---
title: MCP Inspector — MCP protocol
date: 2026-10-18
time: 12:00
model: admin
category: programs
author_type: human
summary: Web UI for testing and debugging MCP servers that supports stdio, SSE, and Streamable HTTP transports.
tags: program, MCP protocol, inspector
---

Official developer tool for testing and debugging MCP servers

## Basic Information

| Program Name | MCP Inspector (MCP Inspector) |
| --- | --- |
| One-line Introduction | Official developer tool for testing and debugging MCP servers |
| Development & Maintenance | Model Context Protocol project |
| Official Website | https://modelcontextprotocol.io/docs/tools/inspector |
| Official Documentation | https://modelcontextprotocol.io/docs/tools/inspector |
| Installation & Distribution | npx @modelcontextprotocol/inspector |
| Runtime Environment | Node.js 18+ · web browser |
| License | MIT License |
| Stable Version | 2.11.0 (npm, confirmed 2026-10) — confirmed on 2026-10-18 |
| GitHub Repository | https://github.com/modelcontextprotocol/inspector |
| Category | MCP protocol (tags: MCP, debugging, testing, protocol, developer tools) |

## What Is This Program?

MCP Inspector is the official developer tool for testing and debugging MCP (Model Context Protocol) servers. It consists of a React-based web UI and a Node.js proxy, and contains three clients in a single package (@modelcontextprotocol/inspector).

You can visually inspect the tools, resources, and prompts exposed by a server and view request and response messages in real time. It is the first tool to launch when building an MCP server or connecting to an existing one.

## What Problems Does It Solve?

- When you need to verify that a newly built MCP server works correctly
- When you need to find the cause of MCP server connection failures from a client
- When you need to compare different transport methods such as stdio and HTTP in the same environment
## Key Features

### Web UI

Visually browse tools, resources, and prompts in the browser

- **When to Use**: Get an overview of server capabilities at a glance
- **What You Get**: Invoke tools and check results without typing
- **Limitations**: Large responses may require scrolling
### Multi-Transport Support

Supports stdio, SSE, and Streamable HTTP transports

- **When to Use**: Debugging all types of MCP servers
- **What You Get**: Compare behavior across transport methods
- **Limitations**: Authentication settings differ slightly by transport
### Real-Time Monitoring

Displays protocol traffic in the sidebar in real time

- **When to Use**: Trace request and response flows
- **What You Get**: Detailed logs for debugging
- **Limitations**: Filtering is needed when there are many logs
### Export Configuration

Export the server launch configuration to mcp.json

- **When to Use**: Share client configurations
- **What You Get**: A reproducible debugging environment setup
- **Limitations**: Check for format differences between clients
## Installation and Execution

### npx (Recommended)

Runs immediately with npx without separate installation.

```
npx @modelcontextprotocol/inspector
```

### npm Global Installation

If you use it frequently, install it globally.

```
npm install -g @modelcontextprotocol/inspector
```

### Docker

Run it in an isolated container.

```
docker run -p 5173:5173 -p 8080:8080 mcp/inspector
```

## Practical Usage Examples

### Connecting to a Server

Run Inspector and enter the MCP server command to connect.

```
npx @modelcontextprotocol/inspector npx -y @modelcontextprotocol/server-filesystem /tmp
```

### Invoking a Tool

On the Tools tab, select a tool, enter its arguments, and run it.

```
Example: enter a path in the read_file tool and click Run
```

### Reviewing Traffic

Check request and response messages in the Monitoring sidebar.

```
Check STDIO · SSE · HTTP logs in real time
```

## Advantages and Limitations

### Advantages

- A highly reliable tool maintained by the official MCP project
- Supports stdio, SSE, and HTTP transports in a single UI
- Runs immediately with npx without separate installation
- Visually traces request and response traffic
### Considerations Before Use

- Debugging the server-side logic itself requires a separate tool
- Browsing large tool lists can be somewhat slow
- OAuth authentication flows require additional setup
## Comparison with Similar Programs

| Program | Characteristics | Best For |
| --- | --- | --- |
| curl·Postman | Test with direct HTTP requests | Testing general APIs other than MCP |
| Claude Desktop logs | Check host app-side connection logs | Tracing client integration issues |
| mcp-use debugger | Built-in debugging for the Python framework | Projects based on mcp-use |

## Official Resources and Further Learning

- [Official Homepage](https://modelcontextprotocol.io/docs/tools/inspector) — https://modelcontextprotocol.io/docs/tools/inspector
- [Official Documentation / Knowledge Base](https://modelcontextprotocol.io/docs/tools/inspector) — https://modelcontextprotocol.io/docs/tools/inspector
- [Installation & Distribution](npx @modelcontextprotocol/inspector) — npx @modelcontextprotocol/inspector
- [Release Notes](https://github.com/modelcontextprotocol/inspector/releases) — https://github.com/modelcontextprotocol/inspector/releases
- [Source / Development Materials](https://github.com/modelcontextprotocol/inspector) — https://github.com/modelcontextprotocol/inspector
Version and supported environment information was confirmed on the official site as of 2026-10-18. Installation commands may vary depending on your distribution and version, so please also check the official installation documentation.

## Actual Execution Screenshot

Synthetic example — not an actual execution result. The screenshot is a synthetic example and is not an actual execution result.

![Example MCP Inspector execution screen](https://games.aidebatehub.com/assets/inspector-demo.png)

A server in actual operation

---
Source (HTML): https://games.aidebatehub.com/programs/mcp/protocol/inspector.html
This file is an auto-generated Markdown twin of the DevHub document.