Zero2Codex · OpenAI Codex CLI Starter

Master from Zero: OpenAI Codex CLI

5 progressive modules, 12 core concepts, 28 terminal hands-on tasks. From getting to know the tool to building a previewable expense tracker with Codex CLI, all in the browser.

View Learning Outline
5
Stages
12
Core Concepts
28
Hands-on Tasks
Created by Sager team, content credits to OpenAI Codex Official Docs, practice in browser terminal

After CompletingWhat You Can Do

🖥️

Proficiently Use Codex CLI for Daily Development

Master slash commands, AGENTS.md memory system, session management, and truly integrate AI coding assistant into your workflow.

⚙️

Build a Complete Project Configuration System

Learn Skills, Hooks, MCP—three extension mechanisms—to customize AI coding standards and automation for team projects.

🚀

Create a Web App from Scratch with Previewable Work

Apply all knowledge to build a pure-frontend personalized expense tracker in the browser terminal, and open the work preview to see the result.

Who Is ItFor

Frontend/Backend DevelopersWant to boost dev efficiency with Codex CLI but don't know where to start
Tech Team LeadsNeed to establish AI coding standards and configs for the team
Students / Career ChangersWant to quickly master AI coding tools and improve learning & project efficiency
Indie DevelopersWant to use AI tools to do the work of five people, from idea to launch

LearningOutline

How toLearn

Complete BeginnersFollow Stage 1 sequentially, every concept comes with hands-on practice, complete in 1-2 weeks
Used Codex CLI BeforeSkip Stage 1, dive into Stage 3 Skills/Hooks/MCP directly
Quick StartJump to Stage 5 project, learn earlier concepts as you go
Just Looking Things UpEach module has reference cards and command cheatsheets, look up as needed

PrerequisitesPrerequisites

Can use command-line terminal
Basic Git operations (clone, commit, push)
Understand basic syntax of at least one programming language
Have an OpenAI account (free to register)
Node.js project experience is a plus
Understand package.json and npm basics

✓ Required | △ Bonus, can learn without

LearningPrinciples

  1. Hands-on first, deep reading later — running one command beats reading all docs
  2. Every concept has hands-on tasks — not a forget-after-watching tutorial
  3. AGENTS.md is your project memory — build it as early as possible
  4. Start from copy, then customize — use existing configs first, adjust as needed
  5. Skills + MCP are efficiency multipliers — learn to create your own automation workflows
  6. Browser terminal with zero barriers — start practicing without installing anything