Module 3, Lesson 3: Installing Claude Code

At this point you should have your specs out and saved in your project via WebStorm. If you followed along in the previous lesson, you've got a /specs folder with feature requirements sitting in your codebase. Now we're about to add the most powerful tool in this whole course.

In this lesson, we're installing Claude Code — and this is the point where things get genuinely exciting.

Before We Start

Here's what I'd expect you to have in place before this lesson:

From previous lessons:

• WebStorm installed, project created, and MCP connected to Claude Desktop — from Module 3, Lesson 1
• Your /specs folder exists in the project — from Module 3, Lesson 2
• You're comfortable opening the terminal inside WebStorm (we'll use it here)

Tools / setup you'll need:

• WebStorm open with your project loaded
• A working internet connection
• On Windows: Windows 10 or 11 (WSL is required — covered below)

By the end of this lesson, you'll:

• Have Claude Code installed and ready to run from the WebStorm terminal
• Be logged in and authenticated with your Claude Pro account
• Know that it's working and be set up for everything that follows in Module 3 and 4

About This Lesson

Duration: ~9 minutes video + ~15 minutes setup
Skill Level: Intermediate
What You'll Build: A working Claude Code installation inside your WebStorm terminal — your agentic coding environment, ready to go.

This is a short setup lesson, but it's a big transition. Everything we've done so far — the research, the docs, the specs — has been building toward this moment. Claude Code is the tool that's going to take all that planning and actually turn it into a working product. Take your time with the setup here. Five minutes of patience now saves hours of friction later.

Watch the Lesson

What We're Covering

Here's what I'm walking you through in this lesson:

• What Claude Code actually is — "agentic coding tool" is the technical label, but I'll tell you what it actually means for how we work
• Installing on Mac — the one-command install and how to verify it's working
• Installing on Windows — why WSL is the right path and what that setup looks like
• Authenticating with your Claude account — the one-time login flow that ties Claude Code to your Pro subscription
• Verifying it's all working — what a successful install looks like before we move on

1. Let's Set the Scene (~0:00)

At this point, we've got our specs out and saved in the project via WebStorm. In the previous lesson, we got a few of them done together. I hope you're excited, because we are about to talk about something even more exciting.

Up until now, we've been using Claude Desktop to control JetBrains via MCP. From this lesson forward, we're going to move slowly but completely into working from inside JetBrains itself — that's going to be our main sandbox. And the tool that makes that possible is Claude Code.

Claude Code is what's called an agentic coding tool. That's a lot of lingo for something that, at its core, just means: a tool that assists you in writing a lot of code — and does it autonomously, inside your actual project. Unlike Claude Desktop (which lives in its own window and reaches into your editor via MCP), Claude Code runs directly in the terminal inside your project folder. It knows your codebase, it can read your files, and it can write and edit code without you having to copy and paste anything.

There's also a lot more you can do with Claude Code beyond just writing code. We'll see that over the next few lessons.

For now, all we need to do in this lesson is get it installed.

2. The Core Idea

2.1 What Makes Claude Code Different from Claude Desktop

We've been using Claude Desktop since Module 1. It's great — and we'll still use it for certain things. But there's a key difference when it comes to building.

Claude Desktop is like having a very capable assistant sitting next to you. You talk to it, it gives you things back, and you bring those things into your project manually (or via MCP). That works well for research, documentation, and planning.

Claude Code is different. It runs inside your terminal, inside your project. When you give it a task, it can read your files directly, understand the context of your whole codebase, write new code, edit existing code, and run commands — all without you acting as the middleman. It's not a chatbot you consult. It's more like a junior developer who already has access to your repo and is sitting at the keyboard.

That's what "agentic" means in practice: it takes action, not just advice.

2.2 What You Need Before You Can Install

One important thing: Claude Code requires a paid Claude account to authenticate. Your Claude Pro subscription covers this — you don't need a separate API key. We'll walk through the login step after installation.

