UTD Live Room Kit

A Flutter package for building video live-room experiences, powered by LiveKit and the UTD Stream Engine. It puts a host camera on a full-bleed stage with up to 3 invited co-publisher tiles — give it the required data and you get a fully interactive live room with no extra UI code.

The engine treats a live room as the live_stream product type: an unbounded, seatless stage. There is no seat grid and no participant cap — anyone can watch. The host invites co-publishers onto the stage (audio/video publish), while the room owner promotes moderators. The kit only caps how many guest tiles it draws (maxGuestTiles, default 3); the engine itself is uncapped.

Roles are server-authoritative. Only the verified room owner joins as the publishing host; everyone else joins as audience (watch + chat). The engine clamps any non-owner's claimed role to audience — a client cannot self-grant publish or moderation. Publishing and moderation are decoupled: being added to the stage grants publish only; being promoted to admin grants moderation only (admins are never on camera).

Features

  • Drop-in live-room UI — host camera + up to 3 co-publisher video tiles from required data alone.
  • Stage flow — the host invites viewers onto the stage to co-publish; viewers raise-hand (stage/request) and the host adds them. No server-side queue — a request is a transient _stage_request notification to host/admins.
  • Owner-promoted moderators — the owner promotes configured adminIds to admin (moderate-only, not on camera) via the engine role endpoint.
  • Host force-control — host can mute/unmute or stop a co-publisher's camera/mic, and remove them from the stage.
  • Media controls — microphone & camera with reactive state (Bluetooth-preferring audio routing).
  • Real-time chat — data-channel messages with batching and dedup.
  • Reconnection — tiered: light sync (<15s), full sync (<60s), default force-exit (>60s).
  • Minimize / PiP — minimize to a floating overlay; optional Android OS Picture-in-Picture.
  • Video effects — pairs with utd_video_effects_kit via UTDLiveRoomConfig.buildVideoProcessor (a LiveKit TrackProcessor) for live filters & beauty effects.

Getting started

Add the dependency:

dependencies:
  utd_live_room_kit: ^1.4.0

Credentials — pass your appKey (no backend required)

Ship appId + appKey (the project's publishable app key, from the UTD console). The kit mints tokens directly from the engine with X-App-Key; the engine signs the returned per-user user_token with the project server_secret server-side, so the secret never ships in the app. The kit uses that user_token as the Authorization: Bearer for all in-room calls. No token server to stand up. appKey can't sign tokens or call the S2S API and rotates on its own.

import 'package:utd_live_room_kit/utd_live_room_kit.dart';

UTDLiveRoom(
  appId: '<utd-app-id>',
  appKey: '<utd-app-key>', // publishable; the kit mints tokens itself, no backend needed
  userId: 'user123',
  userName: 'Jane',
  roomId: 'room456',
  roomOwnerId: 'owner789',
  // Identities the OWNER will promote to `admin` (moderators) once they join.
  // Optional. The engine clamps non-owners to `audience`, so these are only
  // honored because the owner promotes them server-side after join.
  adminIds: const {'mod1', 'mod2'},
  config: const UTDLiveRoomConfig(maxGuestTiles: 3),
);

The live room is type: live_stream. The kit mints its token with type: live_stream and sends no seat parameters (seat_count, seat_mode, host_seat are ignored for a live stream — the room is uncapped). The project must have live_stream in its enabled_types in the UTD console, otherwise POST /api/v1/token returns 403 "Type 'live_stream' is not enabled for this project". The same appId / appKey works for every product type the project has enabled — the type is a per-request field, not a separate credential.

See the exported API in lib/utd_live_room_kit.dart — UTDLiveRoom, UTDRoomController, UTDStageApi, UTDMediaController, UTDChatController, and the room/role/participant models.

Stage & roles

A live room has four server-authoritative roles:

Role Publishes Moderates How you get it
host ✅ ✅ The verified room owner (userId == roomOwnerId). Force-upgraded by the engine.
guest ✅ ❌ Host/admin invites you onto the stage.
admin ❌ ✅ The owner promotes you (moderate-only, never on camera).
audience ❌ ❌ Default for everyone non-owner — watch + chat.

Going on stage (co-publish). A viewer raises their hand (POST /api/v1/rooms/:name/stage/request), which fires a transient _stage_request data message to the host/admins (there is no persisted queue). A host/admin then adds them (.../stage/add → role becomes guest, publish granted). Removal (.../stage/remove) or self step-down (.../stage/leave) sends them back to audience. The current publisher set is GET /api/v1/rooms/:name/stage → { members: [{ identity, name, role }] }, and roster changes broadcast a _stage_update data message. These endpoints are live_stream-only (a seated room returns 400).

The kit surfaces the stage through UTDRoomController — inviteToSpeak, requestToSpeak, approveSpeakerRequest, rejectSpeakerRequest — and the raw endpoints via controller.stageApi (UTDStageApi).

Promoting a moderator. Moderation uses the owner-only role endpoint PUT /api/v1/rooms/:name/participants/:identity/role with { role: 'admin' }. The kit does this for you: pass adminIds (or adminIdsResolver / adminIdsNow), and the host client promotes those identities as they join via controller.changeRole. In a stage room this grants moderation but not publish, and the engine refuses (409) an attempt to add an admin to the stage — the two capabilities stay disjoint.

maxGuestTiles is a UI-only cap. It sizes the on-screen tile strip (host + N co-publishers); the engine stage itself is unbounded. There is no seat grid — the host video is the full-bleed background and co-publishers are floating tiles above it.

Config

UTDLiveRoomConfig controls the live experience. Notable fields:

  • maxGuestTiles (default 3) — how many co-publisher tiles to draw (UI cap only; the engine is uncapped).
  • autoHostCamera (default false) — publish on connect vs. self-preview → "Go Live".
  • showGoLiveButton (default true) — render the built-in "Go Live" button during host preview, or let the app drive UTDMediaController.goLive.
  • frontCameraOnJoin / mirrorLocalVideo / hostFit / guestFit — camera & video-fit options.
  • buildVideoProcessor — a LiveKit TrackProcessor factory for live filters & beauty effects (pairs with utd_video_effects_kit).
  • Section/tile overrides — headerWidget, messagesWidget, controlsBarWidget, hostTileBuilder, guestTileBuilder, guestTileFooterBuilder, onStageTap.

Requirements

  • A LiveKit server + UTD Stream Engine token endpoint, with live_stream in the project's enabled_types.
  • Camera & microphone runtime permissions (handled via permission_handler).

Libraries

utd_live_room_kit