adepojujeremy / fastapi-langchain-db-api-agent

A FastAPI-based agent that queries the Northwind database and integrates multiple public APIs, including authentication-required endpoints. The agent automatically determines the appropriate tool to engage based on the natural language query provided. Deployed on Render and accessible via a single FastAPI endpoint.The application is live and hosted

LangChain-FastAPI-Agent

This repository contains a Python-based LangChain agent that interacts with a SQLite database and various public APIs. The agent is exposed over a single FastAPI endpoint and can process natural language queries to decide whether to query the database or fetch data from a public API.

Features

• Database Querying: Interacts with the Northwind SQLite database to retrieve information based on SQL queries.
• Public API Integration: Fetches data from a public API without authentication.
• Authenticated API Integration: Fetches data from a public API that requires authentication.
• Natural Language Processing: Determines the appropriate action (database query or API request) based on the input query.
• FastAPI Endpoint: Exposes the agent functionality over a FastAPI endpoint for easy interaction.

Setup Instructions

1. Clone the Repository: bash git clone https://github.com/your-username/langchain-fastapi-agent.git cd langchain-fastapi-agent

2. Download the Northwind Database: sh curl -L -o northwind.db https://github.com/jpwhite3/northwind-SQLite3/blob/main/dist/northwind.db?raw=true

3. Install Dependencies: bash pip install fastapi uvicorn requests pydantic

4. Run the FastAPI Server: bash uvicorn agent_api:app --reload

5. Test the API with Postman:

   • Open Postman and create a new POST request to http://127.0.0.1:8000/query.

   • Set the request body to raw and JSON, for example: json { "query": "SELECT * FROM Customers" }

   • Send the request and view the response.

Endpoints

• POST /query: Accepts a JSON payload with a query string. Determines whether to query the database or fetch data from a public API based on the input query.

Example Queries

• Database Query: json { "query": "SELECT * FROM Customers" }

• Public API Query: json { "query": "Fetch data from public API" }

• Authenticated API Query: json { "query": "Fetch data from auth API" }

Deployment

The application can be deployed to cloud platforms like Render or Vercel for wider accessibility.

Demo

A demo video of the project interaction using Postman is available here.

License

This project is licensed under the MIT License. See the LICENSE file for more details.