Modern, responsive chat interface inspired by Open WebUI. Supports OpenAI-compatible API with streaming responses, token analysis, and RAG knowledge bases.

## 🚀 Quick Start (Docker)

```bash
cp .env.example .env
# Edit .env — set your API URL and key
docker compose up --build -d
# Open http://localhost
```

## 🏗️ Development

### Backend
```bash
cd backend
npm install
npm run dev        # port 3001
```

### Frontend
```bash
cd frontend
npm install
npm run dev        # port 5173 (with HMR)
```

## ✨ Features

| Feature | Description |
|---------|-------------|
| 💬 Chat | Streaming messages with markdown & LaTeX |
| ⚙️ Settings | Model, system prompt, temperature, tokens |
| 📊 Token Analysis | Usage stats panel (tokens/sec, context, cost) |
| 📁 Attachments | Image upload + analysis |
| 📚 Knowledge Bases | RAG with multiple bases, file/folder upload |
| 🎨 Theme | Dark mode, accent colors |
| 📱 Responsive | Works on mobile and desktop |

## 🏛️ Architecture

```
┌──────────────────┐         ┌──────────────┐         ┌─────────────────┐
│   Nginx (80)     │────────▶│  Backend     │────────▶│  OpenAI API     │
│   SPA + /api/*   │         │  (Node.js)   │         │  (or compatible)│
└──────────────────┘         └──────────────┘         └─────────────────┘
                                    │
                                    ▼
                             ┌──────────────┐
                             │  sqlite db   │
                             │  (chats)     │
                             └──────────────┘
```

## 🔧 Environment Variables

| Variable | Default | Description |
|----------|---------|-------------|
| `OPENAI_API_URL` | `https://api.openai.com/v1` | API endpoint |
| `OPENAI_API_KEY` | - | Your API key |
| `DEFAULT_MODEL` | `gpt-4o-mini` | Default model ID |
| `JWT_SECRET` | random | JWT secret |
| `NODE_ENV` | `development` | Environment |

## 🐳 Production

```bash
docker compose -f docker-compose.yml up -d --build
```

Nginx serves static frontend + proxies `/api` to backend.

## 📂 Project Structure

```
├── frontend/           # Vite + React + TypeScript + Tailwind
│   ├── src/components/ # Chat, UI, Layout components
│   ├── src/stores/     # Zustand store
│   ├── src/services/   # API client
│   └── Dockerfile
├── backend/            # Express + proxy + chat storage
│   ├── src/index.js    # Main server
│   └── Dockerfile
├── nginx/              # Reverse proxy config
└── docker-compose.yml  # Full stack
```

## 📜 License

MIT