What exactly should you do when your JWT has expired? How do you go about fetching a new one? EDIT: There's an undocumented method called refreshAccessToken, but how would I go about detecting that my current JWT has expired, so i can refresh my JWT silently?

If you decode it, you can see when it is going to expire

how would i go about actually refreshing the token though? aka how do I know that I should refresh my token? ex: the JWT would expire in 15 mins, how would I refresh it before then

If you use supabase js, it handles by itself

but it would error out randomly that my jwt is expired every now and then

Hmm, Im not sure. I never received an error for the expired token using supabase-js

do you also set an auth cookie? could that have something to do?

I dont. I use it directly from frontend