FastAPI-LangChain-QA-Manager

A modern web application built with FastAPI that combines AI-powered question answering with a PostgreSQL database backend.

✨ Key Features

• 🚀 RESTful API endpoints built with FastAPI for high performance and async support
• 🗄️ PostgreSQL database integration using SQLAlchemy ORM
• 🤖 AI-powered question answering using LangChain and OpenAI's GPT models
• ⚡ CRUD operations for managing questions and answers
• 📚 Automatic API documentation with OpenAPI/Swagger UI

🛠️ Tech Stack

• FastAPI: Modern, fast web framework for building APIs
• PostgreSQL: Robust relational database for data persistence
• SQLAlchemy: Powerful SQL toolkit and ORM for Python
• LangChain: Framework for developing applications powered by language models
• OpenAI: State-of-the-art GPT models for natural language processing
• Pydantic: Data validation using Python type annotations

🎯 Application Features

The application enables users to:

1. 📝 Create and manage questions and answers
2. 🤖 Generate AI-powered responses using OpenAI's language models
3. 💾 Store and retrieve QA pairs from PostgreSQL database
4. 🔄 Perform full CRUD operations through RESTful endpoints

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🚀 Getting Started

Prerequisites

1. PostgreSQL Server

   • Download and register server on PostgreSQL
   • Configure database connection in database.py

2. OpenAI API Key

   • Create an OpenAI API key
   • Add it to langchain_answers.py

Installation

1. Install dependencies:

   # Import all directories from pyproject.toml
   poetry install

2. Navigate to project directory:

   cd FastAPIApplication

3. Start the server:

   uvicorn main:app --reload

4. View API documentation:

   • Open your browser and go to http://127.0.0.1:8000/docs
   • Interactive Swagger UI will be available for testing endpoints
   • Inside the caller.ipynb you can also call endpoints through the local session

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📝 Notes

• Ensure all environment variables are properly set
• Check database connection before starting the application
• Make sure OpenAI API key is valid and has sufficient credits