Hey, i love ln-url and i've written a starter project for everyone interested in playing around with it. Here is the auth part if you want to see an actual implementation: https://github.com/zerealschlauskwab/lnapp-starter/blob/master/src/server/routers/auth.ts

The only thing that still bugs me a bit about the auth part is the fact that if your web app depends on ln-url auth only, all your account data is dependent on ICANN eg. a centralised institution. It would be nice if the wallets could receive an array of authentication urls instead of one:

[
   "https://www.mylnapp.com/authenticate",
   "https://www.backuplnauthprovider.com/mylnapp/authenticate"
] 

...so that you can backup you users public keys if something goes wrong. Any thoughts on that?