nethsix

Stateless JWT is useful in the scenario where one server is capable of authenticating a user (through password, social login, one-time password, etc.), and a different server holds resources that the user is trying to access.

The server doing the authentication will issue a stateless JWT with all the user credentials cryptographically signed, so that the user can pass the JWT to the server holding the resource to be granted access, assuming that server trusts the authentication server to perform authentication correctly.

Stateless JWT is useful here because the server holding the resources can verify the credentials of the user without contacting the authentication server.

Regarding OAuth, there are 2 sides to it. You can become an OAuth provider, which I reckon you are not interested to be. What you may be interested is to use OAuth to enable users of OAuth providers like Facebook, Twitter, .etc, to access your service, so that you minimize what you have to develop in terms of user management, i.e., you don't have to worry about user creation, email verification, password resets, etc., because all those have been performed by the OAuth providers.

I believe passport.js allows you to use OAuth to allow OAuth providers' users to access your service. passport.js may be a backend-base solution so you have to be somewhat familiar with OAuth to get started.