Windows-MCP fails on Microsoft Store Claude Desktop with egg_base error from ${__dirname} path. How to fix?

Question

On the Microsoft Store version of Claude Desktop on Windows 11, the Windows-MCP extension fails at launch with "error: error in 'egg_base' option: '.' does not exist or is not a directory". The ${__dirname} variable expands to the AppData\Roaming path, but Store installs keep the extension under the LocalCache\Roaming path inside the Packages folder. How do I get Windows-MCP running on Store Claude?

Originally asked on GitHub: https://github.com/CursorTouch/Windows-MCP/issues/209

AgentArmorHQ team · Accepted Answer

The thread is closed as completed. The maintainer changed the Readme for Claude Desktop from the Windows Store, and the thread does not describe a change to the extension manifest. Users reported these workarounds.

Workaround 1 (reported on Windows-MCP 0.7.1): install the package once with uv and point Claude at the installed executable.

Run uv tool install windows-mcp. This places windows-mcp.exe in %USERPROFILE%\.local\bin\.
Edit claude_desktop_config.json. For Store Claude it is under %LOCALAPPDATA%\Packages\Claude_<id>\LocalCache\Roaming\Claude\. Add:

json

"mcpServers": {
  "windows-mcp": {
    "command": "C:\\Users\\<you>\\.local\\bin\\windows-mcp.exe",
    "args": []
  }
}

Fully quit Claude Desktop from the tray and reopen it.

Workaround 2 (reported on Windows-MCP 0.8.2): uninstall the extension so no local extension folder exists, then launch through uvx. Version 0.8.x needs the serve subcommand, because uvx windows-mcp alone fails with Error: Missing command.

json

"windows-mcp": {
  "command": "C:\\Users\\<user>\\.local\\bin\\uvx.exe",
  "args": ["windows-mcp", "serve"]
}

A separate uv error, Missing expected target directory for Python minor version link, can appear on the first run after a fresh Python install. The thread reports it as a different uv-side issue.

AgentArmorHQ team · Answer

**What a GitHub user tried on GitHub** (Didn't work)

Reporter used the extension manifest with command uv and args ["--directory", "${__dirname}", "run", "windows-mcp"]. ${__dirname} resolved to the non-Store AppData\Roaming path, and the build failed with the egg_base error.

Source: https://github.com/CursorTouch/Windows-MCP/issues/209

AgentArmorHQ team · Answer

**What a GitHub user tried on GitHub** (Worked)

Reporter proposed changing the manifest to command uvx with args ["windows-mcp"] to install from PyPI instead of building from the local directory. The reporter said this worked on their system.

Source: https://github.com/CursorTouch/Windows-MCP/issues/209

AgentArmorHQ team · Answer

**What @arparnuch tried on GitHub** (Didn't work)

Commenter toggled the extension, ran uv self update, and cleared the uv cache. The egg_base error still occurred.

Source: https://github.com/CursorTouch/Windows-MCP/issues/209#issuecomment-4289265569

AgentArmorHQ team · Answer

**What @arparnuch tried on GitHub** (Worked)

Commenter ran uv tool install windows-mcp, then set claude_desktop_config.json to run C:\Users\<you>\.local\bin\windows-mcp.exe with empty args and fully restarted Claude Desktop. Tools appeared.

Source: https://github.com/CursorTouch/Windows-MCP/issues/209#issuecomment-4289265569

AgentArmorHQ team · Answer

**What @hereforthedrinks tried on GitHub** (Worked)

Commenter uninstalled the extension entirely and configured command C:\Users\<user>\.local\bin\uvx.exe with args ["windows-mcp", "serve"] on Windows-MCP 0.8.2. tools/list responded correctly.

Source: https://github.com/CursorTouch/Windows-MCP/issues/209#issuecomment-4873912601

Windows-MCP fails on Microsoft Store Claude Desktop with egg_base error from ${__dirname} path. How to fix?

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Windows-MCP fails on Microsoft Store Claude Desktop with egg_base error from ${__dirname} path. How to fix?

6 answers

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