How to hide url after domain in web2py?
Well I guess you're going to have a build the worlds most remarkable single page application :) Security through obscurity is never a good design pattern.
There is absolutely no security "reason" for hiding a URL if your system is designed in a such a way that the use of the URLs is meaningless unless the access control layer defines permissions for such use (usually through an authentication and role/object based permission architecture).
Keep in mind - anyone these days can use Chrome inspector to see whatever you are trying to hide in the address bar.
For example. Say you want to load domain.com/adduser 
Sure you make an AJAX call to that URL, and the browser address bar would never change from domain.com/ - but a quick look in the source will uncover /adduser pretty quickly.
Sounds like you need to have a think about what these addresses really expose and start locking them down.
I am building a website using web2py. For security reasons I would like to hide the url after the domain to the visitors. For example, when a person clicks a link to "domain.com/abc", it will go to that page and the address bar shows "domain.com".
I have played with the routes_in and routes_out, but it only seems to map your typed url to a destination but not hiding the url.
How can I do that? Thanks!