Database / Supabase Intermediate to Advanced Interview Questions

What is the difference between a custom access token hook and a raw JWT claim?

A raw JWT claim is simply a key-value pair Supabase Auth includes in every issued token by default — things like the user's ID (sub), role, and expiry, generated the same way for every user with no customization point.

A custom access token hook is a function (Postgres or Edge Function) that Supabase Auth calls right before issuing a token, letting you inject additional claims based on your own data — for example, looking up a user's subscription tier or organization ID and adding it to the JWT so that value is available to Row Level Security policies and the client without an extra database round trip on every request.

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What does a custom access token hook let you do that default claims don't? Disable Row Level Security globally

✗ Try again, that's not it.

Bypass the need for sign-in entirely

✗ Try again, that's not it.

Delete a user's account automatically

✗ Try again, that's not it.

Inject additional claims based on your own application data

✓ Correct! Well done.

When is the access token hook invoked? Right before Supabase Auth issues a token

✓ Correct! Well done.

Once a year during a scheduled job

✗ Try again, that's not it.

After the JWT has already expired

✗ Try again, that's not it.

Only when a user deletes their account

✗ Try again, that's not it.

More Related questions...

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