3. Let Me Show You How It Works

3.1 Opening the Terminal in WebStorm

Everything we're about to do happens in the terminal inside WebStorm. If you haven't used it before, here's how to open it:

• Mac: Press Cmd + E, then click Terminal
• Windows: Press Alt + E, then click Terminal

It opens a panel at the bottom of WebStorm. It might look a bit different from mine depending on your setup — that's fine. This is where we type commands that interact with your system directly.

3.2 Installing on Mac (Recommended Method)

Head to claude.ai/download or search for "Claude Code" — you'll find the install page. The page will detect your operating system and show you the relevant command.

The current recommended install command for Mac (and Linux) is:

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

Copy that command, paste it into your WebStorm terminal, and hit enter. It'll run, install Claude Code, and tell you when it's done. You're looking for an "Installation complete" message (or similar). If you see that, you're good.

Once it's installed, verify it worked by running:

claude --help

If you see a list of available commands and options come back, you're installed and ready.

To clear the terminal screen after that, run:

clear

(Or on Mac: Ctrl + L)

3.3 Installing on Windows

If you're on Windows, there are two solid options:

Option A — Native Windows Installer (simplest)

Open PowerShell and run:

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

This is the native Windows installer. It doesn't require WSL or Node.js — it installs a standalone binary directly. This is the simplest path if you're on Windows 10 or 11.

Option B — WSL (Windows Subsystem for Linux)

This is the path I walk through in the video, and it's still a solid option — especially if you plan to do more development work. WSL gives you a Linux environment running inside Windows, which means you get a Mac-like development experience on your Windows machine.

To install WSL, open PowerShell as an administrator and run:

wsl --install

This installs WSL along with an Ubuntu distribution. After that, you'll install Claude Code from inside your WSL terminal using the same curl command as Mac:

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

I've linked a comprehensive WSL setup guide in the Resources section below if you need help with this step. It walks you through everything, including Git setup.

Once you're set up on either path, verify the install the same way:

claude --help

4. Logging In and Authenticating (~6:20)

Once Claude Code is installed, the first time you run it, it needs to connect to your Claude account. Here's how to do that.

In the terminal, run:

claude auth login

This will open your browser. Make sure you're already logged into Claude in that browser before you run this. It'll prompt you to authorise Claude Code — say yes, authorise it, and then you'll see a "Let's build something great" message in the browser. Close that and go back to your terminal.

In the terminal, you should see: Login successful.

Now type:

claude

It'll ask whether you trust the current folder (it's about to be able to make changes to it). Say yes.

If everything's wired up correctly, you'll see a welcome screen that tells you:

• You're logged in as Claude Pro
• Your name
• The name of the project you're in

That's it. Claude Code is running and ready.

5. Optional: The JetBrains Plugin (~8:00)

After logging in, Claude Code might prompt you to install the JetBrains Claude Code plugin. You can install it if you want — it adds a UI panel inside WebStorm for interacting with Claude Code visually.

That said, most of what we'll do going forward will be typed directly into the terminal. I find you get a better experience and more control that way, so I'll be teaching from the terminal throughout. But it's available if you want it — you can click the link Claude provides and it'll walk you through the plugin installation.

6. Try It Yourself

Verify the Installation End-to-End

Work through these steps in order:

1. Open your WebStorm terminal (Cmd/Alt + E → Terminal)
2. Run the install command for your OS (see Section 3 above)
3. Confirm installation with claude --help
4. Run claude auth login and complete the browser auth flow
5. Run claude in your project directory and confirm the welcome screen appears

What success looks like: You see the Claude welcome screen with your name, your subscription level (Claude Pro), and your project name.

Now try this: Type a simple message to Claude Code — something like hello, what files do you see in this project? — and see how it responds. This confirms Claude can actually read your project, not just that the installation ran.

7. Watch Out For These

8. Practice

Exercise 1: Get Installed and Running

What to do: Complete the full installation and authentication flow for your operating system. Verify with claude --help, then log in and confirm the welcome screen.

A nudge if you're stuck: Most issues at this step come from either (a) the terminal not picking up the new PATH, or (b) the browser not being logged in before the auth step. Check both of those before anything else.

How you'll know it's working: You see the Claude welcome screen showing you're logged in as Claude Pro, with your project name visible.

