencyLevel according to your use case:

The following example shows the configuration for interactive live streaming with the broadcaster role:

let channelName = "demo"    // Replace with your actual channel name
let token = "<Authentication token>" // Replace with your token

// Join the channel with specified options
func joinChannel() {
    let options = AgoraRtcChannelMediaOptions()
    // Set the channel profile according to your use case (see table above)
    options.channelProfile = .liveBroadcasting
    // Set the user role to .broadcaster (host) or .audience according to your use case
    options.clientRoleType = .broadcaster
    // Only takes effect when clientRoleType is .audience
    options.audienceLatencyLevel = .low
    // Publish audio captured by microphone
    options.publishMicrophoneTrack = true
    // Publish video captured by camera
    options.publishCameraTrack = true
    // Auto subscribe to all audio streams
    options.autoSubscribeAudio = true
    // Auto subscribe to all video streams
    options.autoSubscribeVideo = true
    // Use a temporary Token to join the channel
    agoraKit.joinChannel(
        byToken: token,
        channelId: channelName,
        uid: 0,
        mediaOptions: options
    )
}

To change a user's role after joining (for example, promoting an audience member to broadcaster), call setClientRole:

let role: AgoraClientRole = .broadcaster
let options = AgoraClientRoleOptions()
options.audienceLatencyLevel = .low
agoraKit.setClientRole(role, options: options)

Subscribe to RTC SDK events

The RTC SDK provides a delegate for handling channel events. To use it, conform to the AgoraRtcEngineDelegate protocol in your class and implement the event methods you want to handle. The following code implements the didJoinChannel, didOfflineOfUid, and didJoinedOfUid callbacks:

// Extension for handling Agora SDK callbacks
extension ViewController: AgoraRtcEngineDelegate {

    // Triggered when the local user successfully joins a channel
    func rtcEngine(_ engine: AgoraRtcEngineKit, didJoinChannel channel: String, withUid uid: UInt, elapsed: Int) {
        print("Successfully joined channel: \(channel) with UID: \(uid)")
    }

    // Triggered when a remote user joins the channel
    func rtcEngine(_ engine: AgoraRtcEngineKit, didJoinedOfUid uid: UInt, elapsed: Int) {
        setupRemoteVideo(uid: uid, view: remoteView)
    }
    // Triggered when a remote user leaves the channel
    func rtcEngine(_ engine: AgoraRtcEngineKit, didOfflineOfUid uid: UInt, reason: AgoraUserOfflineReason) {
        setupRemoteVideo(uid: uid, view: nil)
    }
}

To learn about the other SDK events, see AgoraRtcEngineDelegate.

Enable the video module

Follow the steps below to set up the video module.

1. To enable the video module, call enableVideo.

2. To enable local video preview, call startPreview.

   // Enable video functionality (audio is enabled by default)
   agoraKit.enableVideo()
   // Enable local video preview
   agoraKit.startPreview()

Display the local video

Call setupLocalVideo to initialize the local view and set the local video display properties.

// Configures and starts displaying the local video feed
func setupLocalVideo() {
    let videoCanvas = AgoraRtcVideoCanvas()
    videoCanvas.view = localView
    videoCanvas.uid = 0  // UID 0 is assigned to the local user
    videoCanvas.renderMode = .hidden
    agoraKit.setupLocalVideo(videoCanvas)
}

Display remote video

To initialize the remote user view, call setupRemoteVideo and set the local display properties for the remote user. Use the didJoinedOfUid callback to get the UID of the remote user.

func setupRemoteVideo(uid: UInt, view: UIView?) {
    let videoCanvas = AgoraRtcVideoCanvas()
    videoCanvas.uid = uid
    videoCanvas.view = view // Assign view for joining, set to nil for leaving
    videoCanvas.renderMode = .hidden
    agoraKit.setupRemoteVideo(videoCanvas)
}

Handle permissions

To access the camera and microphone, add the required permissions for real-time interaction. Open the info.plist file from the project navigation bar, edit the property list, to add the required permissions. These permissions are optional. However, if you do not add these permissions, you will not be able to use the corresponding devices.

Configure your macOS project settings by navigating to TARGETS > Project Name > Signing & Capabilities. Enable App Sandbox and Hardened Runtime, and add the necessary permissions as follows:

Start and close the app

When the user launches the app, it joins the channel and starts Realtime Communication. When the user closes the app, it leaves the channel and ends Realtime Communication.

1. To start Video Calling, call the following methods:

   // Initialize the Agora engine
   initializeAgoraVideoSDK()
   // Start the local video preview
   setupLocalVideo()
   // Join an Agora channel
   joinChannel()

2. To leave the channel and release SDK resources when the app is closed, call the following methods:

   // Stop local video preview
   agoraKit.stopPreview()
   // Leave the channel and release session-related resources
   agoraKit.leaveChannel(nil)
   // Release all resources used by the Agora SDK
   AgoraRtcEngineKit.destroy()

Complete sample code

A complete code sample demonstrating the basic process of real-time interaction is provided for your reference. Copy the following code into your ViewController.swift file:

Create a user interface

To connect the sample code to your existing UI, ensure that your ViewController.swift file includes the UIViews used to Display the local video and Display remote video.

Alternatively, use the following sample code to generate a basic user interface. To use this interface, replace the contents of the ViewController.swift file with the following code:

Sample code to create the user interface

import Cocoa
import AgoraRtcKit

// ViewController.swift

class ViewController: NSViewController {

    // UI view for displaying the local video stream
    var localView: NSView!
    // UI view for displaying the remote video stream
    var remoteView: NSView!

    override func viewDidLoad() {
        super.viewDidLoad()

        // Set up the user interface
        setupUI()
    }

    func setupUI() {
        guard let screenFrame = NSScreen.main?.frame else { return } // Ensure screen is available

        // Create the local video view covering the full screen
        localView = NSView(frame: screenFrame)

        // Create the remote video view positioned in the top-right corner
        remoteView = NSView(frame: CGRect(x: self.view.bounds.width - 135, y: 50, width: 250, height: 250))

        // Add video views to the main view
        self.view.addSubview(localView)
        self.view.addSubview(remoteView)
    }
}

Test the sample code

Take the following steps to test the sample code:

1. In your code update the appId and token, with the app ID and temporary token you obtained from Agora Console. Use the same channelName you filled in when generating the temporary token.

2. Click Build to run your project and wait a few seconds for the app installation to complete.

3. Allow the app to access the device's microphone and camera.

4. On a second device, repeat the previous steps to install and launch the client. Alternatively, use the Web demo to join the same channel and test the following use-cases:

   • If users on both devices join the channel as hosts, they can see and hear each other.
   • If one user joins as host and the other as audience, the host can see themselves in the local video window; the audience can see the host in the remote video window and hear the host.

Reference

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

• If a firewall is deployed in your network environment, refer to Connect with Cloud Proxy 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.

Sample project

Agora provides open source sample projects on GitHub for your reference. Download or view the JoinChannelVideo project for a more detailed example.

API reference

• sharedEngine
• joinChannel
• enableVideo
• startPreview
• leaveChannel
• AgoraRtcEngineDelegate

Frequently asked questions

• How can I fix black screen issues?
• Why can't I turn on the camera?
• How can I listen for audience joining or leaving a channel?
• How can I solve channel-related issues?
• How can I set the log file?
• How can I troubleshoot the issue of no sound?

See also

• SDK error codes
• Connection status management