🤔 What Claude Code is — and isn't
Claude Code is not a chatbot with a code block. It's a CLI tool (command-line interface) that you install in your terminal and run inside your project folder. The difference matters enormously.
When you open Claude.ai and paste in some code, Claude sees only what you paste. When you run Claude Code inside your project, Claude can read every file in your project — the HTML, the CSS, the JavaScript, the README, the config files. It has the full context of what you're building before you even say anything.
The mental model shift: A browser chat is a consultant you have to brief every time. Claude Code is a developer who already knows your project and is sitting next to you. The quality of what's possible goes up significantly.
💳 How to pay — API vs subscription
Claude Code can run on two different billing models. Which one makes sense depends on how intensively you use it.
Pay only for what you use. A typical 30-minute session costs $0.10–$0.50. Top up $10–20 at console.anthropic.com and it lasts months for light use.
No monthly commitment. Starts immediately.
Pro ($20 USD/mo) — included Claude Code access with monthly usage limits.
Max ($100 USD/mo) — much higher limits, priority access, ideal for developers using it daily.
No API key needed — logs in with your Claude.ai account.
Practical advice: Start with the API key ($5 credit) to test it. If you find yourself using it daily for real project work, the Pro subscription at $20/month is better value than per-token billing. Max is only worth it if you're doing professional development full-time.
⚡ Installing Claude Code
Claude Code requires Node.js (which you installed in Module 4) and an Anthropic API key.
$ cd my-project-folder
# Start Claude Code — it will ask for your API key on first run
$ claude
Claude Code reads your project, shows you a summary of what it found, and drops you into an interactive session. From here, you just talk to it.
📄 CLAUDE.md — teaching Claude your project
The most powerful thing you can do with Claude Code is write a CLAUDE.md file in your project root. This is a plain text file that Claude reads at the start of every session — before you say anything.
Think of it as the briefing you'd give a new collaborator who's joining your project. You write it once, and every future session with Claude Code starts with Claude already knowing the important things.
Why this is powerful: Every time you start a Claude Code session, it reads this file. You never have to re-explain your project. When you hire a tradesperson, you don't re-explain the house layout every visit — you have a site briefing. CLAUDE.md is your site briefing.
💬 The core workflow
Once you're in a Claude Code session, the conversation is natural — but there are patterns that work better than others:
> Add a hamburger menu to the nav — mobile only, hamburger icon at 768px and below
# Fixing something that broke
> The contact form stopped submitting — check form.js and contact.html and find what's wrong
# Understanding existing code
> Explain what the booking.js file does, section by section
# Adding features with context
> Looking at how the events page works, add a similar gallery page for the menu items
# Reviewing before committing
> What did you just change and why? Show me a summary before I accept it
Claude Code will show you the changes it wants to make and ask for your approval before writing to any file. You can accept, reject, or ask it to do something different. You are always in control of what gets written.
The most important habit: Read what Claude Code proposes before accepting. Not because it's usually wrong — but because understanding what changed is how you learn. Accepting blindly is fine when you're in a hurry; reading carefully is how you build real skill.
⌨️ Slash commands and power tips
Once you're inside a Claude Code session, these commands and habits make a significant difference:
Keep sessions focused: Claude Code is most accurate when working on one clear task at a time. If you have three unrelated things to do, do them in three separate exchanges (or /clear between them). A 5-hour session with 100 different topics will drift — a 30-minute session with one clear goal won't.
The review habit: Before accepting any change, ask: "Show me what files you changed and why." This takes 10 seconds and teaches you far more than blindly accepting. After a few sessions of this, you'll start anticipating what Claude will do — which is when you level up from user to collaborator.
⚖️ Claude Code vs Cursor vs ChatGPT — when to use which
These tools overlap, but each has a clear home:
- Claude Code — best for working on a project you already have. Full codebase context. Makes targeted edits. Great for debugging, adding features, understanding complex code. Requires terminal comfort. Pay-per-use.
- Cursor — the best agentic IDE for starting new projects from scratch or vibe coding with a visual interface. Has its own built-in AI that works similarly to Claude Code but with a GUI. Good first choice for Module 5-style builds.
- ChatGPT / Claude.ai browser — best for isolated questions, learning, writing tasks, and working without a project context. No files, no context — but zero setup.
Practical flow: Use Cursor or Bolt.new to build the first version. Once you have a working project, switch to Claude Code for ongoing work and maintenance — because it understands what you've already built.
👇 Write your first CLAUDE.md
Open your Module 5 or 6 build. Create a new file called CLAUDE.md in the root of the project folder. Write it like you're briefing a new collaborator. Include:
- What this project is — one sentence
- Tech stack — what files and languages are involved
- Key decisions — things that should stay the same (colours, fonts, structure)
- Things not to do — what you don't want changed
- Current work — what you're working on right now
Then if you have Claude Code installed: run claude in that folder and watch it read your briefing. Ask it a question about your project. Notice the difference.
Even if you don't have Claude Code installed yet: writing the CLAUDE.md is the exercise. It forces you to articulate what your project is — which is useful regardless of the tool.
Branch complete 🤖
Claude Code is the clearest expression of what AI-assisted development actually looks like at the frontier. Not a chat window with code in it — an AI that lives inside your project and works with you on it.