How to secure a Lovable app before you launch

Why Lovable apps need a check before launch

Lovable builds a React front end on top of a Supabase database. The browser talks to the database directly with a public key, so the database rules are the only thing standing between a visitor and every row in every table. When those rules are missing or too loose, anyone who opens the browser’s developer tools can read or change data.

Lovable runs a basic security scan when you open the publish dialog, and offers a deeper code review on demand. Its own documentation says these tools help find common issues but cannot guarantee complete security, and that the basic scan does not look for logic flaws specific to your app.

The checklist

1. Open the Security view in Lovable and run the deep scan, not only the basic scan that runs on publish. Fix every critical item first.
2. In Supabase, confirm row level security is enabled on every table in the public schema, and that each table has policies that tie rows to auth.uid() or to a membership table.
3. Test the policies as an attacker would: request each table through the REST API with only the anon key and no session, and confirm you get an empty result or an error, never other users’ rows.
4. Check storage buckets. A public bucket serves every file to anyone with the URL; make private any bucket that holds user uploads.
5. Move every secret key (Stripe secret, OpenAI, Resend, the Supabase service_role key) into Edge Function secrets. Nothing that starts with sk_ or contains service_role should ever reach the browser.
6. Enforce plans and roles on the server. Hiding a button in React is not access control; the Edge Function or the RLS policy must refuse the request.
7. Take prices from your payment provider’s price IDs on the server, never from an amount the browser sends.
8. Scan the live URL for leaked keys in the JavaScript bundle, exposed files, missing security headers and missing legal pages, then rescan after each fix.

What Lovable’s scan covers and what it does not

Use both: Lovable’s scan sees your database configuration from the inside, Defexity sees the deployed app from the outside the way a visitor or attacker does.

Questions

Is the Supabase anon key a secret?

No. It is designed to be public and ships in every Supabase front end. It is only safe because row level security limits what it can do, which is why RLS on every table matters.

Does Lovable’s publish scan make my app secure?

It catches common database and dependency problems. Lovable recommends running the deeper scan before launching or handling user data, and a professional review for sensitive data.

Can I scan a Lovable app I do not own?

Only run scans on apps you own or have permission to test. Defexity’s public scan is read-only, but you should still have the owner’s permission.

Related Defexity checks

• SEC-016: Secret key exposed in public HTML or JavaScript
• SEC-012: Environment file publicly accessible
• SEC-046: Firebase Realtime Database is publicly readable
• SEC-047: Firebase Storage bucket can be listed by anyone
• SEC-005: Content-Security-Policy missing or permissive
• PRV-001: No privacy policy link

Sources

• Lovable docs: Security (opens in a new tab)
• Supabase docs: Row Level Security (opens in a new tab)