Setup

At the start of this lesson, copy the bundled lesson support files into the workspace if they are not already present. Briefly tell the student what files are available if you mention them during the lesson.

cp -rn .agents/skills/start-3-3/assets/* . 2>/dev/null || true

Teaching Rules

Follow the course teaching rules in .agents/skills/_shared/teaching-rules.md. In short: follow the lesson script in order, speak naturally, stop at each STOP/CHECK point, and do not break the fourth wall.

3.3 Build & Iterate

This is it. Time to build your quiz.

I'm going to handle all the technical setup. You just watch the magic happen.

STOP: Ready?

USER: Yes

First, I need to set up the project structure - this creates all the starter files we need.

ACTION: Run the following command in quiz-project/:

npx create-next-app@latest . --typescript --tailwind --eslint --app --no-src-dir --import-alias "@/*" --yes

(The --yes flag accepts all defaults automatically)

Done! Open Files and look inside:

quiz-project/

You should see a bunch of new files there. Don't worry about understanding all of them. The quiz-project/app/ folder is where your quiz will live. Everything else is just configuration.

STOP: Do you see the new files?

USER: Yes

Before I build, let me show you something useful: plan-first workflow.

For big tasks, it helps to see what I'm going to do before I do it. In Codex, you can ask me to propose a plan first, review it, then approve execution.

STOP: Ready to have me plan before building?

USER: Ready

Perfect. I'll show you my plan, you approve it, then I execute. Let's do it.

STOP: Ask me to build the quiz based on the requirements.

USER: Build my quiz based on quiz-project/REQUIREMENTS.md

ACTION: Read quiz-project/REQUIREMENTS.md, then create a plan showing:

• Components to create (quiz page, question component, results page)
• Styling approach based on their chosen style
• Quiz logic implementation (how answers map to results)
• Any images/icons to include

Present the plan clearly with bullet points.

Here's my plan. I'll create the quiz page, the question components, the results page, and style everything according to your preferences.

STOP: Does this look right? Any questions before I start?

USER: Looks good / [Questions]

ACTION: Answer any questions they have, then ask for approval to execute the plan.

Building now. This takes a minute or two. You'll see me creating and editing files. Just let me work.

ACTION: Build the full quiz application based on quiz-project/REQUIREMENTS.md:

1. Create the main quiz page in quiz-project/app/page.tsx
2. Create quiz components (QuizQuestion, Results, etc.)
3. Implement the quiz logic (tracking answers, calculating results)
4. Apply the visual style they chose
5. Add any images/icons based on their preference
6. Make sure the result display matches their choice (single vs percentages)

Take your time and build it properly. This is the core deliverable.

Done! Your quiz is built. Now let's see it in action.

I'm going to start your quiz running and open it in your browser.

ACTION: Run npm run dev in background in quiz-project/

ACTION: Wait a few seconds for the server to start, then open http://localhost:3000 if browser opening is available, otherwise ask the student to open it manually in browser

Your quiz should now be open in your browser:

http://localhost:3000

This "localhost" link only works on YOUR computer - it's a temporary local version. We'll make it public later when we deploy.

STOP: Do you see your quiz?

USER: Yes! / [Issues]

ACTION: If they have issues:

• Browser didn't open → Tell them to manually go to http://localhost:3000
• Build errors → Check the terminal output, fix errors
• Blank page → Check for JavaScript errors in browser console

Look at that! You have a working quiz!

Take it for a spin - answer the questions and see your result.

STOP: Try the quiz. Does it work? Do you get a result at the end?

USER: Yes it works! / [Something's wrong]

ACTION: If something's wrong, debug together. Common issues:

• Result not showing → Check the logic implementation
• Wrong personality mapping → Review the answer mappings
• Style issues → Can fix in iteration

This is normal - first versions often need fixes. Let's get it working first, then polish.

Amazing! You just built a web app. Let that sink in.

The first version is never perfect. Let's iterate - make 2-3 changes until you love it.

Here's a trick: you can take a screenshot, attach it, drag it into the chat, or paste it here, then tell me what to change.

Circle something, point at it, whatever - just show me what you want different.

This is also a great way to show me bugs. If something looks wrong, screenshot it and paste it here.

If you're not sure what to change, here are some ideas:

• Add confetti or animation when you get your result
• Change the colors or fonts
• Tweak the wording on questions or results
• Add images for each result
• Change the layout or spacing
• Add a progress bar

STOP: Take a screenshot of your quiz, attach or paste it into chat, and tell me what you'd like to change.

USER: [Pastes screenshot and describes change]

ACTION: Make the requested change to the code

Done! Refresh your browser to see the update.

STOP: How's that? Want to change anything else?

USER: [More changes / Happy with it]

ACTION: Keep iterating until they're satisfied. 2-3 rounds is typical. Common requests:

• Visual tweaks (colors, spacing, fonts)
• Animation additions
• Wording changes
• Layout adjustments

Look at that - it's YOUR quiz, exactly how you want it.

This is the iteration loop: screenshot → describe → change → refresh → repeat.

This is how real product development works. And with AI, each iteration takes seconds instead of days.

STOP: Happy with how it looks?

USER: Yes

What you just learned: How to go from requirements to working product, then iterate until it's exactly what you want.

Where else this applies:

• Building any web project - landing pages, tools, prototypes
• Testing ideas quickly before investing in "real" development
• Working with designers/developers - clear visual feedback speeds everything up

Next up: In 3.4, we save your code to GitHub. Right now it only exists on your computer. We're going to put it in the cloud so it's backed up and ready for deployment.

STOP: Ready to save your work? Say "let's do GitHub" or type /start 3 4

USER: Let's do GitHub

Important Notes for Codex

• The npm run dev command should run in background so the user can keep talking
• localhost:3000 is the default Next.js port - if something's already using it, Next.js will suggest another port
• When they paste screenshots, actually look at them and make specific changes
• In Codex Desktop App, screenshots can be attached, dragged into chat, or pasted
• Keep iterations focused - don't suggest too many changes at once
• If the quiz has bugs, fix them before moving to visual polish
• The plan-first workflow matters: show the plan, wait for approval, then execute

Success Criteria

• Next.js project is scaffolded in quiz-project/
• Quiz is fully built based on quiz-project/REQUIREMENTS.md
• Dev server is running and quiz is viewable at http://localhost:3000
• User has done at least 1-2 iterations
• User is satisfied with how their quiz looks
• User is ready for GitHub