0trace

Pure P2P browser chat and file transfer for two people

日本語 | 한국어 | Español | Français

Features

• Pure P2P WebRTC transfer, with no file relay through the server
• One shared session for both chat and file transfer
• No account, no install, open in the browser and use it
• Two-person flow with room code or share link
• Human-friendly 6-character room codes like BOOK23
• URL includes ?code=ROOMCODE so refresh can restore the room context
• Large file streaming support in modern browsers
• Multilingual UI: Chinese, English, Japanese, Korean, Spanish, French

Quick Start

Use Online

Visit 0trace.org

Local Deployment

Method 1: Docker

docker run -d -p 2029:2029 ghcr.io/momo2029/0trace:latest

Then open http://localhost:2029.

Method 2: Build from Source

git clone https://github.com/momo2029/0trace
cd 0trace
./dev.sh

How It Works

1. One side creates a room.
2. 0trace generates a 6-character room code and a share link.
3. The other side opens the link or enters the room code.
4. Both browsers establish a direct WebRTC connection.
5. Chat messages and files appear in the same conversation timeline.

If the page is refreshed, the URL keeps the ?code= parameter so the same browser can try to restore that room. If both sides leave and the room stays empty, it expires automatically after about 5 minutes.

Product Positioning

0trace is intentionally strict:

• Only 2 people per room
• No TURN relay fallback for file data
• No server-side transfer fallback
• If a direct connection cannot be established, both sides need to switch networks and try again

That tradeoff keeps the product simple and keeps file contents off the server, but it also means some network combinations will fail.

Architecture

Browser A <- WebSocket signaling -> Rust backend <- WebSocket signaling -> Browser B
    |                                                                      |
    +------------------- WebRTC P2P data channel (chat + files) -----------+

Tech Stack

• Backend: Rust + Axum + Tokio + WebSocket
• Frontend: Vanilla JavaScript + WebRTC API + File System Access API
• Protocol: WebRTC DataChannel + custom message protocol

See ARCHITECTURE.md for details.

Security And Privacy

• File contents are transferred directly between the two browsers
• The server is used for signaling and room coordination only
• WebRTC uses DTLS/SRTP encrypted transport
• Anyone with the room code or share link can join the room, so treat them as sensitive
• Empty rooms expire after about 5 minutes

Limitations

• Designed for exactly 2 participants
• Pure P2P means some NAT or enterprise network combinations may fail
• When direct connectivity fails, users must switch networks and retry
• Large file streaming depends on modern browser support

Development

./dev.sh
make test
make build

See CONTRIBUTING.md.

License

MIT License

Contributing

Issues and Pull Requests are welcome.

Links

• Demo: https://0trace.org
• GitHub: https://github.com/momo2029/0trace
• Issues: https://github.com/momo2029/0trace/issues