Row-Level Security is the single most important layer in a Supabase deployment. AI tools almost never configure it correctly. This is what a broken RLS policy looks like in production, and how we audit and patch it before your data is exposed.
Row-Level Security is Supabase's mechanism for enforcing data access control at the database level. It determines which rows a given user can read, write, update, or delete. When configured correctly, it is a powerful and elegant security layer. When configured incorrectly — or not configured at all — it is one of the most dangerous vulnerabilities a production application can have.
AI-generated Supabase backends almost universally ship with RLS disabled or misconfigured. The reason is straightforward: enabling RLS and writing correct policies requires understanding the application's authentication model, user roles, and data ownership patterns. That understanding requires reading the whole system. AI tools generate components in isolation. They do not reason about the whole system.
The most common failure mode we encounter is a database with RLS enabled but no INSERT policy on a table that the application writes to. The app crashes on any form submission. The developer disables RLS entirely to make it work. The application now runs — and every row in every table is readable and writable by any anonymous request.
The second most common failure is an overly permissive SELECT policy. A policy written as `using (true)` allows any authenticated user to read all rows regardless of ownership. In a multi-user application, this means every user can read every other user's data. The application appears functional. The data exposure is invisible until someone looks.
Correct RLS policy design starts with a clear ownership model: every row belongs to a user, and users can only access their own rows unless explicitly granted access to others. The service role key — used only on the server side — bypasses RLS entirely, which is correct for administrative operations. The anon key — which must never appear in client-side code — maps to the anonymous role and should have minimal permissions. Every policy we write is tested against both authenticated and unauthenticated requests before handoff.
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