CFE Chat 🚀

A fully decentralized, serverless peer-to-peer LAN messenger built with Python 3.13 and CustomTkinter.

Zero configuration. Zero servers. Wire-to-wire encryption. Automatic peer discovery over UDP broadcast.

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✨ Features

• 🔗 Zero-Config Auto-Discovery — UDP broadcasts find peers automatically
• 💬 Room & Private DMs — Broadcast to everyone or direct message a peer
• 📁 Fast File Sharing — Chunked transfers with progress bars
• 🔐 Optional Encryption — Shared-secret Fernet encryption for messages
• 🎨 Beautiful Dark GUI — CustomTkinter modern interface
• ⚡ Real-Time Status — Online/offline indicators + connection quality (RTT)
• 💾 Persistent History — Automatic chat logging & contact saving
• 🔤 Text Formatting — Bold, italic, custom colors
• 📢 Notifications — Sound alerts + title bar flashing
• 🛠️ No Setup Required — Just install & run

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🚀 Quick Start

Install via pip

pip install cfe-chat

Run

cfe-chat

First Time?

1. Enter your nickname
2. Optionally set an encryption password (or leave blank)
3. App auto-discovers peers on your LAN
4. Start chatting!

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📋 Requirements

• Python 3.13+ (3.8+ compatible with minor tweaks)
• pip package manager

Dependencies (auto-installed)

• customtkinter — Modern GUI framework
• cryptography — Optional encryption support
• pillow — Image clipboard support (optional)
• pystray — System tray icon (optional, experimental)

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🎮 Usage

Core Actions

Action	How
Send message	Type → Press Enter or click Send
Private DM	Click a peer's name in sidebar
Format text	Use B / I / Color buttons
Send file	Click "Attach File" button
View history	Switch chats—history loads automatically
Toggle sound	Click 🔔 icon
Clear chat	Click "Clear Chat" button

Keyboard Shortcuts

• Enter — Send message
• Ctrl+V — Paste image from clipboard
• Ctrl+Return — (For future multi-line support)

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🏗️ Architecture

Local Network (LAN / Subnet)
│
├─ Computer A (You)
│  └─ CFE Chat (listening on TCP:2222, UDP:2223)
│
├─ Computer B (Peer)
│  └─ CFE Chat (listening on TCP:2222, UDP:2223)
│
└─ Computer C (Peer)
   └─ CFE Chat (listening on TCP:2222, UDP:2223)

Auto-discovery via UDP broadcast every 2.5 seconds
Direct P2P messaging over TCP
File transfer with chunked streaming

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🔒 Privacy & Security

✅ No cloud. No servers. No tracking.

• All data stays on your computer & LAN
• No internet required
• No analytics or telemetry
• MIT Licensed — fully open source
• Optional encryption available for sensitive chats

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⚙️ Configuration

No configuration files needed. Everything is automatic.

Want to customize? Edit cfe_chat_v5.py:

PORT = 2222                    # TCP server port
BROADCAST_PORT = 2223          # UDP discovery port
FILE_CHUNK_SIZE = 64 * 1024    # File transfer chunk size
DISCOVERY_INTERVAL = 2.5       # Discovery broadcast interval (seconds)
SOCKET_TIMEOUT = 15            # Connection timeout (seconds)
HISTORY_LIMIT = 500            # Max messages per conversation

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📂 Data Storage

All data stored locally in ./chat_data/:

chat_data/
├── log.txt                 # Chat history log
├── history.json            # Message history (500 per conversation)
├── contacts.json           # Saved contacts + last seen
├── error.log               # Error diagnostics
└── received_files/         # Downloaded files

Cross-platform paths are auto-detected (Windows/macOS/Linux).

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⚠️ Known Limitations

System Tray (Experimental)

• May not start reliably on all systems
• Workaround: Run without tray or restart application

Clipboard Image Paste (Experimental)

• Windows: ✅ Works
• Linux: ⚠️ May need xclip or xsel: apt install xclip xsel
• macOS: ⚠️ Requires permission grant
• Workaround: Use "Attach File" button instead

Network Scope

• LAN-only (same subnet)
• Behind strict firewalls may need port forwarding
• VPN/mesh networks supported

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🔧 Troubleshooting

Peers not showing up?

# Check if ports are open (macOS/Linux)
sudo lsof -i :2222
sudo lsof -i :2223

# Windows
netstat -ano | findstr :2222

Restart the app if discovery fails.

Can't send messages?

• Check peer is online (green dot)
• Firewall: Allow TCP 2222 & UDP 2223
• If encryption on/off mismatch: restart app

File transfer fails?

• Check disk space
• Files > 2 GB not supported
• Retry the transfer

App crashes?

• Check Python version: python --version (need 3.8+)
• Check logs: cat chat_data/error.log
• Reinstall: pip install --upgrade cfe-chat

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📦 What Gets Installed?

When you pip install cfe-chat:

/usr/local/bin/cfe-chat          # Executable script
/site-packages/cfe_chat/          # Package directory
├── __main__.py                   # Entry point
├── cfe_chat_v5.py                # Main application
└── requirements.txt              # Dependencies

Run from anywhere: cfe-chat

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🚀 Development

Clone & Run Locally

git clone https://github.com/timmoa-cfe/CFE-Chat.git
cd CFE-Chat
pip install -r requirements.txt
python cfe_chat_v5/cfe_chat_v5.py

Building Package for PyPI

pip install build twine
python -m build
twine upload dist/*

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📊 Performance

Metric	Value
Max concurrent peers	16+
Message latency	<50 ms
File transfer speed	~50 Mbps (LAN-limited)
Memory footprint	60–120 MB
CPU (idle)	<5%

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🛣️ Roadmap

• PyPI package publishing (v5.0)
• IPv6 support
• Message search & filtering
• Better tray integration
• Cross-platform installers (exe, DMG, AppImage)
• Voice/video calls (v6.0+)
• Message reactions & emoji
• Web interface (optional)

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📞 Support

• Telegram: t.me/CFE_Chat
• GitHub Issues: Report bugs
• Documentation: See RELEASE_v5.0.md

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📄 License

MIT License © 2026 timmoa-cfe

Permission to use, modify, and distribute freely. See LICENSE for details.

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Made with ❤️ for LAN communities.

CFE Chat — Zero config. Pure P2P. All local.