Authentication + per-user data

LESSONLesson 3 · ~20 min

🎯Goal. Add login so each person sees only their own tasks — a real multi-user app.

▶ Try this prompt

Add email and Google sign-in. Each user should only see and edit their own tasks. Show a login screen to logged-out visitors.

Lovable configures authentication (via Lovable Cloud / Supabase Auth) and wires per-user data access for you.

1Send the prompt above. Lovable adds signup/login and protects the app's routes.
2Sign up as two different users and confirm each sees only their own tasks — that's row-level ownership working.
3Check that a logged-out visitor lands on the login screen, not the app.

✓You'll see. A working multi-user app where data is correctly scoped per signed-in user.

💳Cost. Auth is part of the built-in backend; the build prompt consumes credits like any chat change.

💡Takeaway. Auth + per-user data — the backbone of any real app — is a single well-scoped prompt in Lovable.