MCP Inspector VSCode Extension: Real-Time Debugging & UI Optimization

Key Features of MCP Inspector VSCode Extension: Real-Time Debugging & UI Optimization

• Visual Debugging Hub: Centralized dashboard displaying request/response timelines and server metrics with interactive graphs.
• Smart Automation: Auto-port selection prevents conflicts, while background dependency installation reduces setup friction.
• Test Request Builder: Pre-configured templates and parameter editors simplify crafting complex MCP protocol queries.
• Performance Insights: Real-time latency tracking and error highlighting pinpoint bottlenecks during server interactions.
• One-Click Server Control: Start/stop commands with status indicators ensure precise lifecycle management.

Use cases of MCP Inspector VSCode Extension: Real-Time Debugging & UI Optimization

Developers benefit from this extension in scenarios such as:

• API Validation: Testing edge cases in MCP server responses under varying input conditions.
• Performance Tuning: Identifying lag points by comparing request/response timing metrics.
• Collaborative Debugging
: Sharing snapshot reports of server interactions for team troubleshooting.
• CI/CD Integration
: Automating test suites through the extension’s command-line interface for continuous validation.
• Legacy Code Audits
: Tracing historical request patterns to diagnose compatibility issues with older MCP versions.

FAQ from MCP Inspector VSCode Extension: Real-Time Debugging & UI Optimization

Why does the server fail to start initially?

Run the "Clean NPM Cache" command and ensure Node.js v18+ is installed. Check firewall settings if port 3000 is blocked.

Can I customize the UI layout?

While the core interface is fixed, you can adjust display preferences via the settings schema to hide/show metrics panels.

Does it support multiple server instances?

Currently limited to single-server debugging, but multi-instance support is planned for future updates.

How do I contribute improvements?

Fork the GitHub repository, make changes, and submit a pull request through the contribution workflow.

What’s the best way to report an issue?

Include a screenshot of the error and output channel logs when creating an issue ticket on our GitHub tracker.

MCP Inspector VSCode Extension

中文文档

MCP Inspector is a VSCode extension designed for visual testing and debugging of MCP (Model Control Protocol) servers. This extension provides a user-friendly interface to help developers test, debug, and monitor MCP server behavior more efficiently.

The WebView UI part of this extension is based on the Model Context Protocol Inspector project, which is the official debugging and testing tool for the Model Context Protocol.

Features

• Visual Interface : Display MCP server requests and responses through an intuitive WebView interface
• Real-time Monitoring : Monitor MCP server activities and status in real-time
• Request Testing : Provide an interface for building and sending test requests to MCP servers
• Response Analysis : Format and display response data for easy analysis and debugging
• Server Management : Built-in server management functions to start and stop MCP servers directly from VSCode
• Automatic Port Allocation : Automatically find available ports to avoid port conflicts

Requirements

• Visual Studio Code 1.97.0 or higher
• Node.js and npm (for running the built-in server)

Installation

1. Install from the VSCode Extension Marketplace, or
2. Download the .vsix file and install via VSCode's "Install from VSIX..." option, or
3. Clone the repository and build manually:

git clone https://github.com/kshern/mcp-inspector-vsocde.git
cd mcp-inspector-vsocde
npm install
npm run package

Usage

1. Click the MCP Inspector icon in the VSCode activity bar to open the extension
2. Click the "Start MCP Inspector Server" command to start the server
3. Use the WebView interface to build and send requests to the MCP server
4. Analyze response results and server behavior
5. When finished, click the "Stop MCP Inspector Server" command to stop the server

Available Commands

• MCP Inspector: Open MCP Inspector - Open the main interface
• MCP Inspector: Start MCP Inspector Server - Start the proxy server
• MCP Inspector: Stop MCP Inspector Server - Stop the proxy server
• MCP Inspector: Clean NPM Cache and Dependencies - Clean npm cache and dependencies when installation issues occur

Extension Settings

This extension contributes the following settings:

• mcp-inspector.serverPort: Port number used by the MCP Inspector server (default: 3000). If unavailable, it will automatically find another port.
• mcp-inspector.autoStartServer: Whether to automatically start the MCP Inspector server when the extension activates (default: true).
• mcp-inspector.installDependencies: Whether to automatically install missing dependencies when starting the server for the first time (default: true).
• mcp-inspector.preInitializeOnActivation: Whether to automatically install dependencies and build the server in the background when the extension activates (default: true). This speeds up the first server start.
• mcp-inspector.serverStartTimeout: Server startup timeout in milliseconds (default: 30000).

Troubleshooting

If you encounter issues with the server not starting:

1. Try using the "Clean NPM Cache and Dependencies" command from the command palette
2. Check the MCP Inspector output channel for detailed error messages
3. Ensure Node.js and npm are properly installed and accessible
4. If permission issues occur, try running VSCode with administrator privileges

Project Structure

mcp-inspector-vsocde/
├── src/                 # Extension source code
├── webview-ui/          # WebView UI code (based on github.com/modelcontextprotocol/inspector)
│   ├── client/          # Frontend client code
│   └── server/          # Proxy server code
├── resources/           # Resource files
└── dist/                # Compiled code

Technical Implementation

This extension consists of two parts:

1. VSCode Extension Part : Responsible for creating WebViews in VSCode, managing server processes, and handling user interface interactions
2. WebView UI Part : Based on the Model Context Protocol Inspector project, providing an intuitive user interface for testing and debugging MCP servers

By integrating the official MCP Inspector tool into VSCode, this extension provides developers with a more convenient experience for MCP server development and testing.

Development Guide

Build and Debug

1. Clone the repository
2. Install dependencies: npm install
3. Open the project in VSCode
4. Press F5 to start a debugging session

Build the Extension

npm run package

This will generate compiled code in the dist directory.

Contributing

Contributions of code, issue reports, or improvement suggestions are welcome. Please follow these steps:

1. Fork the repository
2. Create a feature branch: git checkout -b feature/your-feature-name
3. Commit your changes: git commit -m 'Add some feature'
4. Push to the branch: git push origin feature/your-feature-name
5. Submit a Pull Request

Acknowledgements

Special thanks to the Model Context Protocol team for developing the MCP Inspector project, which the WebView UI part of this extension is based on.

Known Issues

• In some environments, the server may need to be manually restarted to work properly
• Multiple MCP server debugging is not currently supported

Release Notes

0.0.1

• Initial release
• Basic MCP server testing functionality
• WebView UI interface
• Server start and stop functionality

License

MIT

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Enjoy using MCP Inspector!