Hi Tom, Downgrading the PyPi package worked, thank you for that fix! GUI isn't necessary for my purposes, I'm basically just measuring the differences before and after mutations are made to a structure, using ChimeraX. From there I'm further processing the scraped data using python itself. There's only one method in my python code that deals with the ChimeraX stuff. I'm thinking that the PyPi module should be enough for my basic script, but I'm new to ChimeraX so please let me know if this makes sense to you as well. Right now I was doing "from chimerax.core.commands import run" and this seemed to import fine, though I apparently didn't declare the session parameter correctly. Do you know where I can find more documentation for the PyPi package? This link —(https://pypi.org/project/ChimeraX/) — just pointed me to the recipes that you wrote and I can't find any info on run() there. Thank you! Ishaan