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← labtool2026-09-08

Claude Code, from zero

Nine chapters from install to ready, each with a do-it-now checklist you run on your own repo. CLAUDE.md, prompts, the workflow, models and effort, rules, skills, agents and hooks, with a prompt grader and a final readiness check.

Chapter 00 of 9

Install

Twenty minutes: install, sign in, pick a practice repo.

Twenty minutes, one terminal. By the end of this chapter Claude Code is installed, signed in, and sitting in a repo of yours waiting for instructions. Do the steps in order; the checklist at the bottom is yours to tick.

1. Install

terminal 
curl -fsSL https://claude.ai/install.sh | bash

The native installer keeps itself up to date. Homebrew (brew install --cask claude-code) and WinGet work too but do not auto-update. On Windows without WSL, install Git for Windows first so Claude has a Bash to run commands in.

2. Check it

terminal 
claude --version   # prints a version
claude doctor      # checks the install and your settings

If claude is not found, open a new terminal window first; the installer edits your shell profile and the old window has not read it.

3. Pick a practice repo

Not work. Not a fresh empty folder either. Something small of your own that already has tests and a git history, and that you would not mind breaking. A side project, an old exercise, a fork of a small library you know. You will use it for every chapter here.

No such repo? Clone one you understand and add two or three tests first. Ten minutes well spent: every technique below leans on having a test to run.

4. First start

terminal 
cd ~/code/my-small-project
claude
# Browser opens: sign in with your Claude account (Pro or Max include Claude Code).
# "Do you trust the files in this folder?"  y
# You are now at the > prompt. Type /help.

The trust prompt appears once per folder. It exists because a repo can carry instructions (CLAUDE.md, hooks) that Claude will follow; say yes to your own code, think twice about a stranger's. To leave: /exit, or Ctrl+D twice.

Signing in

A Claude Pro or Max subscription includes Claude Code. /login switches accounts, /status shows which one is active.

Updating

claude update when you want it now. The native installer does it on its own otherwise.

Editor

There is a VS Code extension and a JetBrains plugin. Learn the terminal first; the editor versions are the same thing with a diff viewer.

Do it now

0 of 5 done

In your own terminal, on your practice repo. Tick each one when you have seen the result. Ticks are saved in this browser only.

  1. You should see: claude --version prints a version number.

  2. You should see: The prompt says you are logged in and shows a > waiting for you.

  3. You should see: git status works there.

  4. You should see: You see the welcome box and the > prompt.

  5. You should see: You know at least three slash commands exist.