Unreal C++ SDK Guide

Unreal C++ install, join, render and event handling.

Interface sections generated from the public SDK definitions

Version v1.1.0 · Updated 2026-10-26 · revision 1

The Unreal Engine (C++) SDK has the IRtcEngine + IRtcEngineEventHandler shape with lower-case method names, the same as the C++ surface on Android/Windows.

Prerequisites#

• Unreal Engine 5.2+ (a C++ project; the plugin must be enabled in .uproject).
• Target-platform permissions: the system camera/microphone permission on Windows/macOS; for Android/iOS see each platform's requirements.
• An appId and a token service (see Enable Services and Get Credentials).

Installation#

# planned shape: put the plugin in the project directory
YourGame/Plugins/NimeetRtc/…
# after regenerating the project files, enable the NimeetRtc module in .uproject

Get a token#

The game backend issues the token; the UE client only receives a string. In production a short-lived token is handed out at login and renewed in the onTokenPrivilegeWillExpire callback; do not compile the App Certificate into the client.

Join a channel#

#include "NimeetRtc/IRtcEngine.h"

class FMeetingHandler final : public IRtcEngineEventHandler {
 public:
  void onJoinChannelSuccess(const char* channel, uid_t uid, int elapsed) override {}
  void onUserJoined(uid_t uid, int elapsed) override {}
  void onUserOffline(uid_t uid, USER_OFFLINE_REASON_TYPE reason) override {}
  void onTokenPrivilegeWillExpire(const char* token) override {}
  void onError(int err, const char* msg) override {}
};

void UMeetingSubsystem::Start(const FString& AppId, const FString& Token)
{
    Handler = MakeShared<FMeetingHandler>();
    Engine = createAgoraRtcEngine();

    RtcEngineContext Context;
    Context.appId = TCHAR_TO_UTF8(*AppId);
    Context.eventHandler = Handler.Get();
    Engine->initialize(Context);

    Engine->setChannelProfile(CHANNEL_PROFILE_LIVE_BROADCASTING);
    Engine->enableVideo();
    Engine->startPreview();
    Engine->joinChannel(TCHAR_TO_UTF8(*Token), "weekly-sync", "", 10001);
}

Publishing and subscribing#

Engine->muteLocalAudioStream(true);
Engine->muteLocalVideoStream(true);
Engine->enableLocalVideo(false);
Engine->updateChannelMediaOptions(Options);

Screen sharing: getScreenCaptureSources → startScreenCaptureByDisplayId / startScreenCaptureByWindowId; render the remote picture with the VideoSurface component the plugin provides (or a custom texture callback).

Events#

IRtcEngineEventHandler's C++ virtual functions: onJoinChannelSuccess, onUserJoined, onUserOffline, onFirstRemoteVideoDecoded, onTokenPrivilegeWillExpire, onError, onConnectionStateChanged.

Error handling#

• Synchronous methods return int; 0 means success and a negative value is an Agora error number;
• Asynchronous errors arrive through onError;
• Unimplemented capabilities return -4 (ERR_NOT_SUPPORTED).

Troubleshooting#

Next steps#

• Full interfaces and overloads: API reference for this platform
• Error codes and troubleshooting: Error code table, FAQ
• Issue tokens on your server: Token authentication

Platform information

The public interfaces are aligned with the Agora unreal-cpp API; installation and runtime requirements are listed under Prerequisites above.

Availability

This platform's SDK: Generally available. The examples use the public API; runtime capability follows the published SDK package.

join-channel flow

The method names, parameter types and return values match the API reference for the same platform. Where a method has several overloads, the most common one is shown here; see the API reference for all overloads.

muteRemoteAudioStream(uid: uid_t, mute: bool): int
initialize(config: const LocalSpatialAudioConfig&): int
renewToken(token: const char*): int
enableVideo(): int
joinChannel(token: const char*, channelId: const char*, info: const char*, uid: uid_t): int
leaveChannel(): int
setChannelProfile(profile: CHANNEL_PROFILE_TYPE): int
setClientRole(role: CLIENT_ROLE_TYPE): int
setupLocalVideo(canvas: const VideoCanvas&): int

Events and callbacks

Callbacks are registered on IRtcEngineEventHandler; naming differs by platform, and the full list is in the API reference for the same platform.

Error codes

the platform REST layer uses REST error codes；the SDK layer maps connection/authentication failures to Agora error numbers, for the mapping table see SDK error identifiers per platform。