Your notes app has real users. Sign up, log in, see only your own data — it all works. But hand the URL to a friend and two things break: there's no Google login button, and verification emails go to a terminal they can't see.
This chapter closes both gaps. You'll leave the code editor and spend most of your time in dashboards — Google Cloud Console, GitHub Developer Settings, Resend, Turso, and Vercel. The code is already in the starter. Your job is to connect it.

Up to now, every chapter has been about building features — routes, forms, database tables, user accounts. This chapter is different. You won't write much code. Instead, you'll configure external services and wire them into your app with environment variables.
Each integration adds something visible and testable. The Google button appears. The GitHub button works. A real email arrives in your inbox. The deploy page is the victory lap.
?What is OAuth?By the end, anyone with a browser can sign up for your app — with Google, GitHub, or email — and receive real verification emails. Let's start with Google.