Comment by simonw

I posted some notes here that might be useful: https://simonwillison.net/2025/Sep/15/gpt-5-codex/

Even shorter version:

- New coding-specialist model called GPT-5-Codex, coming soon to the API but for now available in their Codex CLI, VS Code and Codex Cloud products

- New code review product (part of Codex Cloud) that can review PRs for you

- New model promises better code review, less pointless comments and can vary its reasoning effort for simple vs complex tasks