Lovable Supabase RLS & Permission Errors, Fixed

Why does my form say success but nothing saves to Supabase?

When a Supabase insert or update silently fails — the UI shows no error but the row never appears in the table — the almost universal cause is a Row Level Security policy that blocks the write. Supabase RLS does not throw a visible error by default; it simply returns zero affected rows, which the Lovable-generated front-end often interprets as a success. The data is being rejected at the database level, not the application level.

To confirm: open the Supabase dashboard, navigate to your table, and check the RLS policies tab. If INSERT or UPDATE policies are missing or misconfigured for the authenticated role, writes will silently fail. Temporarily disabling RLS on the table (never in production, only in development) can confirm the diagnosis instantly.

The silent failure happens because Supabase returns an empty result set (not an error) when RLS blocks a query. Lovable-generated code typically checks for a non-null response to indicate success — and an empty array is non-null. This is the cause of the 'form says success but nothing saves' symptom — one of the most widely reported pain points in Lovable-built apps.

What causes 'Infinite recursion detected in policy' in Supabase?

The exact error string `ERROR: infinite recursion detected in policy for relation "your_table"` appears when an RLS policy references the same table it is protecting. A SELECT policy on a profiles table that queries profiles to check admin status creates an infinite evaluation loop — Supabase must evaluate the policy to allow the query, but evaluating it requires running the query. The entire table becomes unreadable until the policy is corrected.

1. Open the Supabase SQL editor and run: SELECT * FROM pg_policies WHERE tablename = 'your_table_name';
2. Look for policies whose definition contains a subquery referencing the same table.
3. Rewrite the policy to use auth.uid() and auth.jwt() claims instead of a subquery back to the same table.
4. If admin checks are needed, store the role in the JWT claims at sign-in rather than looking it up mid-query.
5. Test the fix by running a simple SELECT in the SQL editor under the affected user role.

Why am I getting 403 errors on authenticated requests?

A 403 from Supabase means the RLS policy explicitly denied the request — not that the policy is missing. Common causes in Lovable-built apps: a policy that checks `auth.uid()` but the request is firing without the Authorization header, or the Supabase client is initialized with the anon key before the user's session has loaded.

Check: is the Supabase client initialized with the correct anon key, and is the user actually signed in before the request fires? In Lovable-generated code, async auth state is sometimes read before the session is loaded, causing the first request to fire as an unauthenticated call even when the user is logged in. The error in the Supabase logs will show `role: anon` instead of `role: authenticated` — that is the diagnostic signal.

Never use the service role key in client-side code. The anon key is the correct credential for browser-facing Supabase clients. The service role key bypasses all RLS — if it appears anywhere in your frontend code or Lovable environment variables that are exposed to the browser, every user effectively has admin access to your entire database.

How do I write correct RLS policies for a Lovable app?

The safest pattern for most Lovable apps is a standard set of policies per table: SELECT, INSERT, and UPDATE each restricted to rows where `user_id = auth.uid()`. This ensures every user can only read and write their own data. For the full CRUD SQL template and advanced patterns like multi-role access, see the reference page linked below.

After writing policies, always test them explicitly. In the Supabase SQL editor, run `SET LOCAL role = authenticated; SET LOCAL "request.jwt.claim.sub" = '<your-test-user-uuid>';` before your query to simulate a real user session. An RLS policy that looks correct can still have a silent gap — a wrong column name, a missing WITH CHECK clause, or a policy that applies to SELECT but not INSERT.

The most common production incident from Lovable apps is not a broken UI — it is an RLS policy that was silently wrong at launch and allowed one user to read another user's data. Fixing that after launch requires more than a code change.

How do I confirm my RLS fix is actually working?

After fixing an RLS policy, verification must happen at the database level — not just in the UI. The UI can show a success message while RLS silently blocks the write. Run this sequence to confirm the fix is genuine.

1. In the Supabase SQL editor, simulate a user session: SET LOCAL role = authenticated; SET LOCAL "request.jwt.claim.sub" = '<user-uuid>';
2. Run the blocked query (SELECT, INSERT, or UPDATE) manually and confirm it returns the expected result.
3. In the Supabase dashboard, navigate to the table and confirm the row you inserted actually appears.
4. Sign in as a test user in your app and trigger the previously-failing action.
5. Check the Supabase logs (Database → Logs) to confirm the request shows role: authenticated, not role: anon.
6. Test as a second user and confirm they cannot read or write the first user's rows.

When should I get a senior engineer to review my RLS setup?

RLS mistakes are invisible in the UI and can create serious security vulnerabilities — data leaks between users, admin-only actions available to everyone, or entire tables locked by a recursive policy. If your app handles any sensitive data, financial information, or user-generated content, an RLS review before launch is strongly advised.

A senior engineer can audit your full policy set, identify gaps, and write a test suite that verifies each policy independently. The most critical check is whether any user can read another user's rows — this is the most common RLS failure mode in Lovable-generated apps and is often invisible to the builder.