Exercise 2: Say Hello

What to do: Once Claude Code is running, type a message and see what comes back. Try: what does this project contain so far?

What this is practising: Getting familiar with how Claude Code's conversational interface works inside the terminal. It's different from Claude Desktop — you're inside the project, and Claude can see everything.

9. You Should Be Able to Build This Now

Here's what you've got now:

• Claude Code installed and running inside your WebStorm terminal
• Authenticated with your Claude Pro account — no API key needed
• A working agentic coding environment sitting inside your actual project

Check Yourself

• claude --help returns a list of commands
• I've completed the auth flow and seen "Login successful"
• Running claude in my project directory shows the welcome screen with my name and Claude Pro status
• I've sent a test message and Claude responded correctly

If Something's Not Working

The Short Version

Here's what I want you to walk away with:

• Claude Code is an agentic coding tool — it runs inside your terminal, inside your project, and can read and write your codebase directly. It's not a chat window; it takes real action.
• One command installs it — curl -fsSL https://claude.ai/install.sh | bash on Mac/Linux; the PowerShell command on Windows. No Node.js required.
• Windows users: two valid options — the native PowerShell installer is the simplest. WSL is great if you want a full Linux development environment.
• Authenticate with your Claude Pro account — run claude auth login, go through the browser, done. No API key.
• What you can do now: Claude Code is ready to go. In the next lesson we're going to put it to work.

Quick Reference

Install Commands

# Mac / Linux / WSL
curl -fsSL https://claude.ai/install.sh | bash

# Windows (PowerShell — native installer)
irm https://claude.ai/install.ps1 | iex

Verify Installation

claude --help

Authenticate

claude auth login

Open Claude Code in Your Project

claude

Clear the Terminal

clear
# or on Mac: Ctrl + L
# or in WebStorm: Ctrl + L

Resources

Links & Docs

• Claude Code — official download — always check here for the latest install command
• Claude Code docs — official documentation
• Comprehensive Guide to Setting Up Claude Code on Windows Using WSL

Tools Used

• Claude Code
• WebStorm by JetBrains

Questions I Get Asked

Q: Do I need a separate Claude API key for Claude Code?

No — and this trips people up. Claude Code authenticates via your Claude Pro subscription, the same account you use at claude.ai. Run claude auth login, it opens your browser, you authorise it, done. You don't need to generate an API key from the console.

Q: Can I use VS Code instead of WebStorm for the terminal?

Yes. VS Code has a built-in terminal too — open it with Ctrl + ` (backtick). Everything I'm doing in the WebStorm terminal maps directly across. The terminal is just a terminal; which editor it lives in doesn't matter.

Q: Does Claude Code cost extra on top of my Claude Pro subscription?

No. Claude Code is included in your Claude Pro plan. That's why I recommend authenticating with your Pro account rather than using API credits — you get the same model without paying per token.

Q: How do I know I'm ready for the next lesson?

If you've seen the welcome screen with your name and Claude Pro status after running claude, you're ready. That's the bar.

💬 Stuck? Come Talk to Us

Glossary

Claude Code: Anthropic's agentic coding tool. It runs in your terminal, inside your project folder, and can read files, write code, run commands, and work through tasks autonomously. Unlike Claude Desktop, it doesn't need to reach into your editor via MCP — it's already inside the project. (first introduced in Module 3, Lesson 3)

Agentic (coding tool): A tool that takes action on your behalf rather than just giving you advice. An agentic tool can make changes, run commands, and work through multi-step tasks without you acting as the intermediary at each step. (first introduced in Module 3, Lesson 3)

WSL (Windows Subsystem for Linux): A feature in Windows 10/11 that lets you run a full Linux environment alongside Windows. For developers on Windows, it provides a Mac-like development experience — tools like Claude Code that require a Unix-based environment work natively inside WSL. (first introduced in Module 3, Lesson 3)

Terminal: The command-line interface where you type text commands that interact directly with your system. In WebStorm, you open it with Cmd + E (Mac) or Alt + E (Windows) and selecting Terminal. It's where Claude Code lives. (first used in Module 3, Lesson 1)