Is it safe to expose the Supabase anon key?
Yes, the Supabase anon key is designed to be public. It ships in the browser on purpose so your frontend can talk to the database. Exposing it is not the mistake.
The mistake is exposing it without Row Level Security. The anon key obeys your table policies. If a table has RLS on with proper policies, the key can only read what those policies allow. If a table has RLS off, the same key can read the entire table, and now that public key is effectively a key to your data.
So the honest answer is: the anon key is safe to expose only when every table has Row Level Security and policies. The way to know is to test it, by sending an anonymous read to your tables and seeing what comes back.
Check whether your anon key is exposing data
What it means
Your database tables can be read by anyone, not just logged-in users. Someone could open your app's data — customer emails, orders, private records — without ever creating an account.
Why AI tools cause it
Supabase only protects a table once you turn on Row Level Security (RLS) and write access rules for it. AI tools frequently build a working app without doing that, so the tables are wide open by default.
How xlogs checks it
xlogs finds your public Supabase URL and anon key in your app (the same ones your frontend uses), asks the database as an anonymous user which tables it can read, and flags any that return real rows. Read-only: it never writes or deletes.
How to fix it
The goal: Row Level Security is enabled on every table, with policies so a table only returns rows to users allowed to see them; no table returns private data to an anonymous request.
- Enable Row Level Security (RLS) on every table, especially the affected spot
- Add a policy per table so only authenticated users can read/write their own rows (keep intentionally-public tables public on purpose)
- Re-check that an anonymous request no longer returns private rows
In my app (the spot the scan shows): anyone can read this database table. Please make this true: Row Level Security is enabled on every table, with policies so a table only returns rows to users allowed to see them; no table returns private data to an anonymous request. Steps: Enable Row Level Security (RLS) on every table, especially the spot the scan shows; Add a policy per table so only authenticated users can read/write their own rows (keep intentionally-public tables public on purpose); Re-check that an anonymous request no longer returns private rows. Then tell me exactly what you changed, and do not print any secret values back to me.
Then verify: After you deploy the policies, xlogs repeats the same anonymous read test and confirms the table no longer returns data without a login.
Full step-by-step fix guide, with a copy-paste block for each AI tool →
Common questions
What is the difference between the anon key and the service key?
The anon key is public and obeys your RLS policies. The service_role key ignores RLS and can do anything, so it must never ship to the browser. If a service key is exposed, treat it as an emergency and rotate it.