OpenAI Codex (AI agent)

Codex is an AI coding agent developed by OpenAI for software engineering tasks such as writing code and fixing bugs, released in April 2025 as Codex CLI. Codex is available through ChatGPT's web app, the Codex CLI, a desktop app for Windows and macOS, and several IDE integrations. In March 2026, OpenAI introduced Codex Security, an application-security agent designed to identify and fix software vulnerabilities.

By March 2026, Codex had grown to more than 2 million weekly active users, and OpenAI was positioning it as a broader enterprise agent platform that could eventually be used for tasks beyond software development.