Simon Willison · 2026-09-01 · notable
Simon Willison — the ChatGPT desktop app ships a full copy of LibreOffice
Simon Willison found 1.7GB of bundled software in the ChatGPT desktop app's cache: full Python and Node.js installs plus native binaries for LibreOffice, Poppler, and git. Skills files tell the agent where to find them.
The ChatGPT desktop app keeps a 1.7GB private toolbox so its agent can open PDFs and office documents on your machine.
Key specs
| Bundled cache | 1.7 GB |
|---|
What is it?
Simon Willison went looking for disk space with OmniDiskSweeper and found ~/.cache/codex-runtimes/codex-primary-runtime holding 1.7GB of software shipped with OpenAI's desktop app, which used to be called Codex. Inside are a full Python installation, a full Node.js installation, and a set of native binaries.
How does it work?
The 771.0 MB of native binaries in the app break down as LibreOffice at 429.7 MB, Poppler at 187.9 MB, and git at 148.1 MB, sitting next to Node.js at 446.4 MB and Python at 440.6 MB. Skills stored in the documents folder tell the app where these binaries live and how to call them, so document conversion happens locally.
Why does it matter?
Willison's find shows how a desktop coding agent gets its hands. Rather than asking a model to parse a PDF or a spreadsheet, the ChatGPT app shells out to real, well-tested tools it already carries. It also accounts for a large chunk of local disk use that only turned up with a disk-usage scanner.
Who is it for?
desktop AI users and agent builders