How NVIDIA engineers and researchers build with Codex

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-5.3-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.

Building more with GPT-5.1-Codex-Max

Introducing GPT-5. 1-Codex-Max, a faster, more intelligent agentic coding model for Codex.

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.

How Braintrust turns customer requests into code with Codex

How Braintrust engineers use Codex with GPT-5. 5 to run experiments and code faster.

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.

How Ramp engineers accelerate code review with Codex

How Ramp engineers use Codex with GPT-5. 5 to review code and ship improvements, allowing them to get substantive feedback in minutes instead of hours.

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.

Introducing Codex

First look at GPT-5

See how a group of leading developers use GPT-5 for the first time.

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.