GPT-5.2 Codex Blog - One API Access 500+ AI Models

Mar 19, 2026

How to Use GPT-5.2 Codex API

The landscape of automated software engineering has shifted dramatically with OpenAI’s official release of **GPT-5.2 Codex**. While its predecessor, GPT-5.1, introduced us to the concept of "reasoning models" in code, GPT-5.2 Codex represents the industry's first true "Agentic Engineer"—a model capable not just of writing code, but of maintaining long-horizon architectural context, navigating complex terminal environments, and autonomously refactoring massive legacy codebases.