My MCP Project

A simple Model Context Protocol (MCP) proof-of-concept that exposes calculator tools through an MCP server and connects to them from a LangChain-powered client using Groq.

Quick Start

git clone <your-repo-url>
cd my-mcp-project
python -m venv .venv
.venv\Scripts\activate
pip install -e .

Create a .env file:

GROQ_API_KEY=your_groq_api_key_here
GROQ_MODEL=openai/gpt-oss-20b

Start the server:

python server.py

In a second terminal, run the client:

python client.py

Then ask questions like:

You: What is 12 + 18?
Assistant: 30

This project demonstrates how to:

• Start an MCP server with tools such as add, subtract, multiply, and divide

• Expose those tools over HTTP using streamable-http

• Connect a client to the MCP server

• Use a Groq LLM to call MCP tools dynamically from natural-language prompts

Related MCP server: MathServer

Project Structure

• server.py – MCP server that exposes calculator tools

• client.py – client that connects to the server and uses a Groq model

• pyproject.toml – project metadata and Python dependencies

• .env – local environment file for your Groq API key

Requirements

Before you run the project, make sure you have:

• Python 3.13 or newer

• A Groq account and API key

• Git installed

Clone the Repository

git clone <your-repo-url>
cd my-mcp-project

Set Up a Virtual Environment

From the project root:

python -m venv .venv

On Windows:

.venv\Scripts\activate

On macOS/Linux:

source .venv/bin/activate

Install Dependencies

This project uses pyproject.toml, so install the package and dependencies like this:

pip install -e .

If you want to verify the installation afterwards:

python -c "import mcp, langchain_groq; print('Dependencies ready')"

Configure Environment Variables

Create a .env file in the root folder with the following values:

GROQ_API_KEY=your_groq_api_key_here
GROQ_MODEL=openai/gpt-oss-20b

Notes:

• GROQ_API_KEY is required for the client to work.

• GROQ_MODEL is optional; if omitted, the app falls back to openai/gpt-oss-20b.

Run the MCP Server

Open a terminal in the project folder and run:

python server.py

You should see output similar to:

[MCP SERVER] Starting on http://127.0.0.1:8001/mcp

This starts the MCP server and exposes the tools on:

http://127.0.0.1:8001/mcp

Run the Client

Open a second terminal, activate the virtual environment if needed, and run:

python client.py

The client will:

• read the Groq key from .env

• connect to the MCP server

• list available tools

• start an interactive chat session

Example interaction:

You: What is 12 + 18?
Assistant: 30

You can also ask things like:

• "Multiply 7 by 9"

• "Divide 20 by 4"

• "Subtract 50 from 120"

Type exit to quit the client.

Example Tools Exposed by the Server

The server exposes these tools:

• add(a, b)

• subtract(a, b)

• multiply(a, b)

• divide(a, b)

• validate_call(token, message)

Troubleshooting

1. GROQ_API_KEY is missing

Make sure your .env file exists and contains the correct key.

2. Server does not start

Check whether port 8001 is free and whether you are running the server from the project root.

3. Client cannot connect to the server

Ensure the MCP server is already running before starting the client.

4. Module not found errors

Reinstall dependencies:

pip install -e .

Notes

This project is a simple MCP proof-of-concept intended for learning and experimentation. It is useful for understanding how to:

• build tool-calling MCP servers

• connect a client to an MCP endpoint

• integrate MCP tools with LangChain and Groq

Screenshots

These sample images show the expected project behavior:

Server startup

Client interaction

License

This project is licensed under the MIT License.

Contributing

Contributions are welcome. Please see CONTRIBUTING.md for development and pull request guidelines.