# inspector

> MCP Server

The MCP Inspector is a developer tool for testing and debugging MCP servers, allowing users to inspect server implementations without cloning the repository. It includes a client UI and MCP proxy server.

## Overview

- **Category:** Developer Tools
- **Language:** TypeScript
- **Stars:** 10668
- **Forks:** 162
- **Owner:** modelcontextprotocol
- **GitHub:** https://github.com/modelcontextprotocol/inspector
- **Homepage:** https://modelcontextprotocol.io
- **Created:** 2024-10-03T21:47:42+00:00
- **Updated:** 2025-03-28T22:25:06+00:00
- **Source:** https://model-context-protocol.com/servers/mcp-server-visual-testing-inspector-tool

## Setup

## Setup

**From an MCP server repository:**

1.  Use `npx @modelcontextprotocol/inspector node build/index.js` to inspect an MCP server implementation.
2.  Pass arguments directly to your server.
3.  Set environment variables using the `-e` flag.
4.  Use `--` to separate inspector flags from server arguments.
5.  Customize the client UI (default port 5173) and MCP proxy server (default port 3000) ports using `CLIENT_PORT` and `SERVER_PORT`.

**From this repository:**

*Development mode:*

1.  `npm run dev`

> **Note for Windows users:**
> On Windows, use the following command instead:
>
> ```bash
> npm run dev:windows
> ```

*Production mode:*

1.  `npm run build`
2.  `npm start`

## Tools

## Available Tools

1.  **MCP Inspector:** A developer tool for testing and debugging MCP servers.
2.  **Client UI:** Allows interaction with the inspector (default port 5173).
3.  **MCP Proxy Server:** Communicates with local MCP processes (default port 3000).
4.  **Bearer Token Authentication:** Supports bearer token authentication for SSE connections.