Personal project · Open source
Relay — Real-Time Text & P2P File Sharing
A privacy-first collaboration web app featuring live shared notepad sync and direct peer-to-peer file transfer up to 100 MB via WebRTC data channels. No accounts, no logins, and zero files stored on servers.
Why I built Relay
Whenever I worked on public computers in university labs or library terminals, I ran into the same frustrating barrier: I needed to transfer a piece of code, a lecture note, or a file between the lab machine and my own phone or laptop.
The default solution for most students was scanning a QR code to open WhatsApp Web or logging into personal email. But doing that on a public machine always felt uncomfortable. Shared computers carry real privacy risks: people forget to log out, keyloggers can capture credentials, browser history syncs personal data, and anyone nearby can see private chats on a large monitor.
I didn't feel good exposing my personal accounts just to send a quick file. So I built Relay to solve it: open a clean URL, pair devices in seconds with a short room code, paste text or drop a file, and close the tab. No phone number, no login, and zero traces left behind.
What I built
- Instant peer-to-peer file transfer up to 100 MB directly between browser tabs using WebRTC
- Zero accounts or logins required — no phone numbers, personal credentials, or passwords
- Real-time shared notepad with live keystroke synchronization powered by Socket.IO
- True privacy: files flow directly device-to-device and never get saved on any server database
- Leave no trace: closing the browser tab leaves zero active sessions or cached personal data on public computers
- Fast room pairing via simple 6-digit room codes or shareable direct URLs
Stack
- WebRTC
- Socket.IO
- React
- Node.js
- P2P Transfer
- Privacy-first
Technologies I used
- React and Tailwind CSS for a fast, responsive user interface
- WebRTC Data Channels for direct, encrypted browser-to-browser file transfers
- Socket.IO and WebSockets for real-time notepad text synchronization
- Node.js and Express for room coordination and WebRTC signaling
- Render Cloud for lightweight, reliable hosting
I built Relay as a personal utility to solve a real everyday problem. It is fully open-source and free for anyone who needs to quickly transfer files and notes between devices without compromising their privacy.