Spec3 MCP Server
A Model Context Protocol (MCP) server built with FastMCP for local development and testing with Claude Desktop on WSL.
Overview
This MCP server provides a set of tools and utilities that can be used by Claude Desktop through the MCP protocol. It's designed to run locally on your WSL machine and connect to Claude Desktop via stdio.
Features
- Modern Python Project Structure: Uses - pyproject.tomland follows Python packaging best practices
- FastMCP Integration: Built on the FastMCP framework for easy MCP protocol handling 
- Multiple Tools: Includes basic demonstration and utility tools 
- Comprehensive Logging: Detailed logging for debugging and monitoring 
- Type Hints: Full type annotation support for better development experience 
- WSL Compatible: Runs seamlessly on WSL and connects to Claude Desktop 
Available Tools
- hello_world: Returns a simple greeting message 
- echo_message: Echoes back a message with additional formatting 
- get_server_info: Returns comprehensive server information and capabilities 
- list_available_tools: Lists all available tools with descriptions 
Installation
Prerequisites
- Python 3.10 or higher 
- WSL (Windows Subsystem for Linux) 
- Claude Desktop (installed on Windows) 
Setup
- Navigate to the project directory: cd /home/dhevb/workspaces/spec3-mcp-server
- Create and activate a virtual environment: python -m venv venv source venv/bin/activate
- Install the package in development mode: pip install -e .- This will install the package and all its dependencies, including FastMCP. 
- Verify the installation: spec3-mcp-server --help
Connecting to Claude Desktop
Configure Claude Desktop on Windows
- Locate your Claude Desktop config file: - On Windows, it's typically at: - %APPDATA%\Claude\claude_desktop_config.json
- Full path is usually: - C:\Users\YourUsername\AppData\Roaming\Claude\claude_desktop_config.json
 
- Edit the configuration file and add the following: { "mcpServers": { "spec3-mcp-server": { "command": "wsl", "args": [ "-e", "/home/dhevb/workspaces/spec3-mcp-server/venv/bin/python", "/home/dhevb/workspaces/spec3-mcp-server/src/spec3_mcp_server/main.py" ], "env": {} } } }- Note: The - wslcommand allows Claude Desktop on Windows to execute Python in your WSL environment.
- Restart Claude Desktop to load the new configuration 
- Verify the connection: - Open Claude Desktop 
- Start a new conversation 
- Look for the MCP tools icon or hammer icon 
- You should see the spec3-mcp-server tools available 
 
Alternative: Using Installed Command
If you prefer to use the installed spec3-mcp-server command:
Testing the Server
Test Locally (Without Claude Desktop)
You can test the server locally to ensure it's working:
The server will start and wait for MCP messages on stdin. You can verify it's running if you see the startup logs.
Test with Claude Desktop
Once connected to Claude Desktop, you can test the tools by asking Claude to use them:
- "Use the hello_world tool" 
- "Echo this message: Hello from WSL!" 
- "Get server information" 
- "List all available tools" 
Development
Project Structure
Adding New Tools
To add new tools to the MCP server:
- Edit 
- Add a new tool function decorated with 
- Add proper type hints and docstring 
Example:
- Reinstall the package (if needed): pip install -e .
- Restart Claude Desktop to load the updated tools 
Code Quality
The project includes configuration for:
- Black: Code formatting 
- isort: Import sorting 
- mypy: Type checking 
- ruff: Linting 
- pytest: Testing 
Run quality checks:
Troubleshooting
Common Issues
- Server won't start: - Check that Python 3.10+ is installed in WSL: - python --version
- Ensure FastMCP is installed: - pip install fastmcp
- Verify virtual environment is activated: - which python
 
- Claude Desktop can't connect: - Verify the paths in - claude_desktop_config.jsonare correct
- Check that WSL is accessible from Windows 
- Look at Claude Desktop's logs for connection errors 
- Test the server manually in WSL first 
 
- Tools not appearing: - Restart Claude Desktop after configuration changes 
- Check server logs for errors 
- Verify the server is running: - ps aux | grep spec3-mcp-server
 
- WSL-specific issues: - Ensure WSL is properly installed: - wsl --version
- Test WSL execution from Windows CMD: - wsl -e python --version
- Check WSL distro is running: - wsl -l -v
 
Logging
The server includes comprehensive logging. Check the console output for:
- Server startup messages 
- Tool execution logs 
- Error messages and stack traces 
To see logs when running via Claude Desktop, you can redirect them to a file by modifying the config:
Getting Help
If you encounter issues:
- Check the server logs for error messages 
- Verify your Python and FastMCP versions 
- Test the server independently before connecting to Claude Desktop 
- Check the FastMCP documentation at https://github.com/jlowin/fastmcp 
- Review Claude Desktop's documentation for MCP configuration 
Next Steps
Once you have the local server working:
- Add more sophisticated tools for your specific use cases 
- Implement error handling for robust operation 
- Add tests to ensure reliability 
- Explore advanced MCP features like resources and prompts 
- Consider adding environment variables for configuration 
License
MIT License - see LICENSE file for details.
local-only server
The server can only run on the client's local machine because it depends on local resources.
A demonstration MCP server for local development and testing with Claude Desktop on WSL. Provides basic utility tools including greeting messages, echo functionality, and server information retrieval.