MCP Calculator Server

This project is a simple Model Context Protocol (MCP) server that evaluates mathematical expressions sent by MCP clients. It can be used with the official MCP Python client or the VSCode MCP extension.

Features

• Evaluate math expressions using Python's math module (e.g., sqrt(25) + 2**3).

• Secure evaluation: only math functions/constants are available.

• Exposes a calculate tool via the MCP protocol.

• Compatible with the Model Context Protocol VSCode extension.

Related MCP server: MCP Server

Setup

1. Clone the repository and enter the directory:

   git clone <your-repo-url>
   cd calculator-mcp

2. Create and activate a virtual environment (recommended):

   python3 -m venv venv
   source venv/bin/activate

3. Install dependencies:

   pip install -r requirements.txt

Running the MCP Server

Start the server (by default, it listens on all interfaces at port 8500, root path):

python app.py

You should see:

MCP server running on 0.0.0.0:8500 (root path)

Using the Python Client

The provided client.py can be used to test the server:

python client.py

This will send the expression sqrt(25) + 2**3 to the server and print the result.

You can modify client.py to send other expressions.

Using the MCP Server in VSCode

1. Install the MCP Extension:

   • Open VSCode.

   • Go to Extensions (Ctrl+Shift+X or Cmd+Shift+X).

   • Search for Model Context Protocol or MCP and install the official extension.

2. Start the MCP server:

   • Make sure python app.py is running.

3. Connect VSCode to the MCP Server:

   • Open the Command Palette (Ctrl+Shift+P or Cmd+Shift+P).

   • Type MCP: Add Server or MCP: Connect to Server.

   • Enter the server URL:

     http://127.0.0.1:8500/

   • Give it a name (e.g., "Calculator MCP").

4. Use the MCP Tools in VSCode:

   • Open the MCP sidebar (look for the MCP icon).

   • Select your server.

   • You should see the calculate tool.

   • Run the tool, enter a math expression, and see the result in VSCode.

Security Note

• Only math functions/constants are available to evaluated expressions.

• No access to Python built-ins or the file system.

License

MIT