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

SuperTokens.com

Ah ok. Unfortunately, we don't support that at the moment. However, you could use us for auth in `auth.example.com`, and then use some other solution like ORY Hydra to make `auth.example.com` into an OAuth provider and connect that with `someotherdomain.com`, and then, in `someotherdomain.com`, you could use us for sessions as well.