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Codex - The Practical Guide
Bestseller
Highest Rated
Rating: 4.6 out of 5(1,242 ratings)
8,301 students

Codex - The Practical Guide

Boost your agentic engineering game by mastering OpenAI's Codex agent. From basics to advanced features
Bestseller
Highest Rated
Created byAcademind by Maximilian Schwarzmüller, Maximilian Schwarzmüller
Last updated 3/2026
English

What you'll learn

  • Use Codex efficiently to write code & build programs with AI
  • Build programs with AI efficiently by leveraging basic & advanced Codex features
  • Understand and use skills & context engineering
  • Plan and build projects with Codex & spec-driven development
  • Process tasks locally or in the cloud
  • Extend capabilities with MCPs
  • Fork sessions & leverage worktrees
  • Get better at agentic engineering using Codex

Course content

2 sections • 57 lectures • 2h 49m total length

  • Welcome To This Course!0:37

    Explore Codex through a hands-on demo project and master its basic and advanced features. Use the Codex CLI, IDE integration, and the native desktop app to maximize Codex.

  • An Introduction To Codex2:26

    Explore codex, the coding-optimized AI tool from OpenAI, including GPT-5.3 Codex Spark, and learn its CLI, IDE integration, desktop app, and web usage for secure, productive coding.

  • About This Course1:00
  • Codex Requirements & Usage1:44

    Codex requires a paid plan for full use, with a temporary free trial during the desktop release; access via ChatGPT subscriptions, other providers, or local models.

  • Controlling Data Privacy0:51

    Learn to manage data privacy by adjusting the data controls to prevent your data and code from being used to train future models in ChatGPT settings.

  • Getting Started: Codex CLI & IDE Integration2:27

    Install Codex via npm or Homebrew on any OS, then run the Codex CLI or VS Code extension to integrate Codex in projects, using prompts, models, and files.

  • CLI & IDE Integration - Basic Usage3:15

    Explore the terminal user interface for prompt engineering, learn to queue messages with tab and escape, and use CLI and IDE integration to generate an index HTML file with Codex.

  • Per-session Models & Other Configuration3:40
  • Codex 5.3 vs GPT 5.40:33
  • Getting Started: Codex Desktop App3:42

    Explore the Codex desktop app for macOS, learning to create and manage projects, configure models and reasoning, insert prompts, and open in VS Code, with a multi-session workflow.

  • Desktop App: UI Overview & Walkthrough2:57

    Explore the Codex desktop app to manage multiple projects, threads, and sessions with parallel agents, and customize settings, editors, git commits, and run actions; use the terminal and slash commands.

  • Tracking Your Codex Usage0:59

    Explore Codex usage, which depends on a paid subscription with two windows: five-hour and weekly. Check remaining usage via the native app, IDE drop-down, or CLI slash status.

  • Configuring Codex (Cross-Session)3:29

    Configure Codex across sessions by using global or local .codex/config.toml files to set model, reasoning, personality, and project-specific settings. Also explore desktop app options and AGENTS.md for cross-session behavior.

  • Understanding The Codex Security Model2:30

    Codex operates in a sandboxed environment with restricted file access, triggering permission popups for actions like git init and git add, while offering limited network and web search access.

  • Tweaking Codex Security Settings3:11

    Explore how to tweak Codex security settings, from dangerous config options like approval-policy to never and sandbox-mode full_access, to per-session permissions via the native app, the IDE extension, and the CLI.

  • Working with Profiles & One-off Configs1:06
  • Using Other Providers1:10
  • Managing & Resuming Sessions1:10

    Starting a new codex session creates an empty context, and you can resume older work using /resume in the CLI or from the IDE.

  • Version Control & Undoing Changes1:42

    Guard against unwanted edits by using version control to revert to commits when undo is unreliable. Commit changes with git add and git commit, and include config.toml for shared settings.

  • Advanced Ways Of Invoking The CLI1:35

    invoke the cli with an initial prompt to start an interactive session, or run codex exec non-interactively in a git-controlled project for automation via json output.

  • Codex CLI - Command & Options Cheat Sheet1:06
  • Context Window Management & Compaction2:47

    Manage a limited context window in Codex by monitoring size, applying automatic or manual compaction, and starting a new session to preserve critical context.

  • Course Resources & Community0:31

Requirements

  • Basic programming experience is required
  • You will need a Codex subscription to efficiently use it

Description

Codex is growing rapidly - and many developers consider it the best or amongst the best agentic engineering tools you can use these days! But unfortunately, many developers are also not using Codex very efficiently though.

If you’ve ever felt like you’re “using” Codex without really mastering it, this course is for you.

Codex – The Practical Guide is a hands-on, no-nonsense course designed to help you unlock Codex’ full potential. You’ll learn how to work with Codex efficiently, understand how it thinks, and confidently use the features that separate casual users from power users.

Yes, you can just start prompting - but to get the most out of it, you should probably go beyond basic, inefficient prompts and leverage the full suite of features Codex offers.

Starting from the fundamentals and quickly moving into advanced territory, you’ll explore essential concepts like context engineering and core commands before diving deep into powerful features such as different input modes, agent skills, MCPs, and more. Every feature is explained clearly - not just what it is, but why it matters and how to use it effectively in real projects.

You don’t need any special setup or prior experience beyond a Codex installation and subscription. By the end of the course, you’ll go from Codex novice to confident, advanced user - able to dramatically boost your productivity and build better software faster.

In this course, you’ll:

  • Learn the fundamentals of working with Codex the right way

  • Understand core commands and context engineering essentials

  • Master advanced, high-impact features like different input modes, agent skills, MCPs, and more

  • Make use of "Plan Mode" and manage configuration & permissions

  • Learn the WHAT, WHY, and HOW behind each concept - no black boxes

  • Use Codex in the CLI, IDE, native desktop app, and in the web (cloud)

  • Build a complete, real-world example project using Codex to see everything in action

If you want to stop guessing, stop underusing Codex, and start treating it like the powerful development tool it really is - this course will get you there.

Who this course is for:

  • Beginner and experienced developers who want to efficiently use Codex

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