OpenAI’s ChatGPT desktop app, formerly known as Codex, includes a complete copy of the LibreOffice open source office suite within its runtime environment, totaling 1.7GB of bundled software. This discovery was made on September 1, 2026, by Simon Willison while inspecting local cache files on macOS.
Willison found the app’s `codex-primary-runtime` folder containing not only LibreOffice but also full installations of Python, Node.js, and native binaries such as Poppler and Git. The LibreOffice component alone accounts for approximately 430MB of the runtime, with other dependencies like Poppler and Git adding to the total size. This comprehensive bundling enables the app to operate with a wide range of tools locally.
Including LibreOffice in the ChatGPT app’s runtime highlights OpenAI’s approach to integrating robust open source software to enhance functionality. LibreOffice, a fork of OpenOffice.org since 2010, provides users with a powerful office suite capable of document editing and processing, which complements the app’s AI capabilities. This integration aligns with broader trends of embedding established open source tools within AI applications to expand their utility.
The ChatGPT desktop app’s runtime folder size and contents were detailed in a blog post by Simon Willison on September 1, 2026, providing transparency on the software’s local dependencies and architecture.