RAG Flask Starter

A Retrieval-Augmented Generation (RAG) chatbot API built with Flask, LlamaIndex, Pinecone, and MongoDB. This project provides a production-ready foundation for building AI-powered conversational applications with document retrieval capabilities.

🚀 Features

• RAG-powered Chat: Contextual responses using document retrieval with LlamaIndex
• Multiple Source Types: Support for PDF, CSV, and Q&A pairs as knowledge sources
• Vector Search: Pinecone integration for efficient similarity search
• Persistent Storage: MongoDB for chat history, user management, and index storage
• Streaming Responses: Real-time token streaming for chat responses
• Rate Limiting: Built-in rate limiting with Flask-Limiter
• Authentication: JWT-based authentication with admin and user roles
• reCAPTCHA Support: Google reCAPTCHA validation middleware
• CORS Enabled: Cross-Origin Resource Sharing support
• Production Ready: Gunicorn (Linux) and Waitress (Windows) server support

📋 Prerequisites

• Python 3.11+
• MongoDB instance
• Pinecone account and API key
• Perplexity API key (for LLM)
• (Optional) Google reCAPTCHA keys

🛠️ Installation

1. Clone the repository

   git clone https://github.com/marco-bertelli/rag.flask-start.git
   cd rag.flask-start
   

2. Create a virtual environment

   python -m venv venv
   
   # Windows
   venv\Scripts\activate
   
   # Linux/Mac
   source venv/bin/activate
   

3. Install dependencies

   pip install -r requirements.txt
   

4. Configure environment variables

   Create a .env file in the root directory:

   # MongoDB
   MONGODB_URI=mongodb+srv://your-connection-string
   MONGODB_DATABASE=your-database-name
   
   # Security
   SECRET_KEY=your-jwt-secret-key
   
   # Pinecone
   PINECONE_API_KEY=your-pinecone-api-key
   PINECONE_ENV=your-pinecone-environment
   
   # Perplexity (LLM)
   PERPLEXITY_API_KEY=your-perplexity-api-key
   
   # OpenAI (optional)
   OPENAI_API_KEY=your-openai-api-key
   
   # reCAPTCHA (optional)
   RECAPTCHA_SECRET_KEY=your-recaptcha-secret-key
   

🚀 Running the Application

Development (Windows)

python windows_waitress_start.py

Production (Linux/Heroku)

gunicorn --preload --max-requests 500 --max-requests-jitter 5 -t 3 --worker-class gthread --timeout 120 index:app

The server will start on port 8080.

📚 API Endpoints

Chat Endpoints

Method	Endpoint	Description	Auth
GET	/chats/me	Get current user's chat	User Token
GET	/chats/me/history	Get chat history	User Token
GET	/chats/guest	Create a guest chat session	None
GET	/chats/<chatId>/answer?answer=<query>	Query the chatbot (streaming)	None
PUT	/chats/message/<messageId>/feedback	Set message feedback (good/bad)	None

Source Management Endpoints (Admin Only)

Method	Endpoint	Description	Auth
POST	/index/source/<sourceType>	Add a new source to the index	Admin Token
DELETE	/index/source/<sourceId>	Remove a source from the index	Admin Token

Source Types

• qa: Question-Answer pairs

  { "question": "What is RAG?", "answer": "RAG stands for..." }
  

• csv: CSV file with questions and answers columns

  { "path": "https://example.com/data.csv" }
  

• pdf: PDF document

  { "path": "https://example.com/document.pdf" }
  

🏗️ Project Structure

rag.flask-start/
├── app.py                 # Flask app configuration
├── index.py               # Application entry point
├── index_manager.py       # LlamaIndex setup and management
├── conf.py                # Environment configuration loader
├── windows_waitress_start.py  # Windows server startup
├── Procfile               # Heroku/Gunicorn configuration
├── requirements.txt       # Python dependencies
├── data/                  # Sample data files
│   └── rules.pdf          # Initial document for indexing
├── apis/
│   ├── chats.py           # Chat API endpoints
│   └── sources.py         # Source management endpoints
├── middlewares/
│   ├── auth_middleware.py # JWT authentication
│   └── re_captcha.py      # reCAPTCHA validation
├── mongodb/
│   └── index.py           # MongoDB operations
└── utils/
    ├── chat_history_parser.py  # Chat history formatting
    ├── mongo_parsers.py        # MongoDB JSON encoder
    ├── parsers.py              # Document parsing utilities
    ├── validators.py           # Input validation
    └── vector_database.py      # Pinecone/MongoDB vector store setup

⚙️ Configuration

LLM Settings

The project uses Perplexity's mixtral-8x7b-instruct model by default. Configuration is in index_manager.py:

llm = Perplexity(
    api_key=os.getenv("PERPLEXITY_API_KEY"), 
    model="mixtral-8x7b-instruct", 
    temperature=0.2
)

Embedding Model

Uses the local HuggingFace model BAAI/bge-small-en-v1.5 for embeddings:

Settings.embed_model = "local:BAAI/bge-small-en-v1.5"

Rate Limits

Rate limits are configured in apis/chats.py:

• /chats/me: 5 requests per minute
• /chats/me/history: 15 requests per minute
• /chats/<chatId>/answer: 10 requests per minute

🔐 Authentication

The API uses JWT tokens for authentication. Include the token in the Authorization header:

Authorization: Bearer <your-jwt-token>

User Roles

• User: Can access chat features
• Admin: Can manage knowledge sources (add/delete)
• Guest: Limited access with temporary chat sessions

📦 Dependencies

Key dependencies include:

• Flask: Web framework
• LlamaIndex: RAG framework
• Pinecone: Vector database
• PyMongo: MongoDB driver
• Flask-Limiter: Rate limiting
• Flask-CORS: CORS support
• PyJWT: JWT authentication
• llmsherpa: PDF parsing
• Transformers & PyTorch: ML models

🚢 Deployment

Heroku

The project includes a Procfile for Heroku deployment:

web: gunicorn --preload --max-requests 500 --max-requests-jitter 5 -t 3 --worker-class gthread --timeout 120 index:app

Docker (Custom)

Create a Dockerfile:

FROM python:3.11-slim

WORKDIR /app
COPY requirements.txt .
RUN pip install -r requirements.txt

COPY . .

CMD ["gunicorn", "--preload", "-t", "120", "index:app"]

📄 License

This project is open source and available under the MIT License.

👤 Author

Marco Bertelli

• GitHub: @marco-bertelli

🤝 Contributing

Contributions, issues, and feature requests are welcome! Feel free to check the issues page.

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