Placeholder Academy
Master the AI coding CLIs developers actually use
A hands-on course that gets you fluent in the three frontier-model coding tools — Claude Code (Anthropic), OpenAI Codex, and the Google Gemini CLI — plus how to choose between them and prompt each one well.
19 modules · knowledge checks, XP & badges · one-time Premium upgrade
Three frontier CLIs, taught side by side
Agentic coding tools run a frontier model directly in your terminal: they read your files, run commands, edit code, and carry out multi-step tasks — asking permission at the points that matter. This course teaches the three leading tools together, so you learn the concepts once and the commands for each.
Claude Code
Fundamentals through mastery: installation, slash commands and skills, agentic workflows and subagents, plus a five-module Advanced Track and a searchable command cheatsheet.
OpenAI Codex CLI
From a free overview of the OpenAI coding surfaces to a full
deep-dive: codex exec, approval and sandbox modes,
AGENTS.md, MCP, and Codex cloud.
Google Gemini CLI
The Gemini CLI, API, and AI Studio — auth options, flags, slash
commands, GEMINI.md, and model selection — starting
free and going deep in the premium module.
Provider-neutral throughout: a dedicated module helps you choose among Claude, OpenAI/GPT, and Gemini on reasoning, speed, cost, context, and agent ecosystem — and another teaches prompt patterns that port across all three.
Start instantly. Go as deep as you want.
The course is organized in three tiers, so you can try it before you share so much as an email address.
Public
Open to everyone
Core Concepts and Getting Started are fully public — no account, no sign-up, nothing to install. Read them right now.
Start with Core ConceptsFree account
The full free track
A free account unlocks the rest of the free modules — prompts, agentic workflows, the OpenAI and Gemini overviews, the model-chooser guide, and the interactive playground — and lets your progress, XP, and badges follow your login.
Create a free accountPremium
Everything, forever
One purchase unlocks the searchable Cheatsheet, the five-module Advanced Track, and the OpenAI Codex, Gemini CLI, and cross-model prompting deep-dives — plus every future premium module.
See what's includedBuilt for doing, not just reading
Hands-on drills
Every module ends with exercises you run in your own terminal and a knowledge check that tracks your completion.
Progress, XP & badges
Work through the modules to level up and collect badges — a running scoreboard of what you've actually covered.
Fast and lightweight
Static pages, no heavyweight app to load. Lessons open instantly and read well on a phone, a laptop, or a second monitor next to your terminal.
Simple pricing
The fundamentals are free forever. Premium is $49 one-time — no subscription. Already bought it? Redeem your license key on the pricing page.