With the popularity of AI coding tools rising among some software developers, their adoption has begun to touch every aspect of the process, including human developers using the tools to improve existing AI coding tools. We’re not talking about runaway self-improvement here; just people using tools to improve the tools themselves. In interviews with Ars Technica this week, OpenAI employees revealed the extent to which the company now relies on its own AI coding agent, Codex, to build and improve the development tool. “I think the vast majority of Codex is built by Codex, so it’s almost entirely just being used to improve itself,” said Alexander Embiricos, product lead for Codex at OpenAI, in a conversation on Tuesday. Codex now generates most of the code that OpenAI developers use to improve the tool itself. Codex, which OpenAI launched in its modern incarnation as a research preview in May 2025, operates as a cloud-based software engineering agent that can handle tasks like writing features, fixing bugs, and proposing pull requests. The tool runs in sandboxed environments linked to a user’s code repository and can execute multiple tasks in parallel. OpenAI offers Codex through ChatGPT’s web interface, a command-line interface (CLI), and IDE extensions for VS Code, Cursor, and Windsurf.Read full article Comments Read More