What is Codex?
Codex is OpenAI's coding agent for software development tasks. It runs in the ChatGPT desktop app, as a command line tool, in code editor extensions, on the web, in cloud environments and through an SDK.
OpenAI's glossary describes the Codex CLI as a terminal client for running Codex interactively or in scripts. A Codex cloud chat is one that runs remotely in a cloud environment. OpenAI's documentation also lists a code editor extension and remote access, and says the ChatGPT desktop app includes Codex.
Background from ai notis, not part of the news. Checked against its sources on 4 Oct 2026.
Our sources
- ChatGPT and Codex overview · OpenAI
- ChatGPT and Codex glossary · OpenAI