Placeholder Academy

A course you run in your own terminal

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 · one-time Premium upgrade

Three frontier CLIs, taught side by side

Agentic coding tools read your files, run commands, edit code, and carry out multi-step tasks — asking permission at the points that matter. Learn the concepts once, and the commands for each.

Claude Code

Fundamentals through mastery: installation, slash commands and skills, agentic workflows, plus the Advanced Track and a searchable cheatsheet.

OpenAI Codex CLI

From a free overview 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.

Public

Open to everyone

Core Concepts and Getting Started are fully public — no account, no sign-up. Read them right now.

Start with Core Concepts

Premium

Everything, forever

One purchase unlocks the searchable Cheatsheet, the Advanced Track, and every provider deep-dive — and your progress follows your login here too.

See what's included

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.