RESTlet Run as External API

Hi all,

I've never yet written a RESTlet, so please excuse me if this is a dumb question.  One of my clients wants us to write our own NetSuite API that can be called from their website.  I.e., as a user navigates to a particular page on the client's webpage, it calls a custom-written API that returns to their webpage, some information drawn from their NetSuite account.  This is achievable via a RESTlet right?  I.e., I will be able to run a NetSuite search in my RESTlet and return say, JSON data to the website?

Thanks in advance.