@element-hq/matrixrtc-sdk is the call model under Element Call, on its own: MatrixRTC memberships and transports, LiveKit connections, publishing, E2EE keys and the media of every member, as observables. It has no UI. Element Call's own CallViewModel is meant to become one consumer of it. The design is in SdkArchitecture.md, the migration from the view model in SdkMigration.md.

Status: first implementation. createMatrixRTCClient joins the session, connects to the transport, publishes the local media and exposes every member's media; the development harness and its e2e tests in playwright/sdk drive it, and Element Call's own CallViewModel is built on it. It depends on nothing in Element Call's src/.

Using it

import {
  constant,
  createMatrixRTCClient,
  E2eeType,
  MatrixRTCMode,
  ObservableScope,
} from "@element-hq/matrixrtc-sdk";

const scope = new ObservableScope();
const rtcClient = createMatrixRTCClient(
  scope,
  client, // a matrix-js-sdk MatrixClient, logged in and syncing
  room, // the matrix-js-sdk Room, from client.getRoom() once the join has synced
  {
    microphoneEnabled: true,
    cameraEnabled: true,
    audioInputDeviceId$: constant(undefined),
    videoInputDeviceId$: constant(undefined),
    audioOutputDeviceId$: constant(undefined),
    videoProcessor$: constant(undefined),
  },
  {
    encryptionSystem: { kind: E2eeType.PER_PARTICIPANT },
    matrixRTCMode: MatrixRTCMode.Compatibility,
  },
);
rtcClient.join();

rtcClient.remoteMembers$.subscribe((members) => {
  // each member has displayName$, media$ and more; a media track is rendered
  // by handing it a <video> or <audio> element: track.attach(element)
});

// later
rtcClient.leave();
scope.end();

dev/main.ts is this example as a working page.

Development

Everything runs from the repository root. This directory is a pnpm project of its own only so that a host can install it as a git dependency (see pnpm-workspace.yaml).

pnpm dev:sdk              # the harness, https://localhost:3002
pnpm build:sdk            # dist/matrixrtc-sdk.js and dist/types
pnpm test:playwright playwright/sdk   # needs `pnpm backend`

Installing

pnpm add github:element-hq/element-call#<ref>&path:/sdk

The host supplies matrix-js-sdk, livekit-client and rxjs; the build leaves them external.