bozhoudev/codex-orange-book

The Codex Orange Book is a free, community-written guide that teaches you how to use OpenAI's Codex from scratch. Instead of just explaining what buttons to click, it walks you through the entire journey: installing the tool, understanding its interface, and using it to complete real software engineering tasks. You can read it online or download it as a PDF. At a high level, the guide explains that Codex is not just another chatbot that writes code for you. It is an AI agent that can enter a real project, read files, understand the context, make a plan, modify code, run tests, and hand you a finished result to review. The guide breaks down how to use Codex across its four main entry points: a desktop app (recommended for beginners), a terminal command line, an IDE extension for editors like VS Code, and a web interface for cloud-based projects. It also covers core features like automation, memory, and Git workflows. This guide is written for a few specific types of people. If you have never used Codex but want to learn it systematically, this is for you. It is also useful if you already know how to code but are not sure how to integrate an AI agent into a real project. The guide is especially helpful for independent developers, product managers, or technical team leads who want to build a standard workflow around AI. It even includes practical examples, like building a pet snack website, creating an admin dashboard, and making a promotional video. One of the most notable things about the guide is how it frames the evolution of AI coding tools. It puts today's tools into perspective: Copilot helped you finish lines of code, ChatGPT helped you think through problems, Cursor let you edit files alongside AI, and Codex acts as an executor that drives a task from start to finish. The guide emphasizes using these tools together rather than treating them as replacements. It also stresses safety, repeatedly reminding you to use practice projects first, commit your code to Git before making changes, and always review what the AI modified before accepting it.