mcp-hmr: AsyncReloader initialized with empty watch path, breaking hot reload

[verveguy]

Problem

mcp-hmr initializes reactivity.hmr.core.AsyncReloader with an empty watch path (""):

• packages/mcp-hmr/mcp_hmr.py: super().__init__("")

Depending on platform / watcher backend, watching "" results in:

• no files being watched (hot reload silently does nothing), or
• startup/runtime errors from the watcher about an invalid path.

Expected behavior

mcp-hmr <target>:<attr> should watch the server code directory by default so edits trigger reloads reliably.

Actual behavior

Hot reload does not reliably trigger on file changes unless users patch mcp_hmr.py locally (e.g., hardcode a watch directory).

Reproduction

1. Install mcp-hmr==0.0.3.2
2. Run:
   • mcp-hmr some.module:app (module target), or
   • mcp-hmr ./path/to/server.py:app (path target)
3. Edit a file inside the target server package/module (e.g., change a tool response)
4. Observe: no reload (or watcher error), requiring server restart.

Proposed fix

Derive a stable watch directory from the target:

• path:attr → watch the parent directory of the file
• module:attr → watch the directory containing the module/package on disk via find_spec()
• fallback → cwd

PR

I have a PR ready that implements the above watch-path derivation #58

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🔗 Similar Issues

Related Issues

• Run uvicorn on the main thread #29
• Django compatibility #48

🔗 Related PRs

#39 - mcp-hmr [merged]

👤 Suggested Assignees

• CNSeniorious000
• heisen273

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