How to get user.$id from received token?

In firebase, from their firebase-admin sdk there is a way to get the user.uid from the token received (sent from front)
obviously for security reasons to make sure users has right to access documents etc from server
=> how to do the same with node-appwrite?

and as a matter of fact, from the front react-native-appwrite, how to get the user token for his current session?

You could create a client using the user session and check if they're authenticated using account.get()

const sessionClient = new Client()
    .setEndpoint('https://cloud.appwrite.io/v1') // Your API Endpoint
    .setProject('<YOUR_PROJECT_ID>');            // Your project ID

const session = req.cookies.session; // Get the session cookie from the request
if (session) {
    sessionClient.setSession(session);
}

(this is from the ssr docs)

this is all frontend though; and only tells me if I'm logged in etc, but I see no token information
the kind of token we usually send inside the headers of a post to backend for security