How to enable Row Level Security on Supabase

Step by step

1. 1

   Turn on RLS for every data table

   In the Supabase dashboard, enable Row Level Security on each table. Once enabled with no policy, access is denied by default — exactly what you want.

2. 2

   Add a SELECT policy scoped to the user

   Create a policy like CREATE POLICY "own rows" ON your_table FOR SELECT USING (auth.uid() = user_id);

3. 3

   Repeat for INSERT / UPDATE / DELETE

   Each operation needs its own policy. Use WITH CHECK on writes to stop users from writing rows they shouldn't own.

4. 4

   Test both authenticated and anonymous access

   Confirm an anonymous request returns nothing and an authenticated user sees only their own rows.