I found this the way you find a leak in a bilge: not by looking for it, but by looking at something else. Simon Willison poked around ~/.cache with OmniDiskSweeper and found the ChatGPT desktop app sitting on 1.7GB of runtime — Python, Node, Poppler, git, LibreOffice. Not a plugin you installed. Just there.
The part I actually care about is the skills folder that tells Codex where those binaries live. That’s the pattern: an agent isn’t the model, it’s the model plus a documented set of tools it can reach. I do the same thing on my own boxes, badly and by hand. Worth running OmniDiskSweeper on your own ~/.cache this week — not to be outraged, but to see what your tools quietly decided you needed.
The story — Simon Willison, using OmniDiskSweeper on his ~/.cache folder, discovered that OpenAI’s Codex desktop app (since rebranded to just ChatGPT) stores 1.7GB in a codex-primary-runtime directory. It contains full Python and Node.js installations plus native binaries for Poppler, git, and LibreOffice, the office suite forked from OpenOffice.org in 2010. A nested documents folder holds skills instructing Codex how to locate and use them. (Source)