Jida（即达）

Send, and it's there. · 发出，即达。 · 无需等待，已在彼端。

A privacy-friendly LAN file transfer tool. Send files between devices on the same Wi-Fi / local network right from your browser — no cloud, no accounts, no installation.

简体中文

Why "Jida"

Jida literally means "it arrives right away" — 即 (ji) is immediate, no waiting; 达 (da) is arrival, delivery done.

• No middleman. Data travels end-to-end between devices. There is no "relay", "store" or "proxy" inside the name — privacy and security by default.
• Simplicity is speed. Open it, pick a file, send it. Done. No configuration, no learning curve.
• It's about people. "达" is not just a packet arriving — it's delivery, like handing a parcel to a friend.

Same network, any file, any device, any platform: select → send → it's there.

Features

• Devices appear automatically on the same service / room
• Pair with QR code or short-code rooms
• Relay by default so transfers always work; optional WebRTC direct connection for speed
• Pure LAN — no public internet required
• Windows portable package: end users need no Node.js, just double-click to run

Download

Get the latest Windows portable package from the Releases page:

• Jida-win-x64-<version>.zip — unzip and double-click start.bat, no Node.js required
• SHA256.txt — verify the download checksum

Windows Smart App Control: running the unsigned package may show "Smart App Control blocked an unsafe file". This is normal protection for open-source software. Right-click the .zip → Properties → tick Unblock → OK, then extract (or click "More info" → "Run anyway"). You can also verify the download against SHA256.txt.

For other platforms, run from source (see below).

For end users (Windows portable)

A developer builds the package first:

npm install
npm run pack:win

Output directory: release/Jida-win-x64/

1. Zip that folder and hand it to your users
2. After unzipping, users should open guide.html first (or double-click open-guide.bat)
3. Then double-click start.bat
4. Phone and computer on the same Wi-Fi — scan the QR code or open the LAN address shown in the window

Detailed walkthrough: docs/使用说明书.html (copied to root as guide.html in the package).

For developers (run from source)

Requirements

• Node.js 20+
• Devices connected to the same local network

Quick start

npm install

# Dev mode (frontend hot-reload + backend)
npm run dev
# Open http://127.0.0.1:5173 in a browser

# Production build and start
npm run build
npm start
# e.g. http://192.168.x.x:3000

Usage

1. Run the service on one machine (npm start, or start.bat in the portable package)
2. The terminal prints LAN addresses and a QR code
3. Other devices open that address in their browser
4. Tap the other device in Nearby devices → pick files → they accept → download

Rooms / short codes

• Default room: lobby
• New room generates a 6-digit code; both sides join the same room
• Or scan a QR code carrying ?room=

Configuration

Env var	Description	Default
PORT	Service port	3000
HOST	Bind address	0.0.0.0

$env:PORT=8080; npm start

Scripts

Command	Description
npm run dev	Dev mode (frontend + backend)
npm run build	Build frontend + compile server
npm start	Production start
npm run typecheck	Type check
npm run pack:win	Build Windows portable package to release/Jida-win-x64

Firewall

If other devices can't open the page, allow inbound access on the service port (default 3000) on the machine running the service.

Notes & limitations

• Browser-based over Wi-Fi; not system-level Bluetooth file transfer
• Keep the page in the foreground during transfers
• Very large files are limited by browser memory
• Recommended for use on trusted local networks only

Tech stack

• Server: Node.js + Fastify + WebSocket
• Frontend: Vite + TypeScript
• Relay chunking + optional WebRTC DataChannel

Roadmap

See ROADMAP.md for planned features, priorities and the versioning convention.

Contributing

Contributions are welcome! See CONTRIBUTING.md for how to get started, and check our security policy for reporting vulnerabilities.

License

MIT © blackteaYES