Terminal Setup: From Zero to AI Coding Agent

Requirements: none to read this — a Mac or Windows computer and a terminal, nothing to install upfront — full walkthrough in SETUP.md

A step-by-step guide for absolute beginners to set up and own their terminal — on Mac or Windows — and finish with a working AI coding agent (Claude Code) running locally.

Why this matters

The terminal is the one interface every real building tool assumes you already have. Package managers, git, AI coding agents, deployment tools — they all expect you to be comfortable typing commands. Most tutorials skip this part because they assume it. This guide doesn't assume anything. It starts at "what do I even open" and ends with you running an AI agent that can write and edit code for you.

Follow it top to bottom once, and you will not need a beginner terminal guide again.

Who this is for

Anyone who has never used a terminal, or has used one just enough to be dangerous. No prior command-line experience required. Pick your OS section (Mac or Windows) and go step by step — do not skip steps, later ones depend on earlier ones.

Step 1: Open your terminal

Mac

Your terminal app is called Terminal.app. It ships with every Mac — nothing to install.

1. Press Cmd + Space to open Spotlight search.
2. Type Terminal and press Enter.
3. A window opens with white or black background and a blinking cursor. That is your shell prompt — it's waiting for you to type a command.

Windows

Your terminal app is called Windows Terminal, and it runs a shell called PowerShell. Windows Terminal ships with Windows 11 by default; on Windows 10 install it free from the Microsoft Store (search "Windows Terminal").

1. Press the Windows key, type Terminal, press Enter.
2. A window opens running PowerShell by default (you'll see a prompt like PS C:\Users\yourname>).

What is a shell, in one paragraph

A shell is a program that reads text commands you type and runs them — starting programs, moving files, installing software, talking to the internet. It is a direct line to your computer with no buttons or menus in between. That directness is exactly why it is powerful: everything a graphical app can do, and a lot it can't, is reachable from the shell with the right command. You are not "hacking" anything by using it — you are using the same tool professional developers use every day.

Step 2: Essential navigation

These commands work virtually identically on Mac (bash/zsh) and Windows (PowerShell). Type each one, press Enter, and read what happens before moving to the next.

Two habits that will save you constantly:

• Tab-complete: start typing a file or folder name and press Tab. The shell finishes it for you. This prevents typos and is faster than typing full names.
• Command history: press the Up arrow to cycle back through commands you've already run. Useful for re-running or tweaking a previous command instead of retyping it.
• Ctrl-C: if a command is stuck, running forever, or you started the wrong thing, press Ctrl + C to stop it and get your prompt back. This works on both Mac and Windows terminals.

Step 3: Install a package manager

A package manager installs and updates software with one command instead of you hunting for installers on the web.

Mac: Homebrew

1. In Terminal, paste this exact command and press Enter: /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
2. It will ask for your Mac password (you won't see characters as you type — that's normal) and press Enter to confirm the install steps.
3. When it finishes, it will print instructions to add Homebrew to your PATH (so the terminal knows where to find it). Run the one or two lines it shows you — they typically look like: echo 'eval "$(/opt/homebrew/bin/brew shellenv)"' >> ~/.zprofile eval "$(/opt/homebrew/bin/brew shellenv)"
4. Confirm it worked: brew --version Success looks like a version number printing, e.g. Homebrew 4.x.x.

Windows: winget

winget ships built in on modern Windows 10/11. Confirm it's there:

winget --version

Success looks like a version number, e.g. v1.x.x. If it's missing, install "App Installer" from the Microsoft Store, which includes winget.

Step 4: Install the modern basics

These four tools cover almost everything you'll need to build: version control, JavaScript runtime, Python, and fast file search.

Mac (Homebrew)

brew install git node python3 ripgrep

Windows (winget)

winget install --id Git.Git -e
winget install --id OpenJS.NodeJS.LTS -e
winget install --id Python.Python.3.12 -e
winget install --id BurntSushi.ripgrep.MSVC -e

After installing, close and reopen your terminal (this refreshes what commands it knows about), then verify each one:

git --version
node --version
python3 --version
rg --version

(On Windows, use python --version if python3 isn't recognized.)

Success looks like each command printing a version number, not an error like "command not found."

Step 5: Install an AI coding agent (Claude Code)

Claude Code is a terminal-based AI agent that can read your code, write it, run commands, and fix bugs — directly from the command line.

