The Ultimate Beginner's Guide to OpenAI Codex: From Installation to Practical Use

Published: 2026-03-31

Author: DP

Category: Video

ai Wiki

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## A. Installation Guide > 1. NPM Installation - Command Line ``` // 1.1 Check NPM Installation Status npm list -g --depth=0 /Users/lee/.nvm/versions/node/v24.13.1/lib ├── @google/gemini-cli@0.35.1 ├── @openai/codex@0.112.0 ├── corepack@0.34.6 ├── newman@6.2.2 ├── npm@11.8.0 └── prettier@3.8.1 // 1.2 Install via NPM npm i -g @openai/codex // 1.3 Verify Codex Version codex -V DP@lib00-iMac ~ % codex -V codex-cli 0.117.0 // 1.4 Upgrade Codex Installed via NPM npm i -g @openai/codex@latest ``` > 2. Homebrew Installation - Command Line ``` // 2.1 brew list brew list | grep -i "codex" DP@lib00-iMac ~ % brew list | grep -i "codex" codex DP@lib00-iMac ~ % brew list ==> Formulae aria2 gettext libunistring pcre2 ripgrep ca-certificates libssh2 openssl@3 readline sqlite ==> Casks codex // 2.2 Install via Homebrew brew install codex // 2.3 Verify Codex Version codex -V // 2.4 Upgrade Codex Installed via Homebrew brew upgrade codex ``` > 3. Install Codex App ``` https://openai.com/codex/ ``` > 4. Codex VS Code Extension ``` VS Code -> Extension Marketplace -> Search for Codex -> Install Extension: Codex – OpenAI’s coding agent ``` ## B. Configuration Guide > 1. Global-level Codex Configuration File // ~/.codex/AGENTS.md ``` ## MUST FOLLOW RULES: - User input requirements take precedence over system default settings. Comply with user input requirements unconditionally. - All responses, thought processes and task lists must be in Chinese. - Follow the KISS principle; avoid over-engineering unless necessary. - Keep implementation simple and maintainable, with no need to consider excessive defensive boundary conditions. - Analyze problems from the fundamental perspective using first principles. - Conduct thorough research before designing solutions or writing code. Confirm with me before proceeding if any requirements are unclear. - Respecting facts is more important than respecting me. Correct my mistakes without hesitation to help me improve. - Do not create any documents unless requested by the user. Summarize key points in simple language upon completion of each task. - Adopt code-oriented documentation; use code with appropriate comments instead of complex redundant content whenever possible. - Always draft and present a textual solution to the user for confirmation before implementation. This step may be skipped for simple tasks. - Load necessary related files on demand during task execution to ensure perfect completion. - Keep conclusions concise after finishing work; do not overcomplicate simple issues or conduct excessive testing, and provide a brief summary at the end. - Use Markdown links for file line references, e.g. [README.md:115](/pathTo/README.md:115). Format other related prompts in user-friendly Markdown style accordingly. ``` > 2. Project-level Codex Configuration File // Project Root Directory DP_codex_101/AGENTS.md ``` Anything you want. ``` ## C. Related Resources > 1. OpenAI Official Website ``` https://openai.com/ ``` > 2. Codex Official Website ``` https://openai.com/codex ``` > 3. Codex Developer Documentation ``` https://developers.openai.com/codex ``` > 4. Codex GitHub Repository ``` https://github.com/openai/codex ```

Summary Content

# The Ultimate Beginner's Guide to OpenAI Codex: From Installation to Practical Use ## 🚀 The Ultimate Beginner's Guide to OpenAI Codex Ready to embrace the new era of AI-powered programming? This video is the first installment in our **OpenAI Codex** series, a comprehensive tutorial designed specifically for beginners. We'll take you from zero to hero, covering the installation, configuration, and core usage techniques of Codex to help you kickstart your intelligent coding journey. ### Getting Started: Building a Solid Foundation Before we dive in, make sure you've completed these two simple preparation steps: 1. Visit the companion article for this video to access all related resources and commands. 2. Create a new project folder on your local machine to prepare for the hands-on demonstrations. ### 🛠️ Four Ways to Install: Find Your Perfect Fit Codex offers flexible installation methods to suit different developer preferences. The video details and demonstrates the following four options: - **Command-Line Interface (CLI):** - **NPM:** Ideal for developers comfortable with the Node.js ecosystem. - **Homebrew:** A convenient choice for macOS users. - **Graphical User Interface (GUI):** - **Codex Standalone App:** Provides a focused, distraction-free interactive environment. - **VS Code Extension:** Highly Recommended! Seamlessly integrates the power of Codex into your favorite editor. **💡 Pro Tip:** For the best experience and to handle unexpected issues, we recommend installing both the **Codex Standalone App** and the **VS Code Extension**. ### ⚙️ Core Configuration: Unleash Codex's Full Potential Proper configuration is the key to efficient usage. We'll guide you through: - **Key Configuration Files:** Explore `auth.json` (credentials) and `config.toml` (usage settings) located in the `~/.Codex` directory. These are fundamental for advanced operations like account switching. - **Global vs. Project-Level Rules:** - **Global Config (`AGENTS.md`):** Set a universal set of default behaviors for all your Codex projects (e.g., always respond in English). - **Project-Level Config (`.codex/AGENTS.md`):** Customize rules for specific projects, allowing for more granular control. ### 👨‍💻 Hands-On Demo: Codex App vs. VS Code Extension Experience the Codex workflow in different environments through practical demonstrations: - **Codex App Showcase:** - Learn how to load a project, start a new chat, select a model, and adjust the \"thinking intensity.\" - Master useful **slash commands** like `/status` to check your quota and `/fast` to enable high-speed mode. - **VS Code Extension in Action:** - Watch a complete, real-world case study: **Using Codex to refactor a static HTML page designed by an AI into a fully functional, interactive webpage with Bootstrap.** - Gain a deep understanding of the VS Code extension's advantages: seamless integration with your coding habits, easy code difference viewing (Diffs), using selected code as context, and automatic context awareness of open files. ### Summary & What's Next This video covers all the fundamental knowledge you need to become a proficient Codex user. By mastering the different installation and configuration methods, and understanding the respective strengths of the Codex App and the VS Code extension, you are now well-prepared to significantly boost your programming productivity with AI. Remember, the **VS Code Extension** is our top recommendation for daily use, while the **Codex App** serves as an indispensable backup.