Unreal Blueprint SDK Guide

Unreal Blueprint nodes, install and limitations.

Interface sections generated from the public SDK definitions

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

Unreal Engine (Blueprint) is the blueprint exposure layer of the same C++ engine: method names are capitalized (Initialize, JoinChannelWithOptions) and events are exposed to blueprints as delegates.

Prerequisites#

• Unreal Engine 5.2+ with the NimeetRtc plugin enabled.
• Shares the runtime library with the C++ side; the permission requirements are the same.
• An appId and a token service (see Enable Services and Get Credentials).

Installation#

YourGame/Plugins/NimeetRtc/…
# regenerate the project files → enable it in .uproject → a "Nimeet RTC" category appears in the editor

Get a token#

Do not hardcode the token in a blueprint. Recommended: get the backend-issued token during login, store it in a string variable on GameInstance, and pass it as an argument of JoinChannelWithOptions when joining.

Join a channel#

Blueprint node order (every node name matches the interface definition):

1. Initialize (arguments: AppId, optional log configuration)
2. SetChannelProfile (ChannelProfileLiveBroadcasting)
3. EnableVideo
4. StartPreview
5. JoinChannelWithOptions (Token, ChannelId, Uid, ChannelMediaOptions)

The corresponding C++ implementation (you can wrap it in your own Actor):

Engine->Initialize(Context);
Engine->SetChannelProfile(CHANNEL_PROFILE_LIVE_BROADCASTING);
Engine->EnableVideo();
Engine->StartPreview();
Engine->JoinChannelWithOptions(Token, ChannelId, Uid, Options);

Publishing and subscribing#

Blueprint nodes: MuteLocalAudioStream, MuteLocalVideoStream, EnableLocalVideo, UpdateChannelMediaOptions. Screen sharing: GetScreenCaptureSources (returns the source list) → StartScreenCaptureByDisplayId / StartScreenCaptureByWindowId.

Events#

Blueprint events (Event nodes):

Error handling#

• OnError gives err (the Agora error number) and msg;
• Synchronous nodes return int, and a negative value is an error;
• Unimplemented capabilities return -4 (ERR_NOT_SUPPORTED); the blueprint sees a failure instead of a silent success.

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-blueprint 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.

JoinChannel(token: const FString&, channelId: const FString&, uid: int64): int
LeaveChannel(): int
EnableVideo(): int
Initialize(context: const FRtcEngineContext&): int
MuteRemoteAudioStream(uid: int64, mute: bool): int
RenewToken(token: const FString&): int
SetChannelProfile(profile: ECHANNEL_PROFILE_TYPE): int
SetClientRole(options: FClientRoleOptions, clientroletype?: ECLIENT_ROLE_TYPE): int
SetupLocalVideo(canvas: const FVideoCanvas&): int

Events and callbacks

This SDK has no event callbacks.

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。