hmr — Claude Code MCP server: Python HMR docs for your agent
An MCP server that serves the hmr docs — hot module reload and reactive programming for Python — so your agent stops guessing at the API.
claude mcp add --transport http hmr https://pyth-on-line.promplate.dev/hmr/mcpWhat hmr does
The server hands your agent the documentation for hmr, a reactive programming engine for Python and a hot-reload tool built on top of it. That covers the core library and the packages around it: uvicorn-hmr for ASGI apps, mcp-hmr for MCP servers, hmr-daemon for refreshing modules in the background.
It runs over HTTP, so there is nothing to install locally. In Claude the whole setup is claude mcp add --transport http hmr https://pyth-on-line.promplate.dev/hmr/mcp. Cursor and GitHub Copilot take a JSON block in their config, while Codex and Gemini CLI use their own mcp add command with the http transport type.
hmr itself tracks dependencies at runtime rather than by static analysis: change a variable and only the modules that depend on it rerun, with app state left intact. Circular dependencies can still misbehave in edge cases, and the author advises caution if your __init__.py holds a lot of code.
What it helps with
- look up hmr behaviour without reading the library source
- compare hmr against
uvicorn --reloadandwatchfiles - pick the right ecosystem package for an ASGI or MCP server
- wire Python library docs into an agent over HTTP
- understand how runtime dependency tracking works
Example prompts for the agent
- How does hmr track dependencies between modules at runtime?
- Show me how to run a FastAPI app with
uvicorn-hmr - What does hmr do differently from
uvicorn --reload?
How to install hmr
Platform CLI: remote server
claude mcp add --transport http hmr https://pyth-on-line.promplate.dev/hmr/mcpPlatform CLI: remote server
codex mcp add hmr --url https://pyth-on-line.promplate.dev/hmr/mcpConfig file
{
"mcpServers": {
"hmr": {
"url": "https://pyth-on-line.promplate.dev/hmr/mcp"
}
}
}Config file
{
"servers": {
"hmr": {
"type": "http",
"url": "https://pyth-on-line.promplate.dev/hmr/mcp"
}
}
}Platform CLI: remote server
gemini mcp add -t http hmr https://pyth-on-line.promplate.dev/hmr/mcpStep by step, with commands for each platform: How to add an MCP server to Claude Code, Codex, Cursor, VS Code, Gemini CLI and more
Questions about hmr
How do I install hmr in Claude Code?
Run claude mcp add --transport http hmr https://pyth-on-line.promplate.dev/hmr/mcp. The server connects over HTTP and needs no local package install.
What does hmr do?
It gives your agent the docs for hmr, a reactive programming engine and hot-reload tool for Python. Answers about the API come from the docs instead of guesswork.
Does hmr reload the browser when server code changes?
No. It is server-side HMR and only reloads Python code. Browser auto-refresh lives in a separate package, fastapi-reloader.
