Fix · Supabase and databases

42501 permission denied for table

Blocks your workNot checked against the vendor's current screens

What you may see

The error is permission denied for table, not row-level security
A table I created by SQL cannot be read from my app

Most likely cause

The database role your app uses (anon or authenticated) has no GRANT on that table, function or schema; this is separate from row level security.

Check first (about two minutes)

Read the word after "for": is it table, schema, function or sequence?
Did you create the table with SQL (not the dashboard buttons)? Then grants may be missing.

The fix prompt

What you type here never leaves your browser. The search runs on this page, and nothing is sent to a server or to an AI.

The exact error or what you see

What you did before it happened

Kept only in this browser, on this device. Keys and passwords are removed before anything is saved.

Prompt language

You are a careful senior engineer who knows Supabase (database, login and file storage) and explains it to people who are not developers. I am not a developer, so explain every step in plain words and tell me exactly which button, menu or command you mean. If you are not sure about something, say so; do not guess.

Menu and button names change over time. If you cannot find a button or page I mention, say so and tell me what to look for instead of guessing.

THE PROBLEM
42501 permission denied for table

THE EXACT ERROR OR WHAT I SEE
[paste the exact error here]

WHAT I DID BEFORE IT HAPPENED
[write in a few words what you did before it happened]

MOST LIKELY CAUSE
The database role your app uses (anon or authenticated) has no GRANT on that table, function or schema; this is separate from row level security.

DO THESE STEPS, IN THIS ORDER
1. Show the grants on the table for the roles anon and authenticated (query information_schema.role_table_grants).
2. Decide with me the minimum each role needs (for example authenticated: select, insert; anon: nothing).
3. Write the GRANT statements for exactly those, as a migration file, together with the row level security policies so the rows stay protected.
Stop and tell me if what you see does not match a step. Do not skip ahead.

CHECK THAT IT WORKED
- The call from the app works, and an anonymous call still cannot read private rows.
Tell me exactly what I should see on the screen when it works.

DO NOT CHANGE
- Do not grant everything to anon.
- Anything I did not ask about: the design, the text, other pages, other settings or the data.
- Do not delete files, data or branches, do not reset or force-push, and do not rewrite history, unless you first show me exactly what would be lost and I say yes.
- Do not paste, print or ask me to paste a password or secret key into this chat. If one is needed, tell me which settings page of the right service to store it in.

WHEN YOU FINISH
Explain in simple words what you changed (file by file or setting by setting), why you changed it, and how I can undo it.

Paste it into Claude, ChatGPT, Gemini or Cursor, then follow what it says.

After you tried it, did it work?

Steps

Show the grants on the table for the roles anon and authenticated (query information_schema.role_table_grants).
Decide with me the minimum each role needs (for example authenticated: select, insert; anon: nothing).
Write the GRANT statements for exactly those, as a migration file, together with the row level security policies so the rows stay protected.

Do not do this

Do not run GRANT ALL on private tables for anon "to test".
Do not grant everything to anon.

Try another entry