build-zoom-video-sdk-app

name	build-zoom-video-sdk-app
description	Reference skill for Zoom Video SDK. Use after routing to a custom-session workflow when the user needs full control over the video experience rather than an actual Zoom meeting.
triggers	["custom video","video sdk","build video app","video session","video chat","video call","video conferencing","custom video ui","twitter spaces","clubhouse alternative","audio-only room","screen sharing","virtual background","native video sdk"]

/build-zoom-video-sdk-app

Background reference for fully custom video-session products. Prefer plan-zoom-product first when the boundary between Meeting SDK and Video SDK is still unclear.

Build custom video experiences powered by Zoom's infrastructure.

Hard Routing Guardrail (Read First)

• If the user asks for custom real-time video app behavior (topic/session join, custom rendering, attach/detach), route to Video SDK.
• Do not switch to REST meeting endpoints for Video SDK join flows.
• Video SDK does not use Meeting IDs, join_url, or Meeting SDK join payload fields (meetingNumber, passWord).

Meeting SDK vs Video SDK

Feature	Meeting SDK	Video SDK
UI	Default Zoom UI or Custom UI	Fully custom UI (you build it)
Experience	Zoom meetings	Video sessions
Branding	Limited customization	Full branding control
Features	Full Zoom features	Core video features

UI Options (Web)

Video SDK gives you full control over the UI:

Option	Description
UI Toolkit	Pre-built React components (low-code)
Custom UI	Build your own UI using the SDK APIs

Prerequisites

• Zoom Video SDK credentials from Marketplace
• SDK Key and Secret
• Web development environment

Need help with OAuth or signatures? See the zoom-oauth skill for authentication flows.

Need pre-join diagnostics on web? Use probe-sdk before Video SDK join() to reduce first-minute failures.

Start troubleshooting fast: Use the 5-Minute Runbook before deep debugging.

Quick Start (Web)

NPM Usage (Bundler like Vite/Webpack)

import ZoomVideo from '@zoom/videosdk';

const client = ZoomVideo.createClient();
await client.init('en-US', 'Global', { patchJsMedia: true });
await client.join(topic, signature, userName, password);

// IMPORTANT: getMediaStream() ONLY works AFTER join()
const stream = client.getMediaStream();
await stream.startVideo();
await stream.startAudio();

CDN Usage (No Bundler)

WARNING: Ad blockers block source.zoom.us. Self-host the SDK to avoid issues.

# Download SDK locally
curl "https://source.zoom.us/videosdk/zoom-video-1.12.0.min.js" -o js/zoom-video-sdk.min.js

<script src="js/zoom-video-sdk.min.js"></script>

// CDN exports as WebVideoSDK, NOT ZoomVideo
// Must use .default property
const ZoomVideo = WebVideoSDK.default;
const client = ZoomVideo.createClient();

await client.init('en-US', 'Global', { patchJsMedia: true });
await client.join(topic, signature, userName, password);

// IMPORTANT: getMediaStream() ONLY works AFTER join()
const stream = client.getMediaStream();
await stream.startVideo();
await stream.startAudio();

ES Module with CDN (Race Condition Fix)

When using <script type="module"> with CDN, SDK may not be loaded yet:

// Wait for SDK to load before using
function waitForSDK(timeout = 10000) {
  return new Promise((resolve, reject) => {
    if (typeof WebVideoSDK !== 'undefined') {
      resolve();
      return;
    }
    const start = Date.now();
    const check = setInterval(() => {
      if (typeof WebVideoSDK !== 'undefined') {
        clearInterval(check);
        resolve();
      } else if (Date.now() - start > timeout) {
        clearInterval(check);
        reject(new Error('SDK failed to load'));
      }
    }, 100);
  });
}

// Usage
await waitForSDK();
const ZoomVideo = WebVideoSDK.default;
const client = ZoomVideo.createClient();

SDK Lifecycle (CRITICAL ORDER)

The SDK has a strict lifecycle. Violating it causes silent failures.

1. Create client:     client = ZoomVideo.createClient()
2. Initialize:        await client.init('en-US', 'Global', options)
3. Join session:      await client.join(topic, signature, userName, password)
4. Get stream:        stream = client.getMediaStream()  ← ONLY AFTER JOIN
5. Start media:       await stream.startVideo() / await stream.startAudio()

Common Mistake (Silent Failure):

// ❌ WRONG: Getting stream before joining
const client = ZoomVideo.createClient();
await client.init('en-US', 'Global');
const stream = client.getMediaStream();  // Returns undefined!
await client.join(...);

// ✅ CORRECT: Get stream after joining
const client = ZoomVideo.createClient();
await client.init('en-US', 'Global');
await client.join(...);
const stream = client.getMediaStream();  // Works!

Video Rendering (Event-Driven)

The SDK is event-driven. You must listen for events and render videos accordingly.

Use attachVideo() NOT renderVideo()

import { VideoQuality } from '@zoom/videosdk';

// Start your camera
await stream.startVideo();

// Attach video - returns element to append to DOM
const element = await stream.attachVideo(userId, VideoQuality.Video_360P);
container.appendChild(element);

// Detach when done
await stream.detachVideo(userId);

Required Events

// When other participant's video turns on/off
client.on('peer-video-state-change', async (payload) => {
  const { action, userId } = payload;
  if (action === 'Start') {
    const el = await stream.attachVideo(userId, VideoQuality.Video_360P);
    container.appendChild(el);
  } else {
    await stream.detachVideo(userId);
  }
});

// When participants join/leave
client.on('user-added', (payload) => { /* check bVideoOn */ });
client.on('user-removed', (payload) => { stream.detachVideo(payload.userId); });

See web/references/web.md for complete event handling patterns.

