Fact Checker MCP Server

This is a Model Context Protocol (MCP) server that verifies simple factual claims by checking them against knowledge sources like Wikidata.

Features

• Accepts claims in natural language

• Verifies the accuracy of the claim

• Returns an MCP-compliant response with the claim, correct answer, and confidence score

• Includes an MCP client that integrates with Ollama LLM

Related MCP server: Groundcheck

MCP Payload Format

{
  "version": "1.0",
  "context": {
    "type": "fact_check",
    "claim": "The capital of France is London",
    "correct_answer": "Incorrect. The capital of France is Paris, not London.",
    "confidence": 0.95
  }
}

Setup and Installation

1. Clone this repository

2. Install dependencies:

   pip install -r requirements.txt

3. Run the server:

   python app.py

Usage

Server API

Send a POST request to the /fact-check endpoint with a JSON payload containing the claim:

curl -X POST http://localhost:5000/fact-check \
  -H "Content-Type: application/json" \
  -d '{"claim": "The capital of France is London"}'

MCP Client with Ollama Integration

The project includes an MCP client that demonstrates integration with Ollama LLM:

1. Make sure Ollama is installed and running:

   ollama serve

2. Run the demo script:

   bash run_demo.sh

3. Or run the client directly:

   python mcp_client.py --model llama3

The client will:

• Detect factual claims about capitals in your prompts

• Verify these claims using the MCP server

• Augment the LLM's knowledge with accurate information

• Ensure the LLM provides factually correct responses

Testing

Basic Testing

Run the test client with a specific claim:

python test_client.py "The capital of France is Paris"

Or run the default test suite with multiple claims:

python test_client.py

Comprehensive Test Suite

Run the comprehensive test suite that includes both correct and incorrect claims:

python test_client.py --test-suite

Unit Tests

Run the unit tests to verify the server's functionality:

python -m unittest test_unit.py

Supported Claim Types

Currently, the server can verify:

• Capital city claims (e.g., "The capital of [Country] is [City]")

More claim types will be added in future updates.

Extending the Server

To add support for new types of claims:

1. Add a new pattern matching regex in the check_fact() function

2. Implement a corresponding verification function similar to check_capital_claim()

License

MIT

Author

© Anthony Lim