Before any step in this book makes sense, you need two things: a place to write, and something to write with. You will not type code by hand, so that something is an AI agent. This chapter sets both up on the computer you already own, and leaves you a folder ready for the plan you write in the next part.
1.1.1Your own computer is enough
Your computer already runs Windows, macOS, or Linux. That is its operating system, the ground floor everything else installs onto, and any of the three builds everything in this book.
Any laptop from the last few years is enough: 8 GB of memory works, 16 GB is comfortable. Buy nothing and switch nothing, you start from what you have.
1.1.2The agent matters more than the editor
The one thing you cannot skip is an AI coding agent: the program that actually writes and changes your code. Since you never type code by hand, the agent is the engine this whole book runs on.
Two things decide how good it is: the agent itself, and the model powering it, the AI brain it thinks with. Keep an eye on both. A sharp agent on a weak model, or the reverse, will let you down.
1.1.3Install one agent and sign in
Where you and the agent work together is your choice, and it matters far less than the agent itself. Pick one of these two now:
- Want the simplest path? Install an agent-first tool like Claude Code, Codex, Cursor, or OpenCode, where the agent is the whole interface.
- More technical, or want full control? Install VS Code, a free editor from Microsoft, and run your agent inside it.
Installing is a download and a normal install, the same as any other app. Then two steps people are never warned about: you create an account, and you pay for a plan. You will run this agent constantly, so a plan that keeps up matters more than the exact tool you land on.
Hint: In 2026, Claude Code is the strongest agent for this, and it is the one this book uses. New options appear all the time, so ask your agent or search for the current best, then pick the one you feel comfortable in.
1.1.4Meet the terminal, where commands run
A command is one line of text that tells your computer to do something, and it goes in the terminal: a plain text panel where you type that line and your computer runs it. The terminal already ships with your operating system, and VS Code has one built in, so there is nothing to install.
You will barely use it by hand. Your agent runs commands there itself and shows you the output, usually asking permission first. That prompt is not a warning, it is the agent doing what it should: telling you before it touches your machine.
1.1.5Make a folder, and a home for your plan
Create one new folder on your computer for this project; it will hold everything you build. Inside it, add a folder named specs, the home for your spec, the written plan for what you are building. That is your whole workspace today.
The full project layout arrives later, when your agent scaffolds the real app. A specs folder is all you need for the planning that comes after this part.
1.1.6Have your agent finish the setup
Every chapter from here ends with a prompt: a block of text you copy and paste to your agent as its instructions. This is your first one. With the agent installed, open it and paste this. It checks your machine, builds your folders, and confirms everything works before you go further:
Do this now: install your agent, sign in, pay for a plan, then paste the prompt and let it create your project folder with a specs folder inside.
