The server inspector

Setup and Access

• Activate your Python environment (check the readme for exact command)
• Run mcp dev mcpserver. py in terminal to start the server
• Server listens on port 6277 and provides a browser address
• Open the address to access the MCP Inspector tool

MCP Inspector Overview

• Inspector is under active development, so UI may change over time
• Provides in-browser debugging without wiring to a real application
• Left sidebar has a Connect button to start your MCP server

Navigation and Testing

• Top menu bar shows available sections: resources, prompts, tools, etc.
• Click on Tools section to view all available tools
• Click "list tools" to see the tools you've created
• Select a tool to open its configuration panel on the right

Testing Individual Tools

• Use the right-hand panel to manually invoke tools
• Provide required parameters (e. g. , document IDs)
• Click "run tool" to execute and see results
• Verify output matches expected behavior

Workflow Example

• Test read operations first to confirm data retrieval
• Test write operations and verify changes by re-reading the data
• String matching is case-sensitive when testing
• Tools that modify data don't return contents—verify separately with read tools

Key Benefit

• Allows live development and debugging without integrating with external applications
• Essential tool for iterative MCP server development

Takeaways

• Use mcp dev mcpserver. py to start the server and access the MCP Inspector in your browser for in-browser debugging
• Navigate to the Tools section, list your tools, and select individual tools to view their configuration and test parameters
• Manually invoke tools using the right-hand panel, provide required parameters, and click "run tool" to verify output behavior
• Test read operations first, then write operations, and re-read data to confirm changes (since write tools don't return contents)
• The Inspector enables live development and iterative testing without integrating with external applications