How to use JWT to store data in NextAuth - json

Question

I return the following JSON after confirming credentials:
{username: 'foo', name: 'bar', type: 123}
However, NextAuth does not allow me to store all the fields due to model limitations, so what it returns in JWT to client is:
{name: 'bar', email: null, image: null}
My [...nextauth].js setup is very basic:
providers: [
Providers.Credentials({
async authorize(credentials) {
const res = await fetch('http://localhost:3000/api/user', {
method: 'GET',
headers: {
'Accept': 'application/json',
'Content-Type': 'application/json',
'credentials': JSON.stringify(credentials)
}
})
const user = await res.json()
if (user && !user.message) {
return user
} else {
return null
}
}
})
],
The only solution I came up with is to fake email field with JSON string in which I can store everything I need:
{name: 'bar', email: "{username: 'foo', type: 123}", image: null}
How can I do it properly? I tried looking into custom models (https://next-auth.js.org/tutorials/typeorm-custom-models), but it seems to be only about databases, which is not my case since I use JWT for session storage.
Also what drawbacks I can encounter if I continue with my solution?

Answer 1

You will need to persist the additional info through callbacks, at first through JWT's callback and then Session's callback:
callbacks: {
async jwt(token, user, account, profile, isNewUser) {
// Since you are using Credentials' provider, the data you're persisting
// _should_ reside in the user here (as far as can I see, since I've just tested it out).
// This gets called whenever a JSON Web Token is created (once) or updated
if (user?.type) {
token.status = user.type
}
if (user?.username) {
token.username = user.username;
}
return token
},
async session(session, token) {
session.type = token.type;
session.username = token.username;
return session
}
}