MCP Simple Demo

A simple demonstration of the Model Context Protocol (MCP) with a Python server and client.

Overview

This project demonstrates a basic implementation of the Model Context Protocol (MCP), which allows AI models to access external tools and data sources. It includes:

• An MCP-compliant server with simple tools
• A client for interacting with the server
• Examples of tool calls and responses

Repository

The official repository for this project is available at: https://github.com/arjunprabhulal/mcp-simple-demo

Installation

Prerequisites

• Python 3.8+
• pip

Setup

1. Clone the repository:

git clone https://github.com/arjunprabhulal/mcp-simple-demo.git
cd mcp-simple-demo

2. Install the required packages:

# Using requirements.txt (recommended)
pip install -r requirements.txt

# Or install packages manually
pip install mcp llama-index llama-index-tools-mcp requests

Server Usage

The server provides MCP-compliant tools that can be accessed by AI models or client applications.

Starting the Server

python server.py

This starts an MCP server on the default port (8000) with two tools:

• hello_world: Returns a greeting message
• add: Adds two numbers

Debugging

To enable debugging logs:

DEBUG_LEVEL=DEBUG python server.py

For full debug mode:

DEBUG=true DEBUG_LEVEL=DEBUG python server.py

Client Usage

The provided client can interact with the MCP server in both interactive and command-line modes.

Interactive Mode

python client.py

This starts an interactive session where you can choose commands to execute.

Command Line Mode

List available tools:

python client.py tools

Call the hello_world tool:

python client.py hello
python client.py hello "Your Name"

Call the add tool:

python client.py add 5 3

Available Tools

hello_world

Returns a greeting message.

Parameters:

• name (optional): The name to greet (default: "World")

Returns:

• A JSON object with a message field: {"message": "Hello, Name!"}

add

Adds two numbers.

Parameters:

• a: First number (integer)
• b: Second number (integer)

Returns:

• The sum of a and b (integer)

Protocol Details

The Model Context Protocol (MCP) uses Server-Sent Events (SSE) for establishing connections. The flow works as follows:

1. Client connects to the /sse endpoint
2. Server returns a session ID
3. Client uses the session ID to make tool calls via /messages/?session_id=...

Advanced Testing

For more detailed testing of the server, use the test client:

python test_client.py

This performs more comprehensive tests of the MCP connection and available tools.

Contributions

Contributions to this project are welcome! Please feel free to submit issues or pull requests to the GitHub repository.

References

• Model Context Protocol Specification
• MCP Python SDK
• LlamaIndex MCP Integration
• MCP Simple Demo Repository