Screen Sharing

Capture methods, sourceId selection, permissions and common issues per platform.

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

Screen sharing uses a different mechanism on every platform: browsers go through getDisplayMedia (the user picks a source), desktop apps enumerate sources and pin an id, and mobile platforms go through system screen mirroring or recording extensions. This page gives the exact entry-point method names per platform, and covers permissions and common pitfalls.

Prerequisites#

• The SDK for your platform is integrated and token authentication is working.
• Browser: the page runs in a secure context (HTTPS or localhost) and the user gesture starts sharing.
• Desktop: screen-recording permission is granted; mobile: the system screen-mirroring/recording extension is available.

Entry points per platform (method names from the public interface definition)#

Full signatures (including parameter types) live in the API reference for each platform; do not write them from memory.

Web: the three snippets you need most#

import AgoraRTC from '@nimeet/rtc-web';

const client = AgoraRTC.createClient({ mode: 'rtc' });

// 1) Share video only
const screenVideoTrack = await AgoraRTC.createScreenVideoTrack({ encoderConfig: '1080p_1' }, 'disable');
await client.publish(screenVideoTrack);

// 2) Share video and system audio together (Chrome/Edge support this; Safari does not support system audio)
const [videoTrack, audioTrack] = await AgoraRTC.createScreenVideoTrack({ encoderConfig: '1080p_1' }, 'enable');
await client.publish([videoTrack, audioTrack]);

// 3) When the user clicks "Stop sharing" (in the browser toolbar)
screenVideoTrack.on('track-ended', () => {
  client.unpublish(screenVideoTrack);
  screenVideoTrack.close();
});

Always handle track-ended: when the user stops sharing from the browser's native toolbar the track ends by itself, and without a handler you end up "still publishing a dead track".

Electron: pinning the source (the key difference from the browser)#

const sources = await window.nimeetDesktop.getSources({ types: ['screen', 'window'] });
const primary = sources.find((source) => source.isScreen);
const track = await AgoraRTC.createScreenVideoTrack({ electronScreenSourceId: primary.id }, 'disable');
await client.publish(track);

Once electronScreenSourceId is pinned, switching the foreground window does not change what is being shared — this is the behaviour you need for "share a specific PPT window".

Mobile: a different permission model#

• Android: requires the MediaProjection consent dialog plus a foreground service (from Android 14 onwards the FOREGROUND_SERVICE_MEDIA_PROJECTION type is also required). Without a foreground service, moving to the background gets the capture reclaimed immediately.
• iOS: direct screen recording is not possible; a Broadcast Upload Extension must capture the sample buffers, and the app and the extension share state through an App Group. The user starts and stops the broadcast from Control Center.
• HarmonyOS: uses the system screen-recording permission, which must be declared in module.json5 and requested at runtime.

Choosing encoder parameters#

Common issues#

Next steps#

• REST API reference: complete endpoints, parameters and curl.
• Error codes: locate failures by code / HTTP status.
• FAQ: quotas, limits and troubleshooting.