permission denied for table (Supabase error 42501)

What it means in plain English

Postgres checks two things: does this kind of user have permission to touch the table at all (a 'grant'), and then which rows (RLS). This error means the first check failed.

Likely causes

• The table was created without grants to anon/authenticated (newer projects may not grant automatically).
• Grants were revoked.
• Table in a schema not exposed to the API.

How to fix it, step by step

1. In SQL Editor, grant only what's needed, e.g.:

grant select, insert, update, delete on table public.reports to authenticated;

2. Make sure RLS is enabled and policies exist for each operation.
3. Supabase advises checking grants before changing policies when a request that should be allowed fails.

How to check it worked

• The request now returns data (or an empty list if no policy matches; then see the RLS page).

Sources

• https://supabase.com/docs/guides/database/postgres/row-level-security (opens in a new tab)
• https://supabase.com/docs/guides/api/api-keys (opens in a new tab)