Building more with GPT-5.1-Codex-Max

Introducing GPT-5.3-Codex

GPT-5. 3-Codex is a Codex-native agent that pairs frontier coding performance with general reasoning to support long-horizon, real-world technical work.

GPT-5.3-Codex System Card

GPT‑5. 3-Codex is the most capable agentic coding model to date, combining the frontier coding performance of GPT‑5.

Introducing GPT-5.2-Codex

GPT-5. 2-Codex is OpenAI’s most advanced coding model, offering long-horizon reasoning, large-scale code transformations, and enhanced cybersecurity capabilities.

Addendum to GPT-5 system card: GPT-5-Codex

This addendum to the GPT-5 system card shares a new model: GPT-5-Codex, a version of GPT-5 further optimized for agentic coding in Codex. GPT-5-Codex adjusts its thinking effort more dynamically based on task complexity, responding quickly to simple conversational queries or small tasks, while independently working for longer on more complex tasks.

Addendum to o3 and o4-mini system card: Codex

Codex is a cloud-based coding agent. Codex is powered by codex-1, a version of OpenAI o3 optimized for software engineering.

How engineers at Nextdoor use Codex to build without limits

How engineers at Nextdoor use Codex with GPT-5. 5 to investigate hard-to-reproduce issues, build across platforms, and focus on product outcomes.

Introducing GPT-5 for developers

Introducing GPT-5 in our API platform—offering high reasoning performance, new controls for devs, and best-in-class results on real coding tasks.

How NVIDIA engineers and researchers build with Codex

Teams use Codex with GPT-5. 5 to ship production systems and turn research ideas into runnable experiments.

Introducing Codex

Codex for every role, tool, and workflow

Discover new Codex plugins, sites, and annotations that help analysts, marketers, designers, investors, and other teams get more done with AI.

Introducing GPT-5.2

GPT-5. 2 is our most advanced frontier model for everyday professional work, with state-of-the-art reasoning, long-context understanding, coding, and vision.

Introducing upgrades to Codex

Codex just got faster, more reliable, and better at real-time collaboration and tackling tasks independently anywhere you develop—whether via the terminal, IDE, web, or even your phone.