OpenAI Codex: The Complete Guide

OpenAI Codex: The Complete Guide is part of a book series called the Orange Book, walking a reader from installing OpenAI Codex to building and shipping products with it independently within a week. It covers Codex's five forms, the CLI, Desktop App, Cloud, IDE Extension and Chrome Extension, plus its mobile companion inside the ChatGPT app, and tracks changes across Codex releases such as the GPT-5.5 default model, an auto-review approval flow for low-risk actions, three Pro pricing tiers, and a persistent goal system that survives clearing or compacting a session.

It is distributed as downloadable PDF, EPUB and single-file HTML editions in both English and Chinese, with the English edition translated in native prose rather than literally, and each new version documented with a changelog covering what changed since the previous one.