# OpenAI — Addendum to o3 and o4-mini system card: Codex

- Company: OpenAI (openai.com)
- Announced: 2025-05-16T08:00:00+00:00
- Category: model-update
- Subject: GPT / ChatGPT / API
- Models affected: codex-1, o3
- Source: https://openai.com/index/o3-o4-mini-codex-system-card-addendum
- Record: https://forck.live/items/560-addendum-to-o3-and-o4-mini-system-card-codex

OpenAI describes Codex, a cloud-based coding agent powered by codex-1, a version of o3 optimized for software engineering through reinforcement learning on real-world coding tasks.

## Evidence

Verbatim from https://openai.com/index/o3-o4-mini-codex-system-card-addendum:

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

---

Record: https://forck.live/items/560-addendum-to-o3-and-o4-mini-system-card-codex
Catalogue: https://forck.live/llms.txt
Feed: https://forck.live/feed.md