The ChatGPT/Codex app bundles a full copy of LibreOffice
Points and comments are a snapshot, not live.
OpenAI's ChatGPT desktop app bundles a full LibreOffice installation.
Simon Willison discovered that the OpenAI Codex desktop app (now rebranded to ChatGPT) stores 1.7GB in ~/.cache/codex-runtimes/codex-primary-runtime/. This includes full Python and Node.js installations, plus native binaries for Poppler, git, and LibreOffice (headless version at 429.7 MB). Skills in the plugins folder tell Codex how to find and use these binaries for document processing.
The discovery was made while using OmniDiskSweeper to examine cache folders. The LibreOffice bundle appears to be used for rendering and manipulating Microsoft Office documents.
What commenters are saying
Commenters broadly confirmed the finding: fresh installs of the ChatGPT desktop app on both macOS and Windows show the same LibreOffice headless binary present. Many defended the decision, arguing that LibreOffice is the only functional option for programmatic office document manipulation after trying Microsoft Office APIs, Google Docs DOM, and other alternatives. One commenter who spent two months on alternatives called the Office ecosystem "a cluster f." Others noted the attack surface concern of bundling such a large dependency, and some wished OpenAI would rewrite in Rust for smaller binaries.