MCP Calculator Server
A simple Model Context Protocol server that evaluates mathematical expressions like 'sqrt(25) + 2**3' sent by MCP clients, with secure evaluation that only allows math functions/constants.
README Documentation
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
mathmodule (e.g.,sqrt(25) + 2**3). - Secure evaluation: only math functions/constants are available.
- Exposes a
calculatetool via the MCP protocol. - Compatible with the Model Context Protocol VSCode extension.
Setup
-
Clone the repository and enter the directory:
git clone <your-repo-url> cd calculator-mcp -
Create and activate a virtual environment (recommended):
python3 -m venv venv source venv/bin/activate -
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
-
Install the MCP Extension:
- Open VSCode.
- Go to Extensions (
Ctrl+Shift+XorCmd+Shift+X). - Search for
Model Context ProtocolorMCPand install the official extension.
-
Start the MCP server:
- Make sure
python app.pyis running.
- Make sure
-
Connect VSCode to the MCP Server:
- Open the Command Palette (
Ctrl+Shift+PorCmd+Shift+P). - Type
MCP: Add ServerorMCP: Connect to Server. - Enter the server URL:
http://127.0.0.1:8500/ - Give it a name (e.g., "Calculator MCP").
- Open the Command Palette (
-
Use the MCP Tools in VSCode:
- Open the MCP sidebar (look for the MCP icon).
- Select your server.
- You should see the
calculatetool. - 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