GPT-6 Astra is insane. It’s been a minute since we’ve used AI to build an app from scratch, so I figured we’d start one today!
You can use Astra in many AI-coding assistants. Today’s tutorial will use Codex, but you’ll have a similar experience in Cursor and OpenCode.
I did my project scoping, planning, and implementation of MVP in less than one hour, all without hitting usage limits on the OpenAI $20/mo plan. Read on to see how.
What we’re going to use AI to build #
Lately I’ve been wishing there was a good, minimal app to keep track of home maintenance and projects. There’s a few decent options already, but nothing that fit what I was looking for perfectly.
But since we’re in the middle of “the decade of agents,” I could just build exactly what I wanted.
Here’s the landing page for Hearth, the home maintenance SaaS that I built with GPT-6 Astra in Codex.
Astra helped me plan, design, architect, and build the entire app. It’s a React app with Stripe & Cloudflare, and I’ll show you how I used AI to do the whole thing.
If you want to use AI to build your own apps, you’re obviously in the right spot. I spend dozens of hours researching each of these guides so you have a shortcut to building software with AI. I’d love to have you join us and get notified when we share more tutorials like this.
Planning out the project in plan mode #
When I first started using AI to build software, I perceived it to be a bit dumb, because it was! You can look at tutorials from last year and see that I give explicit advice to not start using AI until you know exactly what you want.
I won’t give that advice anymore.
As we move towards intelligence too cheap to meter, it becomes more and more reasonable to let AI make tons of the decisions.
The advice I give in Using AI to Plan a New App is still worthwhile. If you know exactly what you want, you should give explicit instructions, maybe even a PRD. You can even use AI to help you draft your PRD, and you’ll still get more reliable results.