Get the Claude desktop app installed, open the Code tab, and create your first project folder — the foundation for everything you'll build.
This course — like every course in The Build — is a guided walkthrough of Claude Code. Each module gives you prompts to paste, small decisions to make, and steps to follow. By the end, you'll have a working tool or system running on your computer, built entirely by you (with Claude Code doing the typing). You don't need to know how to code. You just need to follow along and read what comes back.
Claude Code is the version of Claude that can write files, run commands, and build things. Instead of just answering your questions, it takes actions on your computer. You type an instruction in plain English — "create a folder called comms-gut-check" — and Claude Code does it. It lives inside the Claude desktop app as a dedicated tab. No command line required. By the end of this course, you'll have used that same pattern to build a complete web application.
</> icon in the upper-left of the desktop appDon't worry if "Git" is unfamiliar — it's just a tool Claude Code uses behind the scenes. The setup guide walks you through it.
Copy the prompt below, paste it into the Claude Code chat, and press Enter.
Create a new project folder called comms-gut-check. Inside that folder, create a file called CLAUDE.md and use it as the project description for what we're building: a web app called The Comms Gut Check, where someone pastes any communication they've written and gets honest, structured feedback — covering whether it's clear, whether it has jargon, who might push back and why, whether the tone is right, and a suggested rewrite. Note that setup is complete but no app pages have been built yet. In the same CLAUDE.md file, add standing instructions for this project: only build or create things when I explicitly ask you to. If I ask to pick up where we left off or continue, read this file, tell me the current status, and then wait for my next instruction before doing anything.
Claude Code will ask permission before it touches anything on your computer. You'll see a dialog or an in-chat prompt — something like "Allow Claude to create files?" or a button labelled Allow Once. Click it. This is expected and normal. Claude Code will keep asking each time it does something new, and you can click Allow Once every time. You're in control throughout — Claude can't do anything on your computer without your explicit approval first.
Claude Code will then create the comms-gut-check folder inside the folder you selected when you opened Claude Code, and add a file called CLAUDE.md inside it with the project description. You'll see it confirm this in the chat when it's done.
To verify it worked: open Finder (Mac) or File Explorer (Windows) and look for the comms-gut-check folder. Inside, you should see a file called CLAUDE.md.
The project description you just created acts as Claude Code's standing briefing document. It lives in a file called CLAUDE.md — a plain text file that uses simple symbols (like # for headings and **bold** for bold) to add light formatting. That format is called "markdown" — you may come across it in other tools as you build, and now you'll recognize it. Every time you open a new Code session, Claude reads this file to understand what you're building, what decisions have already been made, and what the rules are. Without it, Claude starts fresh every session with no memory of your project. With it, you can pick up exactly where you left off.
As you build more complex tools across this track, your project description will grow into a living spec — capturing your design choices, how the tool connects to Claude, your folder structure, and anything else Claude needs to know. The best part: you never have to edit it directly. Just tell Claude Code what's changed — "update the project description to note that we changed how the connection to Claude works" — and it rewrites its own instructions.
Most likely cause: Claude Code doesn't have a folder selected. Close the app, reopen it, click the </> icon, and pick your home folder or Documents folder when it asks.
Git Bash wasn't found (Windows only). Uninstall Git, then reinstall it accepting all defaults this time. See the setup guide for the full Git walk-through.
Just ask Claude Code in the chat: "Where did you create the comms-gut-check folder?" It will tell you the exact location.
Take a screenshot of whatever you're seeing and paste it into Claude Chat (the regular chat product — not Claude Code). Claude can read screenshots and walk you through almost anything you're stuck on.