Made by Chris Downs · chris@datadowns.com
You need an account and an API key. The API key is what lets the apps you build talk to Claude's brain.
An API key is a secret password that connects your app to Claude. When your app needs to think — understand a question, generate a response, make a decision — it sends a request to Claude's servers. The API key proves your app has permission to do that.
You'll paste this key once when you first set up Claude Code. After that, everything happens automatically — you won't need to think about it again.
Open TextEdit (or Notes), paste your key in, and save the file somewhere you'll remember — something like API Keys.txt on your Desktop.
This is worth doing properly because:
You get free credit to start. For learning projects, this goes a long way.
Claude Code will ask for this key the first time you run it. Just paste it in and press Return.
Software that Claude Code needs to work. You install it once and forget about it.
node --versionTo verify, you'll need Terminal — which we cover in the next section. Come back and check this after Step 1.
Press ⌘ + Space, type Terminal, press Enter. A window opens with a blinking cursor waiting for commands.
You can't click to position the cursor. Navigate with ← → arrow keys. Delete with backspace, one character at a time.
Tab autocomplete: Start typing a folder or file name and press Tab. Terminal finishes it for you. Use this constantly.
Your work needs to live in a folder on your Mac — not in iCloud. iCloud syncing causes problems with these tools.
If your files are in iCloud (Desktop or Documents), Claude Code and git will behave unpredictably. Create a folder outside iCloud.
How: Open Finder → Go → Home. Create a folder called Projects. This is where everything goes.
Now create a project subfolder inside it. Back in Terminal:
cd ~/Projects
mkdir my-first-agent
cd my-first-agent
You now have an empty project folder. This is where Claude Code will build your app.
Claude Code runs in your Terminal. You type what you want, it writes the code.
npm install -g @anthropic-ai/claude-code
claude
If you see a popup asking to install "Command Line Tools" or "Xcode", click Install. This is normal on a fresh Mac and can take 10-20 minutes. It only happens once.
Claude Code will ask for your Anthropic API key on first launch. Paste the key you saved earlier and press Return.
Open a new Terminal window (⌘ + N), then type these two commands:
cd ~/Projects/my-first-agentclaudeThat's it. You're in Claude Code, ready to build.
In Workshop 2, you'll learn how to save your code online with GitHub and put your agent on the internet so other people can use it.
You can't click to move the cursor. Use ← → arrow keys. Backspace to delete.
Tab autocomplete. Start typing a name, press Tab. Terminal finishes it.
↑ arrow = previous command. Cycles through your command history.
Passwords are invisible. When Terminal asks for your Mac password, type it and press Enter — nothing appears on screen, but it's working.
Everything above was preparation. This is where it gets interesting — choose an agent and bring it to life.
Feed it your notes and writing. Ask it questions about your own thinking.
It asks you questions to capture and organise your knowledge.
A thinking partner that knows your context and pushes back.
Takes something complex and makes it accessible to a specific person.
Monitors a topic and surfaces what matters, filtering the noise.
A custom persona — a mentor, historical figure, or fictional advisor.
You might start wanting to build an archivist, then realise everything you know is in your head, not on paper. So you flip the brief to an interviewer instead. Same instinct, different agent. Start with what feels right and let the process teach you what you actually want.
Open Claude Code (type claude in Terminal from your project folder). Paste the brief you copied from the agent card into the › prompt.
Each brief already asks Claude Code for a plan before building. Read the plan, ask about anything you don't understand, then approve it:
That looks good. Go ahead and build it.
Without a plan, Claude Code makes dozens of decisions you don't see. The plan surfaces those decisions so you can steer before anything gets built.
Once Claude Code finishes building, exit it by typing /exit — then run the app on your own machine:
npm run dev
When you see something running in your browser — that's your agent.
When you see an error — and you will — don't panic. Copy the error message, paste it back into Claude Code, and say "I got this error, can you fix it?" This is completely normal. Even experienced developers spend most of their time fixing errors.
Use the app, notice what's wrong or missing, go back to Claude Code and describe changes in plain English:
The tone is too formal. Make it conversational.
When it doesn't know something, it makes things up. I want it to say it doesn't know instead.
Add a way to save conversations.
Claude Code can look at what you've built and tell you what's working and what isn't. It's like having a second pair of eyes.
Look at what we've built so far. What would you improve? What feels rough or unfinished?
If Claude Code just built something and you have no idea how it works — ask. It'll walk you through it in plain English.
Explain what you just built like I'm a complete beginner. What are the main parts and how do they fit together?
When you see an error, don't try to understand it. Just copy the whole error message, paste it in, and let Claude Code handle it.
I got this error: [paste the error]. Can you fix it?
You don't need to know CSS or design terminology. Describe what you want it to feel like and Claude Code will figure out the rest.
The design feels generic and boring. Make it feel more like a luxury brand — clean, minimal, lots of white space, elegant typography.
Describe what you want it to do, not how to build it. Claude Code turns your ideas into working features.
I want users to be able to save their conversations and come back to them later. Add that.
You don't always need to give instructions. Sometimes just describe a problem and let Claude Code help you think through it.
I'm not sure whether this should be one page or multiple pages. What are the trade-offs? What would you recommend?
Talk to Claude Code the way you'd talk to a smart colleague. You don't need special commands or technical language. If you can describe what you want in a sentence, Claude Code can usually do it.
If you hit a wall at any point — something doesn't install, Claude gives you an error, or you just don't know what to do next — get in touch. I'll respond.
chris@datadowns.com