⚡ LightTrans

A zero-config LAN bridge between your phone and PC. Transfer text, images and files as easily as chatting — scan a QR code once, then tap an icon. Your data never leaves your local network.

局域网内的手机 ↔ 电脑快递站。 像聊天一样传文字、图片、文件，扫码一次、点图标即用，数据不出家门。

English · 中文

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English

✨ Features

• 📝 Bidirectional text — paste on one device, tap-to-copy on the other, ~1s realtime sync
• 🖼️ Images & files — full-size, zero compression, drag-and-drop on PC, photo picker on phone
• 📱 PWA on iPhone — add to Home Screen once, works like a native app (mDNS stable address: lighttrans.local)
• ⚡ No internet required — pure LAN; works on phone hotspot even when the network is down
• 🔐 Access token — keeps strangers on the same Wi-Fi out (localhost is always trusted)
• 🗑️ Message management — per-device delete, long-press action sheet, batch multi-select
• 🖥️ Silent background service — optional auto-start at Windows login (no window)
• 🌐 Adaptive UI — one page for both phone (440×956pt class) and desktop

🚀 Quick Start (Windows)

Requirements: Python 3.10+, uv (or pip)

git clone https://github.com/Edison-q/LightTrans.git
cd LightTrans
uv sync                # install dependencies
uv run server.py       # or: double-click 启动LightTrans.bat

Then:

1. Your browser opens http://localhost:8765 automatically
2. Click 连接手机 (Connect phone) in the top-right corner
3. Scan the QR code with your iPhone camera → tap Share → Add to Home Screen
4. Done — tap the icon to use it forever (the QR already contains the access token)

Auto-start (optional): create a shortcut to 静默启动.vbs and place it in the Startup folder (Win+R → shell:startup). The service runs silently in the background.

📱 Mobile Usage

Action	How
Send text	Type in the composer, press Enter
Send photo/file	Tap ➕
Copy text	Tap any text bubble
View image	Tap thumbnail → fullscreen preview (✕ / tap blank to close)
Save image to Photos	Open fullscreen → long-press the image
Long-press menu	Copy / Select text / Download / Delete
Partial text select	Long-press → 选择文字 (Select text) → long-press again to drag handles
Batch delete	Tap ☑ 多选 → tick messages → Delete

🛡️ Security

• A random access token is generated on first run (token.txt). Remote devices must present it; localhost bypasses auth.
• The QR code embeds the token, so your phone never types it manually.
• Transport is plain HTTP — it stops casual neighbors, not professional sniffers. Use it on networks you trust (home, personal hotspot).

🏫 Campus & Hotspot Notes

• If devices are on different network segments (e.g. laptop on ethernet, phone on Wi-Fi) or the network blocks client-to-client traffic, direct LAN transfer may fail.
• Fallback that always works: turn on the phone's hotspot, connect the laptop to it — both are now on one LAN. No internet, no data usage, transfers keep working.

🛠 Tech Stack

• Backend: Python + FastAPI + uvicorn, single file (server.py)
• Frontend: vanilla HTML/CSS/JS PWA (index.html, login.html), no build step
• Service discovery: mDNS via zeroconf (lighttrans.local)
• Extras: Pillow (icon, HEIC→JPEG conversion), qrcode (pairing QR)

API

Method	Path	Description
GET	/api/messages?since=N	Incremental message pull
POST	/api/text	Send text {text, sender}
POST	/api/upload	Upload file(s) (multipart)
GET	/api/files/{id}	Download / view file
DELETE	/api/messages	Clear server history
POST	/api/login	Token login {token}
GET	/api/state	URLs + token

🧪 Tests

uv run python test_api.py

🗺 Roadmap

• iOS Shortcuts share-sheet integration (send from any app)
• Push notifications to phone (Bark)
• Two-way clipboard sync
• Dark mode
• Config file (port, history size, receive folder)

📄 License

MIT © Edison-q

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中文

✨ 特性

• 📝 文字双向互传：一边粘贴、另一边点气泡即复制，约 1 秒实时同步
• 🖼️ 图片/文件原样传输：不压缩、不缩水；电脑端拖拽发送，手机端相册选择
• 📱 iPhone 主屏幕 PWA：扫码添加一次，之后点图标即用（mDNS 固定地址 lighttrans.local）
• ⚡ 无需互联网：纯局域网；手机热点下照样传，断网也能用
• 🔐 访问令牌：同 WiFi 陌生人无法访问（本机免令牌）
• 🗑️ 消息管理：单边删除、长按操作面板、多选批量删除
• 🖥️ 静默后台服务：可选开机自启（无窗口）
• 🌐 自适应界面：手机（440×956pt 级别）与电脑共用一页

🚀 快速开始（Windows）

环境要求：Python 3.10+、uv（或 pip）

git clone https://github.com/Edison-q/LightTrans.git
cd LightTrans
uv sync                # 安装依赖
uv run server.py       # 或双击 启动LightTrans.bat

然后：

1. 浏览器自动打开 http://localhost:8765
2. 点右上角「连接手机」
3. iPhone 相机扫码 → 「分享」→「添加到主屏幕」
4. 完成 —— 以后点图标即用（二维码已包含访问令牌）

开机自启（可选）： 给 静默启动.vbs 创建快捷方式，放入启动文件夹（Win+R → shell:startup），服务静默后台运行。

📱 手机端操作

操作	方法
发文字	输入框打字，Enter 发送
发图片/文件	点 ➕
复制文字	点任意文字气泡
查看图片	点缩略图全屏预览（✕ / 点空白关闭）
保存图片到相册	全屏预览时长按图片
长按操作面板	复制 / 选择文字 / 下载 / 删除
部分选择文字	长按 → 选择文字 → 再长按拖动手柄
批量删除	点 ☑ 多选 → 勾选 → 删除

🛡️ 安全说明

• 首次运行自动生成随机访问令牌（token.txt）；局域网设备访问需令牌，本机 localhost 免令牌
• 二维码内嵌令牌，手机扫码后零感知
• 传输为 HTTP 明文：防"路人随手访问"，不防"专业网络嗅探"。建议在信任的网络（家庭、个人热点）使用

🏫 校园网与热点

• 若设备处于不同网段（如电脑插网线、手机连 WiFi）或网络开启设备隔离，局域网直连可能失败
• 永远有效的兜底方案：手机开热点 → 电脑连热点 → 两者即处于同一局域网。无需互联网、不耗流量，断网也能传

🛠 技术栈

• 后端：Python + FastAPI + uvicorn，单文件（server.py）
• 前端：原生 HTML/CSS/JS PWA（index.html、login.html），无需构建
• 服务发现：mDNS（zeroconf，lighttrans.local）
• 其他：Pillow（图标、HEIC→JPG 转换）、qrcode（配对二维码）

🗺 路线图

• iOS 快捷指令分享菜单（任意 App 一键发送）
• 手机推送通知（Bark）
• 双向剪贴板同步
• 深色模式
• 配置文件（端口、历史条数、接收目录）

📄 许可证

MIT © Edison-q