Key Concepts

Concept	Description
Session	Video session (not a meeting)
Topic	Session identifier (any string you choose)
Signature	JWT for authorization
MediaStream	Audio/video stream control

Session Creation Model

Important: Video SDK sessions are created just-in-time, not in advance.

Aspect	Video SDK	Meeting SDK
Pre-creation	NOT required	Create meeting via API first
Session start	First participant joins with topic	Join existing meeting ID
Topic	Any string (you define it)	Meeting ID from API
Scheduling	N/A - sessions are ad-hoc	Meetings can be scheduled

How Sessions Work

1. No pre-creation needed: Sessions don't exist until someone joins
2. Topic = Session ID: Any participants joining with the same topic string join the same session
3. First join creates it: The session is created when the first participant joins
4. No meeting ID: There's no numeric meeting ID like in Zoom Meetings

// Session is created on-the-fly when first user joins
// Any string can be the topic - it becomes the session identifier
await client.join('my-custom-session-123', signature, 'User Name');

// Other participants join the SAME session by using the SAME topic
await client.join('my-custom-session-123', signature, 'Another User');

Signature Endpoint Setup

The signature endpoint must be accessible from your frontend without CORS issues.

Option 1: Same-Origin Proxy (Recommended)

# Nginx config
location /api/ {
    proxy_pass http://YOUR_BACKEND_HOST:3005/api/;
    proxy_http_version 1.1;
    proxy_set_header Host $host;
}

// Frontend uses relative URL (same origin)
const response = await fetch('/api/signature', { ... });

Option 2: CORS Configuration

// Express.js backend
const cors = require('cors');
app.use(cors({
  origin: ['https://your-domain.com'],
  credentials: true
}));

WARNING: Mixed content (HTTPS page → HTTP API) will be blocked by browsers.

Use Cases

Use Case	Description
Video SDK BYOS (Bring Your Own Storage)	Save recordings directly to your S3 bucket

BYOS (Bring Your Own Storage)

Video SDK feature - Zoom saves cloud recordings directly to your Amazon S3 bucket. No downloading required.

Official docs: https://developers.zoom.us/docs/build/storage/

Prerequisites:

• Video SDK account with Cloud Recording add-on (Universal Credit includes this)
• AWS S3 bucket

Authentication options:

1. AWS Access Key - simpler setup
2. Cross Account Access - more secure (IAM role assumption)

S3 path structure:

Buckets/{bucketName}/cmr/byos/{YYYY}/{MM}/{DD}/{GUID}/cmr_byos/

Key benefits:

• Zero download bandwidth costs
• Direct storage during recording
• Config-only setup (no webhook/download code needed)

Setup location: Developer Portal → Account Settings → General → Communications Content Storage Location

See ../general/use-cases/video-sdk-bring-your-own-storage.md for complete setup guide.

Detailed References

UI & Components

• references/ui-toolkit.md - Pre-built UI components (Web)
• references/triage-intake.md - What to ask first (turn vague reports into answers)
• references/session-lifecycle.md - Correct API ordering + event-driven rendering
• references/licensing-and-entitlements.md - License/admin prerequisites
• references/token-contract-test-spec.md - Shared backend token contract and cross-platform smoke test

Platform Guides

• references/authorization.md - Video SDK JWT generation
• web/SKILL.md - Web Video SDK (JavaScript/TypeScript)
  • web/SKILL.md - Complete documentation navigation
  • web/examples/react-hooks.md - Official React hooks library
  • web/examples/framework-integrations.md - Next.js, Vue/Nuxt patterns
• react-native/SKILL.md - React Native Video SDK (mobile wrapper, helper/event architecture)
  • react-native/SKILL.md - React Native documentation navigation
  • react-native/examples/session-join-pattern.md - Tokenized session join flow
• flutter/SKILL.md - Flutter Video SDK (mobile wrapper, event-driven architecture)
  • flutter/SKILL.md - Flutter documentation navigation
  • flutter/examples/session-join-pattern.md - Tokenized session join flow
• android/SKILL.md - Android Video SDK (native mobile custom UI, tokenized sessions)
• ios/SKILL.md - iOS Video SDK (native mobile custom UI, delegate-driven lifecycle)

Sample Repositories

Official (by Zoom)

Type	Repository	Stars
Web	videosdk-web-sample	137
Web NPM	videosdk-web	56
Auth	videosdk-auth-endpoint-sample	23
UI Toolkit Web	videosdk-zoom-ui-toolkit-web	17
UI Toolkit React	videosdk-zoom-ui-toolkit-react-sample	17
Next.js	videosdk-nextjs-quickstart	16
Telehealth	VideoSDK-Web-Telehealth	11
Linux	videosdk-linux-raw-recording-sample	-

Full list: See general/references/community-repos.md

Resources

• Official docs: https://developers.zoom.us/docs/video-sdk/
• Developer forum: https://devforum.zoom.us/

Environment Variables

• See references/environment-variables.md for standardized .env keys and where to find each value.

Linux Operations

• linux/RUNBOOK.md - Linux platform preflight and debugging checklist.