Fact Checker

A command-line fact-checking assistant that uses LLMs and web search to verify user claims. Built with LangGraph, and Tavily Search.

Features

• Accepts user claims interactively via the terminal
• Searches the web for evidence using Tavily
• Uses a Google Gemini LLM to compare the claim against evidence
• Returns a verdict: TRUE, FALSE, or PARTIALLY TRUE, with detailed explanation and sources

Setup

1. Clone the repository
2. Install dependencies

   pip install -r requirements.txt

3. Set up API keys
   • Create a .env file in the project root with the following:

     GOOGLE_API_KEY="<your-google-api-key>"
     TAVILY_API_KEY="<your-tavily-api-key>"

Usage

Run the fact checker from the terminal:

python3 fact_checker.py

Enter a claim when prompted. The assistant will search for evidence and return a verdict with sources.

Type quit or exit to stop.

Requirements

• Python 3.8+
• langchain
• langgraph
• langchain-tavily
• python-dotenv

License

MIT