Hmr MCP Server

Hot-reload monitor for MCP servers - like nodemon but for Model Context Protocol

Local serverstdioPython

What is the Hmr MCP server?

Hmr MCP server exists for a simple reason — assistants are far more useful when they can act on Hmr directly instead of describing what you should do. Hot-reload monitor for MCP servers - like nodemon but for Model Context Protocol.

What you get

Make changes to your MCP server code and see them instantly without restarting your MCP client. Just like nodemon automatically restarts Node.js applications, mcpmon automatically restarts MCP servers.

Setting it up

Installation goes through your MCP client rather than a global install: point it at @modelcontextprotocol/inspector on npm and it is fetched when the client starts. The copy-paste blocks for Claude Desktop, Claude Code and Cursor are further down this page.

Configuration and credentials

You will need 2 environment variables: API_KEY, PYTHONPATH. The server will not start without them, which is usually why the tools fail to appear on a first run. Keep credentials in your client's env block or a secrets manager rather than in a file you might commit.

Before you rely on it

  • It runs with your machine's permissions. That is convenient and also the reason to think about what you point it at before you approve a tool call.
  • Missing credentials fail quietly in some clients — if no tools show up, check the environment block first.
  • MCP clients confirm each tool call by default. Leave that on until you have watched what the hmr mcp server does with a few real requests.

Choosing this one

Among the developer tooling options, the useful question is rarely "what can it do" but "what does it cost you to run" — permissions, credentials, and how much of your context its toolset consumes. It is maintained by neilopet; worth a glance at recent repository activity before you build anything load-bearing on it.

SyncDev reviews every entry in this directory against the project's own documentation before publishing, and revisits them as servers change.

How to install the Hmr MCP server

{
  "mcpServers": {
    "server-hmr": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/inspector"],
      "env": {
        "API_KEY": "your-value",
        "PYTHONPATH": "your-value"
      }
    }
  }
}

Add to claude_desktop_config.json, then restart Claude Desktop.

Configuration

VariableDescriptionRequired
API_KEYCredential the server authenticates with.Yes
PYTHONPATHFilesystem location the server is allowed to use.Optional

Frequently asked questions

It connects Hmr to MCP-compatible AI assistants such as Claude and Cursor. Instead of copying data back and forth by hand, the assistant works with Hmr directly.