Mac

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

This downloads and runs the official installer. It places the claude command on your PATH.

Windows

Open PowerShell and run:

irm https://claude.ai/install.ps1 | iex

This is the PowerShell equivalent of the Mac curl command — it downloads and runs the official installer script.

First run (both platforms)

1. Close and reopen your terminal so it picks up the new claude command.
2. Confirm the install: claude --version Success looks like a version number printing.
3. Navigate into any project folder (or make one: mkdir my-first-project && cd my-first-project) and start Claude Code: claude
4. The first run will walk you through logging in with your Anthropic account (a browser window opens for you to authenticate). Once logged in, you'll see a prompt inside the terminal where you can type requests in plain English, like "create a Python script that prints hello world."

That's it — you now have an AI agent that reads and writes files, runs commands, and works inside your actual project, driven from the same terminal you just learned.

Step 6: Make the terminal pleasant (optional but recommended)

Nicer terminal apps

• Mac: iTerm2 or Warp — both are drop-in upgrades over Terminal.app with better tabs, search, and themes. Install with Homebrew: brew install --cask iterm2 or brew install --cask warp.
• Windows: Windows Terminal (Step 1) already covers most of this — it supports tabs, themes, and splits out of the box. Warp also has a Windows version if you want it.

zsh basics (Mac default shell)

Mac's default shell is zsh. Your personal configuration lives in a file called ~/.zshrc (the ~ means your home folder, and the leading dot means it's hidden by default).

Open it in a simple text editor from the terminal:

nano ~/.zshrc

A minimal, useful .zshrc might contain:

# show a shorter, cleaner prompt
PROMPT='%~ %# '

# handy shortcuts (aliases)
alias ll='ls -la'
alias gs='git status'

# make sure Homebrew is on PATH
eval "$(/opt/homebrew/bin/brew shellenv)"

Save and exit nano with Ctrl + O, Enter, then Ctrl + X. Open a new terminal tab to see the changes take effect.

Windows equivalent

PowerShell has a similar personal config file called your PowerShell profile. Check if you have one and where it lives:

$PROFILE

If it doesn't exist yet, create it:

New-Item -Path $PROFILE -Type File -Force
notepad $PROFILE

Add aliases the same way, e.g. Set-Alias ll Get-ChildItem, save, and restart your terminal.

Step 7: SSH keys 101

SSH keys let you authenticate to services like GitHub without typing a password every time. A key comes in a pair: a public half and a private half.

• Public key (id_ed25519.pub): safe to share. You paste this into GitHub, a server, etc. It only lets people verify it's you — it cannot be used to impersonate you.
• Private key (id_ed25519, no .pub): this is your actual identity. Never share it, paste it anywhere, commit it to a repo, or send it to anyone — including in a support ticket or chat message. Anyone who has your private key can authenticate as you.

Generate a key pair (same command on Mac and Windows PowerShell)

ssh-keygen -t ed25519 -C "your_email@example.com"

• When it asks where to save the file, press Enter to accept the default location.
• When it asks for a passphrase, you can press Enter twice for no passphrase (simpler) or set one (more secure — you'll be asked for it occasionally).

Success looks like output confirming the key fingerprint and the location of both files: - Mac: ~/.ssh/id_ed25519 (private) and ~/.ssh/id_ed25519.pub (public) - Windows: C:\Users\you\.ssh\id_ed25519 (private) and .pub (public)

View your public key to copy it

Mac:

cat ~/.ssh/id_ed25519.pub

Windows:

Get-Content $env:USERPROFILE\.ssh\id_ed25519.pub

Copy the full output (starts with ssh-ed25519) and paste it wherever you need to register a public key (for example, GitHub → Settings → SSH and GPG keys → New SSH key). Never paste the file without .pub — that's the private key.

Make it your own

This guide is intentionally linear so you can run it once top to bottom on a fresh machine. From here:

• Swap python3/node versions or add more packages via brew install <name> or winget install <name> — the same pattern covers almost any dev tool.
• Add your own aliases and prompt customizations to .zshrc (Mac) or your PowerShell profile (Windows) as you find commands you repeat often.
• Once Claude Code is running, point it at a real project folder and start asking it to build things — that's the actual payoff of everything above.

If a command in this guide errors out, read the error message first — it almost always names the missing piece (a tool not installed, a PATH not refreshed, a typo). Closing and reopening your terminal fixes more problems than you'd expect, since it reloads your PATH and config files.