Share Slides

Sync a PDF presentation across every device in the room. The presenter controls the page; participants follow via link or QR code.

Quick start

npm install
npm run dev

• Web app: http://localhost:5173
• API + WebSocket: http://localhost:3001

Flow

1. Start presenting → upload PDF (optional title + PIN).
2. Share the QR code or join link (/j/roomId) — no presenter secret in the QR.
3. Use Next / Previous or arrow keys when you have control.
4. Participants can Take control if the presenter allows it.

Production (single server)

npm run preview   # build + start on port 3001
# open http://localhost:3001

Or:

npm run build
NODE_ENV=production PORT=3001 npm run start

The API and the React app are served from the same port.

Deploy online (Render)

1. Push the repo to GitHub.
2. render.com → New Web Service → connect the repo.
3. Use the render.yaml in the repo (or set build: npm install && npm run build, start: npm run start).
4. Set PUBLIC_URL to your Render URL (e.g. https://share-slides.onrender.com).
5. Deploy. Participants and presenter use the same URL.

Note: On the free tier, the service sleeps when idle; uploaded PDFs are lost on redeploy (ephemeral disk). Fine for demos.

Environment

Variable	Default	Description
PORT	3001	Server port
NODE_ENV	—	Set to production when deployed
WEB_ORIGIN	http://localhost:5173	Extra CORS origin (dev)
PUBLIC_URL	auto from request	Public URL for join links & QR

Security notes

• Presenter token is only in the presenter URL (?t=...), not in the QR.
• Optional room PIN for participants.
• Rooms expire after 24 hours (in-memory; restarts clear rooms).
• PDF access requires PIN or presenter token.

Project layout

apps/server   Express + Socket.io + PDF upload
apps/web      Vite + React + PDF.js viewer
packages/shared  Shared message types