Chat Demo — Real-Time Messenger

A minimal, production-ready real-time chat demo built with Bun, Socket.io, and a Vite + React + shadcn/ui frontend.
No database. No external services. Just connect and chat.

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Quick Start

Make sure Bun is installed (curl -fsSL https://bun.sh/install | bash).

git clone https://github.com/nodiry/chat-demo.git
cd chat-demo
chmod +x run.sh
./run.sh

run.sh installs dependencies for both server/ and client/, then starts them in parallel.

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Access

Service	URL
Frontend	http://localhost:5173
Backend	http://localhost:3005

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How to Use

1. Open http://localhost:5173 in two browser tabs (or two browsers).
2. Tab A: enter name alice, chatting with bob → Start Chatting.
3. Tab B: enter name bob, chatting with alice → Start Chatting.
4. Messages sync in real time. The sidebar shows live ping and render time.
5. Attach a file (up to 100 MB) with the paperclip or paste it from the clipboard. It burns after 15 minutes, or earlier if either user hits the flame button.
6. Messages expire 24 hours after they are sent. When both users close the chat, everything is wiped from memory immediately.

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Tech Stack

Layer	Technology
Runtime	Bun
Backend	Bun native HTTP + Socket.io
Storage	In-memory (Maps) — no database required
Frontend	React 19 + Vite
UI	shadcn/ui + Tailwind CSS v4
Language	TypeScript

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Project Structure

chat-demo/
├── server/          # Bun HTTP + Socket.io backend
│   ├── main.ts      # Single entry point
│   ├── package.json
│   └── README.md    # Socket.io integration guide
│
├── client/          # React SPA
│   ├── src/
│   │   ├── App.tsx          # Login + Chat views
│   │   ├── context/socket.tsx  # Socket context + speed metrics
│   │   └── components/ui/   # shadcn components incl. sidebar
│   ├── package.json
│   └── README.md    # UI & component docs
│
└── run.sh           # One-command launcher

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Commands

Action	Command
Start everything	./run.sh
Backend only	cd server && bun run dev
Frontend only	cd client && bun run dev
Stop	Ctrl+C

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Features

• Zero external dependencies — no MongoDB, Redis, or Memcached needed
• End-to-end encryption: messages are encrypted in the browser (ECDH P-256 + AES-GCM), the server only holds ciphertext
• Burning files: up to 100 MB per file, uploaded in parallel 512 KB chunks with live progress, kept in server memory for 15 minutes (1 GB total cap), can be burnt early
• Auto-cleanup: messages expire after 24 hours and everything is deleted when both users disconnect
• Live speed metrics — socket ping RTT and React render time shown in sidebar
• Dark / light theme — persisted to localStorage
• Peer presence — real-time online/offline indicator

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Docs

• Backend — Socket.io integration guide
• Frontend — UI & component docs

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"Fast servers, clean UI, zero nonsense — just chat."