Build your idea

You have a spec. You know what you're building, who it's for, and what "done" looks like. Now comes the moment of truth - actually building it.

This lesson is different from the others. It's less about learning concepts and more about doing the work. You'll take your spec from Lesson 6 and turn it into a working app. Along the way, you'll practice the most important skill in building: iterating until it's right.

Start with your spec

Go back to Lesson 6 and copy your completed spec. If you used the worksheet, click "Open in Replit" to launch directly with your spec pre-filled. If you wrote it somewhere else, copy and paste it into Agent's chat.

Your spec is your north star. Every decision you make during the build should tie back to it. When you're tempted to add features or change direction, ask yourself: "Is this in my spec? Does it serve my definition of done?"

Build incrementally

Here's a mistake new builders make: they paste their whole spec and expect perfection on the first try. That's not how building works. Even with AI, creating something good takes multiple passes.

Start with the core. What's the one thing your app absolutely must do? Get that working first. If you're building a recipe saver, make sure you can save and view a recipe before worrying about search or categories. If you're building a workout tracker, nail the basic logging before adding charts.

Each feature you add is a chance to test, refine, and make sure the foundation is solid. This is how professional engineers build - one working piece at a time.

The iteration loop

Remember describe-critique-iterate from Lesson 3? This is where it becomes real. After Agent generates something, your job is to:

1. Test it thoroughly. Click every button. Try edge cases. Use it like a real user would.
2. Notice what's off. Too cramped? Wrong color? Missing feedback? Write it down.
3. Give specific feedback. "Make it better" is vague. "Add more padding between cards and change the button color to blue" is actionable.

Most apps take 3-5 rounds of iteration to feel right. Don't get discouraged if the first version isn't perfect - that's normal. Each round gets you closer.

When things go wrong

Something will break. A button won't work. Data won't save. The layout will look wrong on your phone. This is normal - it happens to every builder, every time.

When you hit a problem, describe it clearly to Agent:

• What you expected: "When I click Save, the recipe should appear in my list"
• What happened instead: "The page refreshes but the recipe doesn't show up"
• Steps to reproduce: "Fill out the form, click Save, check the recipe list"

The more specific you are, the faster Agent can fix it. Vague complaints lead to vague fixes.

Stuck on the same issue after several attempts? Try a different approach: ask Agent to explain what's happening, or simplify the feature temporarily. Sometimes the best way forward is to step back.

Publish and share

When your app meets your definition of done - when it does what your spec says it should do - it's time to publish. Click the Publish button in the Workspace. Within seconds, your app will be live with a URL you can share.

This is the moment most people never reach. They plan forever, tinker endlessly, or abandon projects halfway through. By publishing, you've done something most people only talk about: you shipped.

Share it. Post it somewhere. Tell a friend. The feedback you get from real users is worth more than weeks of solo iteration.

What's next?

You've finished AI Foundations. You know what apps are, how AI works, and how to scope and build an idea. That's more than most people ever learn.

But here's the truth: you learn to build by building, not by reading. The lessons ahead will make more sense after you've wrestled with a real project. Your second app will be better than your first. Your tenth will be dramatically better.

So before you continue, go build something. It doesn't have to be big or perfect - it just has to be yours. Come back when you've shipped, and you'll be ready for what's next.