Codex Orange Book: A Comprehensive Guide to OpenAI's Codex

This repository provides an unofficial, continuously updated guide to OpenAI's Codex, aimed at developers, independent developers, and heavy AI tool users. It offers a full-lifecycle walkthrough from installation to practical application, positioning Codex as an advanced engineering agent capable of executing complex software development tasks, rather than just a code generation tool. The guide's primary benefit is enabling users to leverage Codex effectively for project execution and workflow automation.

How It Works

The guide details Codex's evolution from earlier AI coding tools (Copilot for completion, ChatGPT for dialogue, Cursor for project collaboration) to its current role as an "engineering agent." This agentic capability allows Codex to understand project context, read files, plan tasks, modify code, run commands, and manage results, effectively acting as an AI programming assistant that can execute defined engineering tasks. It emphasizes Codex's ability to integrate into various workflows through multiple interfaces: a desktop App, a Command Line Interface (CLI), an IDE Extension, and a Web interface for cloud-based GitHub project management.

Quick Start & Requirements

The guide offers multiple installation and usage paths:

• Codex App: Recommended for beginners, available for Windows and macOS.
• Codex CLI: For terminal users, available for macOS, Windows, and Linux.
• Codex IDE Extension: Integrates directly into VS Code, Cursor, and Windsurf.
• Codex Web/Cloud: For remote GitHub project management.

Prerequisites include Git, a code editor (VS Code/Cursor), Node.js (for CLI), Python, a GitHub account, and a ChatGPT account with access to Codex-enabled plans. Setup involves installing the chosen interface and configuring access, with a strong recommendation to start with a test project directory.

Highlighted Details

• Multi-Modal Access: Supports desktop app, CLI, IDE extensions, and web interfaces for flexible integration into diverse development environments.
• Agentic Workflow: Positions Codex as an engineering agent capable of understanding context, planning, executing, and verifying tasks within a project lifecycle.
• Structured Workflow: Promotes a six-step process: requirement decomposition, plan formulation, iterative implementation, testing, code review, and commit/documentation.
• Extensibility: Covers concepts like Skills (predefined workflows) and MCP (connecting external tools/data), along with third-party model integration via tools like CC Switch.

Maintenance & Community

The guide is presented as a "continuously updated version" with a last verified date of 2026-06-22. It provides links for online reading and PDF download, but does not specify community channels like Discord or Slack.

Licensing & Compatibility

The guide is described as an "unofficial open-source guide" ("非官方开源指南"). However, the README does not specify a particular open-source license for the guide itself. It explicitly states it is not official OpenAI documentation and that users should refer to official OpenAI resources for product details and pricing.

Limitations & Caveats

This guide is unofficial and does not represent OpenAI. Codex is rapidly evolving, so installation methods, model names, and features may change; users must consult official OpenAI documentation for current information. The guide focuses on Codex's capabilities and usage, not on official OpenAI product guarantees. Third-party tool integrations (like CC Switch, DeepSeek) are noted as unofficial and subject to their respective providers' terms.