local-chat

Private local network CLI chat. No server, no logs, just vibes.

Same WiFi, terminal-based, fully encrypted, completely volatile.

Quick Start

npx local-chat

That's it. Create a room or join one automatically discovered on your network.

Features

• Fully local — No external server. Works on the same WiFi only.
• Volatile — Messages exist in memory only. Leave the room, they're gone.
• Encrypted — AES-256-GCM on all messages. Packet sniffing gets you nothing.
• Password rooms — Optional password protection with SHA-256 auth.
• Auto discovery — Rooms broadcast via UDP. No IP sharing needed.
• Korean input — Full IME support via Ink.

Usage

Create a room

npx local-chat
# → Create a room → enter room name, optional password, nickname

Join a room (auto-discover)

npx local-chat
# → Join a room → pick from discovered rooms

Join directly

npx local-chat join 192.168.1.5:41567

Commands

| Command | Description | |---------|-------------| | /users | List online users | | /clear | Clear screen | | /help | Show help | | /quit | Leave room |

Shortcuts

| Key | Action | |-----|--------| | Ctrl+C | Exit | | Ctrl+L | Clear screen | | Ctrl+H | Toggle help |

How It Works

Room Creator (Host)                    Participants
┌─────────────────────┐               ┌──────────────┐
│ WebSocket Server    │◄──────ws─────►│ WS Client    │
│ (message relay)     │               └──────────────┘
│                     │               ┌──────────────┐
│ UDP Broadcaster     │──broadcast───►│ UDP Listener  │
│ (room announce)     │  port 41568   └──────────────┘
└─────────────────────┘

• The room creator's machine runs a WebSocket server
• Room info is broadcast via UDP every 3 seconds (port 41568)
• All messages are encrypted with AES-256-GCM
• Password rooms derive keys via PBKDF2; public rooms use a random session key

Security

• Messages encrypted with AES-256-GCM (Node.js built-in crypto)
• Passwords hashed with SHA-256, keys derived with PBKDF2 (100k iterations)
• Nothing written to disk. Ever.
• Network-local only — no internet traffic

Requirements

• Node.js >= 18
• Same WiFi/LAN network

License

MIT