MCP Inspector

MCP Inspector is an interactive developer tool for testing and debugging Model Context Protocol (MCP) servers. It provides a user-friendly interface to inspect server capabilities, test functionality, and diagnose issues.

Overview

The MCP Inspector tool allows developers to connect to any MCP server and interactively explore its features, including resources, prompts, and tools. It runs directly via npx without requiring installation and supports inspection of servers from NPM, PyPi, and local development environments.

Key Features

  • Server Connection Pane: Configure and connect to MCP servers
  • Resources Tab: Explore available resources and test subscriptions
  • Prompts Tab: Test prompt templates with custom arguments
  • Tools Tab: Explore and test server tools with custom inputs
  • Notifications Pane: View server logs and notifications
  • Debugging Features: Diagnose connectivity and protocol issues

Getting Started

To use the MCP Inspector with your server, you can run it directly using npx. The tool will connect to your server and provide an interactive interface for exploring its capabilities.

Running MCP Inspector with an NPM package server
# Basic usage with an NPM package server
npx @modelcontextprotocol/inspector npx server-postgres postgres://127.0.0.1/testdb

# Running with a local TypeScript server

npx @modelcontextprotocol/inspector node path/to/server/index.js

# Running with a Python server

npx @modelcontextprotocol/inspector python -m myserver

# Running with the Candidate MCP server from this project

npx @modelcontextprotocol/inspector npx @jhgaylor/candidate-mcp-server

Usage with MaiTai Profile Server

To inspect your MaiTai professional profile MCP server, you can connect the inspector directly to your server endpoint.

Inspecting Your MaiTai Profile Server
# Connect to your profile server using the inspector
npx @modelcontextprotocol/inspector https://maitai.io/u/your-username/mcp

# Or if using Server-Sent Events transport

npx @modelcontextprotocol/inspector https://maitai.io/u/your-username/sse

Interface Overview

The MCP Inspector provides several key interfaces for testing your server:

Server Connection Pane

The left sidebar allows you to:

  • Configure server connection parameters
  • Select transport protocols (stdio, SSE, HTTP)
  • Include additional environment variables
  • Manage connection and disconnection

Resources Tab

Explore and interact with server resources:

  • View available resources and their URIs
  • Read resource contents
  • Test resource subscriptions
  • Monitor resource updates

Prompts Tab

Test and debug prompt templates:

  • View all available prompts
  • Set custom argument values
  • Preview generated messages
  • Test prompt functionality

Tools Tab

Interact with server tools:

  • List all available tools
  • View tool descriptions and parameters
  • Execute tools with custom inputs
  • Inspect tool responses

Notifications Pane

Monitor server activity:

  • View progress notifications
  • Track resource updates
  • Debug logging events
  • Monitor error messages

Testing Your Server

When connecting to your MaiTai profile server, the inspector allows you to:

Test Resource Access

Check that your professional information is properly exposed through resources:

/resume - Your resume content
/skills - Your skills and expertise
/portfolio - Your portfolio items
/contact - Your contact information

Test Prompts

Verify that prompts are generating appropriate messages:

generate-cover-letter - Test cover letter generation
analyze-resume - Test resume analysis
mock-interview - Test interview preparation

Test Tools

Validate that tools are functioning correctly:

search-profile - Search professional information
format-section - Format different profile sections
schedule-meeting - Test calendar integration

Debugging Common Issues

Connection Failures

  • Verify your server URL is correct
  • Check that the transport type matches your server configuration (SSE for MaiTai)
  • Ensure your server is running and accessible
  • Look for authentication errors in the notifications pane

Resource Access Problems

  • Confirm resources are properly registered in your server
  • Check for permissions or authentication issues
  • Monitor the notifications pane for error messages

Tool Execution Errors

  • Verify that tool parameters are correctly formatted
  • Check for missing required arguments
  • Monitor server logs for detailed error messages

Tip: The MCP Inspector is an invaluable tool for development and troubleshooting. Use it regularly to ensure your server is functioning correctly before connecting to AI assistants.

Next Steps