Today, we’re releasing GPT‑5‑Codex—a version of GPT‑5 further optimized for agentic coding in Codex. GPT‑5‑Codex was trained with a focus on real-world software engineering work; it’s equally proficient at quick, interactive sessions and at independently powering through long, complex tasks. Its code review capability can catch critical bugs before they ship. GPT‑5‑Codex is available everywhere you use Codex—it’s the default for cloud tasks and code review, and developers can choose to use it for local tasks via Codex CLI and the IDE extension.

Since we first launched Codex CLI⁠(opens in a new window) in April and Codex⁠ web in May, Codex has steadily evolved into a more effective coding collaborator. Two weeks ago, we unified Codex into a single product experience connected by your ChatGPT account, enabling you to move work seamlessly between your local environment and the cloud without losing context. Codex now works where you develop—in your terminal or IDE, on the web, in GitHub, and even in the ChatGPT iOS app. Codex is included with ChatGPT Plus, Pro, Business, Edu, and Enterprise plans.

With these updates, Codex moves closer to what we’ve been building toward all along—a teammate that understands your context, works alongside you, and reliably takes on work for your team.

GPT‑5‑Codex is a version of GPT‑5 further optimized for agentic software engineering in Codex. It’s trained on complex, real-world engineering tasks such as building full projects from scratch, adding features and tests, debugging, performing large-scale refactors, and conducting code reviews. It’s more steerable, adheres better to AGENTS.md⁠(opens in a new window) instructions, and produces higher-quality code—just tell it what you need without writing long instructions on style or code cleanliness.