OpenAI Blog
Feb 5
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-5.3-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.
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Building more with GPT-5.1-Codex-Max
Introducing GPT-5. 1-Codex-Max, a faster, more intelligent agentic coding model for Codex.
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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.
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Dec 18, 2025
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.
OpenAI Blog
Sep 15, 2025
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.
OpenAI Blog
Jun 9
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.
OpenAI Blog
Aug 7, 2025
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.
OpenAI Blog
May 16, 2025
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.
OpenAI Blog
Nov 13, 2025
Introducing GPT-5.1 for developers
GPT-5. 1 is now available in the API, bringing faster adaptive reasoning, extended prompt caching, improved coding performance, and new apply_patch and shell tools.
OpenAI Blog
May 20
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.
OpenAI Blog
May 29
How Braintrust turns customer requests into code with Codex
How Braintrust engineers use Codex with GPT-5. 5 to run experiments and code faster.
OpenAI Blog
Dec 11, 2025
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.