LAN Chat

CRITICAL: This is a 100% vibe coded project don't run this on the wider internet and never allow untrusted access to this program.

LAN Chat is a lightweight local-network chat app using Deno, WebSockets, and a browser frontend with room-key encryption.

Features

• Account access with username + PIN
• Sign-up and sign-in flow in the UI
• Root admin account with user management:
  • View registered users
  • Delete user accounts (and their messages)
  • Wipe all non-admin users + clear room history
• Persistent account storage using SQLite (backend/chat.sqlite3)
• Room-based chat (General + custom rooms)
• Client-side room-key encryption (AES-GCM via Web Crypto)
• Message replies and spoiler messages
• Notification system:
  • In-app toasts
  • Desktop notifications (optional)
  • Sound notifications via frontend/static/sound/discord_message.mp3
• Per-user mute/unmute
• Local storage for:
  • Username + avatar
  • Theme (WIP)
  • Notification settings
  • Muted users

Root Admin

• Default root account is:
  • Username: root
  • PIN: 0000

Change it immediately in production by updating the value in backend/main.ts.

Deployment

Prerequisites

• Deno

Local Development

1. Run Dev:

   deno task dev

2. Access: Open http://localhost:8000.

LAN Deployment

1. Build Frontend:

   deno task build:fe

2. Start Server:

   deno task start --allow-all

3. Access the App:
   • Locally: http://localhost:8000
   • LAN Access: Use your computer's local IP (e.g., http://192.168.1.5:8000).

Build a Standalone Binary

The binary is compiled with --allow-all, so permissions are baked in at build time and users do not see runtime permission prompts.

1. Build Binary:

   deno task build:bin

2. Run Binary:

   ./bin/lan-chat

3. Access the App:
   • Locally: http://localhost:8000
   • LAN Access: http://<your-local-ip>:8000

GitHub Binary Builds

This repo includes a workflow at .github/workflows/build-binaries.yml that builds binaries for:

• Linux (x86_64-unknown-linux-gnu)
• Windows (x86_64-pc-windows-msvc)
• macOS (x86_64-apple-darwin)

Trigger it with:

• Pushes to master
• Pull requests to master
• Manual run from the Actions tab (workflow_dispatch)

The workflow always uploads compiled binaries as artifacts. For non-PR runs (push to master and workflow_dispatch), it also creates a GitHub prerelease and attaches the binaries there.

Data Persistence

• SQLite database: ./backend/chat.sqlite3
• Uploads: ./frontend/static/uploads

Keyboard Shortcuts

• Enter: Send message
• Shift + Enter: New line
• Alt + S: Toggle spoiler mode
• N: Create room
• T: Focus theme selector
• Esc: Cancel reply
• Alt + Q: Logout

Project Structure

backend/main.ts                 # API + WebSocket server + auth + admin
backend/chat.sqlite3            # SQLite database file
frontend/index.html             # UI layout/styles
frontend/app.ts                 # Frontend logic
frontend/dist/app.js            # Bundled frontend script
frontend/static/sound/*.mp3     # Notification sound assets
frontend/themes/*.css           # Theme files

Notes

• PIN format: numeric, 4-12 digits.
• Usernames: 3-24 chars using letters, numbers, _, -, .
• Message history is in-memory and resets on server restart.