# Second Brain App Second Brain is a full-stack TypeScript monorepo (React frontend + Express backend) for personal knowledge management. Save links, articles, videos and notes; organize them into multiple “brains,” tag and search items, auto-extract URL metadata, and share public collections via unique links. Built with MongoDB, JWT auth, TailwindCSS and TypeScript for a reliable, developer-friendly foundation. ## 🚀 Quick Start 1. **Install dependencies** ```bash npm install ``` 2. **Set up environment** ```bash cp packages/server/.env.example packages/server/.env # Edit .env with your MongoDB URI and JWT secret ``` 3. **Start development** ```bash npm run dev ``` This starts both the server (port 5000) and client (port 3000) concurrently. ## 📁 Project Structure ``` second-brain/ ├── packages/ │ ├── server/ # Express.js backend │ │ ├── src/ │ │ │ ├── models/ # MongoDB schemas │ │ │ ├── routes/ # API endpoints │ │ │ └── middleware/ │ │ └── package.json │ └── client/ # React frontend │ ├── src/ │ │ ├── components/ │ │ ├── contexts/ │ │ └── main.tsx │ └── package.json └── package.json # Workspace root ``` ## 🛠 Tech Stack **Backend:** - Node.js + Express - TypeScript - MongoDB + Mongoose - JWT Authentication - bcrypt for password hashing - Automatic URL metadata extraction **Frontend:** - React 18 - TypeScript - Tailwind CSS - React Router - Axios for API calls - Lucide React icons ## 🔥 Features - **Authentication:** Register/login with JWT - **Multiple Brains:** Organize content into different collections - **Content Types:** Links, articles, videos, notes - **Auto Metadata:** Automatic title/description extraction from URLs - **Safety Moderation:** Groq AI checks shared content safety - **Age Restriction:** Unsafe content is automatically marked 18+ - **Source Health:** Shared links show "Source Deleted" if unreachable - **Search & Filter:** Full-text search and type filtering - **Tags:** Organize items with custom tags - **Sharing:** Share brains publicly with unique URLs - **Responsive:** Works on desktop and mobile ## 🌐 API Endpoints ### Auth - `POST /api/auth/register` - Create account - `POST /api/auth/login` - Sign in ### Brains - `GET /api/brains` - Get user's brains - `POST /api/brains` - Create new brain - `POST /api/brains/:id/share` - Generate share link - `GET /api/brains/shared/:token` - View shared brain ### Items - `GET /api/items` - Get items (with search/filter) - `POST /api/items` - Add new item - `PUT /api/items/:id` - Update item - `DELETE /api/items/:id` - Delete item ## 🚢 Deployment ### Environment Variables ```bash # Server (.env) PORT=5000 MONGODB_URI=mongodb://localhost:27017/second-brain JWT_SECRET=your-super-secret-jwt-key GROQ_API_KEY=your-groq-api-key GROQ_MODERATION_MODEL=llama-3.1-8b-instant # Client (packages/client/.env) VITE_API_BASE_URL=/api VITE_GOOGLE_CLIENT_ID=your-google-client-id ``` ### Build & Deploy ```bash # Build for production npm run build # Start production server npm start ``` ## Chrome Extension A Chrome extension is available at `packages/extension` for one-click capture. ### Load In Chrome 1. Go to `chrome://extensions` 2. Enable **Developer mode** 3. Click **Load unpacked** 4. Select `packages/extension` ### Setup 1. Start backend: `npm run dev` 2. Open extension popup and set API URL (default `http://localhost:5000/api`) 3. Login with your Second Brain account 4. Select default brain 5. Click **Add to Brain** on any webpage # secondbrain