I guess it depends on what you mean by "user account", but you need some way to authenticate the fact that an incoming request has been paid for. Maybe that's v

I guess it depends on what you mean by "user account", but you need some way to authenticate the fact that an incoming request has been paid for. Maybe that's via a traditional auth method like a user account, maybe that's a client key whose accesses are kept track of server-side, maybe it's something stupid like bundling every request to your service with a cryptocurrency payment on the blockchain that your service watches for, and then responds to.