Claude Fails to attach to MCP because "ModuleNotFoundError: No module named 'httpx'

[danieljeannetot]

Hi,

First thanks for developping this addon. It looks great, at least on paper.

I have been trying to run it for a few hours now, no success.

What was initially a Claude Desktop client error (MCP fails to execute, known issue of the current 1.01.774 Desktop build) was supposedly solved by downgrading to 1.0.332

I have been trying now on Desktop Claude 1.0.332, alas no success either.
I checked the logs produces by Claude: below seems to be the error.

ModuleNotFoundError: No module named 'httpx'

Anyidea how to fix this?

[IMNMV]

Thanks for trying the package :)

That error means the Python environment Claude Desktop is pointing to doesn't have the required dependencies installed. The easiest fix is to switch to uvx, which handles all Python dependencies automatically.

You'd first install uv, and if you don't have it:

curl -LsSf https://astral.sh/uv/install.sh | sh

Then in RStudio:

library(ClaudeR)
install_clauder()

This will make a config that uses uvx clauder-mcp instead of pointing to a local Python path.
Restart Claude Desktop after updating the config.

If you can't use uvx, you can fix it manually by installing the dependencies in the same Python environment that Claude Desktop is using:

/path/to/your/python -m pip install httpx mcp

Replace /path/to/your/python with whatever Python path is in your Claude Desktop MCP config file.

Let me know if that resolves it!