SuperTokens is an open source authentication solution offering features like: Different types of login: Email / password, Passwordless (OTP or Magic link based).

SuperTokens.com

I'm currently using Hasura and Magic Link to basically authenticate users and save their issuer and information with sessions in the server as a cookie session JWT.

How easy would it be to migrate to supertokens?

We have migration docs for magic links + guides to integrate with hasura + using cookies based sessions + creating a JWT. Seems like exactly what you need

my goal is to be able to rewrite as little of my backend session management code as possible

I'll check out the migration later tonight

Oh I see. If you want to use our session management, you will have to remove your backend seesion managent code and use ours instead.

But you can also use us without session management (and just for magic links) and continue to use your sessions management

So I can't use my own backend session manager?

My backend is written in fastify using `fastify-session` , `jsonwebtoken`, and remix frameworks' built in session manager