Lanvan — LAN File Transfer Server

Demo video: Watch on YouTube

A fast, private file-sharing server that runs on your local network. No internet, no cloud, no accounts. Upload, download, and share files between any devices on the same Wi-Fi in seconds.

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Features

• Fast LAN transfer — direct device-to-device, no internet needed
• Folder upload — upload entire folder trees, subdirectories preserved
• Mobile friendly — works in any browser on phones, tablets, and PCs
• Clipboard sync — share copied text between devices in real time
• QR codes — scan to connect instantly on mobile
• mDNS discovery — access via http://lanvan.local on supported devices
• Cross-platform — Windows, Linux, macOS, Android (Termux)
• No size limits — only limited by your storage space

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Requirements for PC

Requirement	Minimum	Recommended
Python	3.9	3.11+
Free disk space	50 MB	1 GB+
Network	Local Wi-Fi or LAN	Wi-Fi 5 / Ethernet

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Installation

Windows, macOS, Linux

1. Clone the repository

git clone https://github.com/P7XCKD/lanvan.git
cd lanvan

2. Create a virtual environment (strongly recommended)

python -m venv .venv

3. Activate the virtual environment

# Windows (PowerShell)
.\.venv\Scripts\Activate.ps1

# Windows (Command Prompt)
.\.venv\Scripts\activate.bat

# macOS / Linux
source .venv/bin/activate

4. Install dependencies

pip install -r requirements.txt

5. Run the server

python run.py

On Windows you can also use py run.py — the launcher will auto-activate the venv if it exists.

The terminal will display the server address and a QR code:

[OK] Server running at:
Local:  http://127.0.0.1
LAN:    http://192.168.1.x

[INFO] Type 'close' | quit | shut | stop  to stop. Or press Ctrl+C.

Open the LAN address in any browser on the same network to start transferring files.

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Android (Termux)

1. Install Termux from F-Droid (recommended) or Google Play.

2. Open Termux and run the setup script

pkg update -y && pkg install -y git python
git clone https://github.com/P7XCKD/lanvan.git ~/lanvan
cd ~/lanvan/docs/termux && bash setup-android.sh

3. Start the server

cd ~/lanvan
python run.py

Tip: Run termux-wake-lock before starting to prevent Android from killing the server.

On Android, use the direct IP address (http://192.168.x.x) — mDNS .local domains usually do not work on Android.

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Stopping the Server

Method	Action
Keyboard shortcut	Press Ctrl+C in the terminal
Console command	Type close, quit, shut, stop, or exit and press Enter

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Connecting from Other Devices

1. Make sure all devices are on the same Wi-Fi network.
2. Open a browser on the other device and go to:
   • http://Lanvan.local (Windows/macOS/iOS — via mDNS)
   • http://192.168.x.x (direct IP, works everywhere)
   • Scan the QR code shown in the terminal
3. Start uploading or downloading files.

If other devices cannot connect (Windows host)

Run the included connectivity fixer as Administrator:

fix_guest_connectivity.bat

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HTTPS / SSL (optional)

# Start with HTTPS
python run.py https

# iOS compatibility mode (HTTP, optimised for Safari)
python run.py ios

Certificates are auto-generated on first HTTPS run and stored in certs/.

iOS Safari requires either HTTP mode or a trusted certificate. Use python run.py ios for the best iOS experience.

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⚡ Speed & Performance Optimization

To achieve the absolute maximum file transfer rates over your local network:

1. Use HTTP Mode (Default): Run the server without https (python run.py). This avoids cryptographic CPU overhead on older/low-power devices, boosting speeds by 20% to 50%.
2. Install uvloop (Linux, macOS, and Termux):

   pip install uvloop

   This replaces Python's default event loop with a C-based loop built for speed, accelerating FastAPI throughput by 2-4x.
3. Use a Wired Host Connection: Connect the host machine via Ethernet instead of Wi-Fi. This eliminates wireless packet collisions and frees up bandwidth for receiving clients.
4. Use 5 GHz Wi-Fi: Ensure client devices are connected to the 5 GHz Wi-Fi band of your router rather than 2.4 GHz.

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Project Structure

lanvan/
  ├── app/                  # Main FastAPI Application Core
  │   ├── core/             # Cryptography, validation, streaming merge, and atomic locks
  │   ├── routers/          # API route controllers (files, pages, clipboard, etc.)
  │   ├── ws_manager/       # WebSocket states for real-time clipboard & updates
  │   ├── utils/            # Platform checks, memory limits, and Zeroconf mDNS
  │   ├── static/           # CSS styles, images, and client JS modules
  │   └── templates/        # Jinja2 layout components (base.html, index.html)
  ├── certs/                # SSL certificate config and generation scripts
  ├── data/                 # Operational user files & db stores (uploads, clipboards)
  ├── docs/                 # Platform setups and requirements manifests
  │   └── termux/           # Automated setup assets for Android Termux
  ├── testing/              # Test workspace and unit diagnostic suites
  ├── run.py                # Platform-aware server launcher entry point
  └── qt.py                 # Core component reliability test runner

For detailed architecture descriptions, refer to the documentation in each folder:

• app/: Main FastAPI application core, routes, assets, and Jinja2 views.
  • app/static/js/: Client-side progressive JavaScript architecture.
  • app/templates/: Modular HTML views and skeleton inheritance files.
• certs/: SSL certificate creation configurations and local key generator scripts.
• docs/: Platform configuration checklists, troubleshooting, and setup scripts.
  • docs/termux/: Automated setup assets and scripts for Android Termux.
• testing/: Sandboxed test workspace assets and isolated diagnostic tools.
• run.py: Entry launcher that detects platform targets, sets up venv, and boots uvicorn.
• qt.py: Standard automated component testing suite.

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Troubleshooting

Problem	Fix
Other devices cannot connect	Run fix_guest_connectivity.bat as Administrator (Windows)
Lanvan.local does not resolve	Use the direct IP address instead
Upload fails with 500 error	Check available disk space; see server console for details
Server won't stop on Ctrl+C	Type close in the terminal and press Enter
Clipboard sync not working on Android	Android restricts background clipboard access — use manual copy/paste

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Dependencies

Package	Purpose
fastapi	Web framework
uvicorn[standard]	ASGI server
jinja2	HTML templates
python-multipart	File upload handling
cryptography	AES encryption
psutil	System monitoring
qrcode	QR code generation
zeroconf	mDNS service discovery
aiofiles	Async file I/O
pyperclip	Clipboard operations (desktop)

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License

MIT License — see LICENSE for details.