OpenAI releases GPT-5-Codex, a new model built specifically for programming

OpenAI has released GPT-5-Codex, a brand-new model optimized specifically for programming, with broad applications across Codex CLI, IDE extensions, web, mobile, and GitHub code review. The model inherits GPT-5’s dynamic reasoning time feature, automatically allocating computational resources based on task complexity—providing instant responses for simple tasks and deeper reasoning for more complex ones.