ChatGPT desktop app bundles LibreOffice and other tools in local runtime

While reviewing disk usage in his local cache directory, developer Simon Willison found a 1.7 GB folder named codex-primary-runtime associated with the ChatGPT desktop app. The folder contains a full Python installation, a full Node.js installation, and native binaries for Poppler, git, and the LibreOffice open-source office suite.

The LibreOffice binary included in the runtime is labeled libreoffice-headless, indicating it is configured for command-line or headless operation rather than a graphical interface. Additional components in the runtime include Poppler and git, suggesting the app bundles tools commonly used for document processing and version control.

A plugins directory within the runtime—specifically ~/.cache/codex-runtimes/codex-primary-runtime/plugins/openai-primary-runtime/plugins/documents—contains skills that instruct Codex how to locate and use these bundled binaries. This indicates the app is designed to leverage these tools for tasks such as document generation, editing, or conversion.

Willison notes that the ChatGPT desktop app was previously rebranded from OpenAI Codex, reflecting its evolution from a code-centric assistant to a broader AI assistant with local tool integration.