Depends what you will use for auth server side. You either implement google/apple/facebook/… sign in, and call it a day. Or you also implement your own app’s auth (if you want iOS, you need at least apple sign in on top), and there you need an identity backend server, often times with its login/register pages. Anyway, react native wise, all you gotta do is follow the docs of expo authentication. You use expo-auth-session. Look at expo documentation, tell us what you want to implement for signing/logging. It should cover most sane cases of authentication. Sometimes you should use specific vendor auth (like Google or Facebook) that is basically a small wrapper around expo-auth-session, because it’s not sane to do otherwise. Idk exactly what you know about the topic of authentication, but it’s a solved problem, and if you were to rewrite everything from scratch, you will end up pouring tons of hours in a bugged insecure implementation. It is not that complicated to make a form sending a login and a password to a server that sends you back a token to send in headers. But the complex protocols used in the current solutions have reasons, and even if you work fullstack and write the strict minimum for a POC not to use in production, the job would take way too long. If you are familiar with the authentication topic, then feel free to implement oAuth2.0, PCKE, … it’s not that complicated, because all you gotta do is follow the protocol. But at that point you will know it’s okay to use expo-auth-session and/or vendor wrappers. Answer from Merry-Lane on reddit.com