Script before authentification

Is it possible to create a module that run before the user authentification on the client or on the designer?

Thanks,

I would suggest instead that you auto login to your project using a basic default user that only has access to one window, which would be a custom login screen that you build. This way, you can run a script right after the auto login happens and you can then have your user login in your custom login window. What kind of a script were you trying to run?