Implementing programatic access to a database using dblink?

Hi,

Our database (8.2.6) runs on a separate machine from the web
interface. Each user has their own username/password and row level
security is handled by a set of views on top of the base tables.

I'd like to provide programatic access to my database (I have been
looking at Perl's DBIx::Class), but I want to control which tables/
views can be queried via this route. I thought of creating a second
database with views wrapping dblink queries to the main database. The
problem is that the dblink query needs to send a password even after
the user has been authenticated against the first. Is there a way to
get this to work or to get around this?

Maybe on a more general note i wonder if those with more experience
than me knows, does this approach sound like complete madness or are
there better ways to approach this?

thanks for any help

Adam