Model Context Protocol(MCP)
  1. Tutorials
Model Context Protocol(MCP)
  • Get Started
    • Introduction
    • Example Servers
    • Example Clients
    • Quickstart
      • For Server Developers
      • For Client Developers
      • For Claude Desktop Users
  • Tutorials
    • Building MCP with LLMs
    • Debugging
    • Inspector
  • Concepts
    • Core architecture
    • Resources
    • Prompts
    • Tools
    • Sampling
    • Roots
    • Transports
  • Development
    • What's New
    • Roadmap
    • Contributing
  1. Tutorials

Inspector

In-depth guide to using the MCP Inspector for testing and debugging Model Context Protocol servers
The MCP Inspector is an interactive developer tool for testing and debugging MCP servers. While the Debugging Guide covers the Inspector as part of the overall debugging toolkit, this document provides a detailed exploration of the Inspector’s features and capabilities.

Getting started#

Installation and basic usage#

The Inspector runs directly through npx without requiring installation:

Inspecting servers from NPM or PyPi#

A common way to start server packages from NPM or PyPi.
NPM package
PyPi package

Inspecting locally developed servers#

To inspect servers locally developed or downloaded as a repository, the most common way is:
TypeScript
Python
Please carefully read any attached README for the most accurate instructions.

Feature overview#

img
The MCP Inspector interface
The Inspector provides several features for interacting with your MCP server:

Server connection pane#

Allows selecting the transport for connecting to the server
For local servers, supports customizing the command-line arguments and environment

Resources tab#

Lists all available resources
Shows resource metadata (MIME types, descriptions)
Allows resource content inspection
Supports subscription testing

Prompts tab#

Displays available prompt templates
Shows prompt arguments and descriptions
Enables prompt testing with custom arguments
Previews generated messages

Tools tab#

Lists available tools
Shows tool schemas and descriptions
Enables tool testing with custom inputs
Displays tool execution results

Notifications pane#

Presents all logs recorded from the server
Shows notifications received from the server

Best practices#

Development workflow#

1.
Start Development
Launch Inspector with your server
Verify basic connectivity
Check capability negotiation
2.
Iterative testing
Make server changes
Rebuild the server
Reconnect the Inspector
Test affected features
Monitor messages
3.
Test edge cases
Invalid inputs
Missing prompt arguments
Concurrent operations
Verify error handling and error responses
Modified at 2025-03-12 06:54:01
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