SecondBrain

A lightweight "Personal Second Brain" web application for the CEO, built with Next.js + FastAPI.

Tech Stack

• Frontend: Next.js (App Router) + Tailwind CSS + Shadcn/ui
• Backend: Python FastAPI
• Database: SQLite (dev) / PostgreSQL (prod)
• RAG: LightRAG (from RAG-Anything)

Project Structure

SecondBrain/
├── backend/
│   ├── app/
│   │   ├── api/
│   │   │   └── endpoints/
│   │   │       ├── notes.py
│   │   │       ├── rag.py
│   │   │       └── health.py
│   │   ├── core/
│   │   │   ├── config.py
│   │   │   └── security.py
│   │   ├── db/
│   │   │   ├── base.py
│   │   │   ├── connection.py
│   │   │   └── session.py
│   │   ├── models/
│   │   │   ├── note.py
│   │   │   └── user.py
│   │   ├── schemas/
│   │   │   ├── note.py
│   │   │   └── rag.py
│   │   ├── services/
│   │   │   ├── note_service.py
│   │   │   └── rag_service.py
│   │   └── main.py
│   ├── requirements.txt
│   └── .env.example
├── frontend/
│   ├── src/
│   │   ├── app/
│   │   │   ├── (dashboard)/
│   │   │   │   ├── inbox/
│   │   │   │   ├── archive/
│   │   │   │   └── search/
│   │   │   ├── api/
│   │   │   ├── layout.tsx
│   │   │   └── page.tsx
│   │   ├── components/
│   │   │   ├── ui/
│   │   │   ├── notes/
│   │   │   └── rag/
│   │   ├── lib/
│   │   │   ├── api.ts
│   │   │   └── utils.ts
│   │   └── types/
│   │       └── index.ts
│   ├── tailwind.config.js
│   ├── tsconfig.json
│   └── package.json
└── README.md

Features

Core Features

• Note Management: Create, read, update, delete notes with Markdown support
• Status Workflow: Inbox → Reviewed → Archived
• Tag System: Organize notes with tags
• Source Tracking: Link notes to original sources

AI-Powered Features

• RAG Integration: Powered by LightRAG from RAG-Anything
• Natural Language Q&A: Query your knowledge base in natural language
• Smart Summaries: AI-generated summaries for notes

API Interface

RESTful API endpoints for external AI Agents:

• POST /api/notes - Create notes (single or batch)
• GET /api/notes - List notes with filters
• GET /api/notes/{id} - Get note details
• PUT /api/notes/{id} - Update note
• DELETE /api/notes/{id} - Delete note
• POST /api/rag/query - RAG Q&A query
• POST /api/rag/index - Index notes for RAG

Getting Started

Backend Setup

cd backend
cp .env.example .env
# Edit .env with your configuration

# Create virtual environment
python -m venv venv
source venv/bin/activate  # or `venv\Scripts\activate` on Windows

# Install dependencies
pip install -r requirements.txt

# Run the server
uvicorn app.main:app --reload

Frontend Setup

cd frontend
npm install
npm run dev

License

MIT License