Your Toolkit — Part 4: Your First AI-Built Mini-App

maang.io AI-Native Builder Series

📦 Artifacts for this topic — build against these, and check your own with them:
set up your tools → artifacts/setup.md (terminal, editor, Git/GitHub, AI partner) ·
the mini-app prompt → artifacts/prompts/01-day-counter-mini-app (copy it into your AI tool) ·
check your work → artifacts/verify.md.
Build yours first, then compare — the reference is a mentor's version to verify
against, not an answer key to paste.

What is this?

Before a pilot ever flies passengers, they do a first solo — a short, safe, complete flight. Take off, circle the field, land. It's not a long journey and there are no passengers aboard, but it's the whole thing in miniature: every system, in the real cockpit, for real. After it, you're not just someone who read about flying. You've flown.

This chapter is your first solo. You've met all four tools separately — the terminal, the editor, Git/GitHub, and your AI partner. Now you'll fly them together to build a tiny but complete app, end to end, by running the Build Loop the whole way around: understand → design → prompt → review & verify → test → commit. The app is deliberately small — a "Day Counter" that shows how many days you've kept a streak. The point isn't the app. The point is that you'll have directed an AI to build real, working software, understood every part of it, and saved it to GitHub — the exact motion you'll repeat all summer on StreakUp, just scaled up.

The one-line idea: you'll build one tiny real app by running the full Build Loop once, so the process — not the app — is what you walk away owning.

Let's take off. We'll go step by step around the loop, and you'll do it for real as we go.