OpenAI has enhanced its Codex AI coding agent by integrating a customised version of GPT-5. This upgrade allows Codex to dedicate processing time, ranging from seconds to hours, to individual tasks. GPT-5's advanced reasoning capabilities facilitate multi-step reasoning, planning, and iterative processes, enabling Codex to function more autonomously.
GPT-5-Codex is designed for real-world software engineering, excelling in both quick, interactive sessions and long, complex tasks. It can catch critical bugs before they ship. The upgrade includes a rebuilt Codex CLI centred around agentic workflows, a new IDE extension, GitHub integration for code reviews, and workflow updates to Codex web. Codex is available with ChatGPT Plus, Pro, Business, Edu, and Enterprise plans.
