Fetching data *once* and storing it in session

[nkalupahana]

When a user signs in, I'd like to fetch some sensitive information about them from a database (note: expensive operation) and store it in their server-side session. That way, in future requests (for the whole duration they're signed in), we can get that data directly from the user's session instead of having to do that expensive operation every time.

How would you go about doing this with next-auth's sessions? I tried putting the data in the jwt callback, but that callback seems to get called every time a page is loaded, so that expensive operation gets repeated constantly. I just want it to be run when the user signs in, stored, and then never again.

[balazsorban44]

If you need to add something only at the beginning of a session, check out the docs:

https://next-auth.js.org/configuration/callbacks#jwt-callback