MODX class as php framework

Hi,

Is it possible to use the MODX class as php framework; instead of using something like codeigniter I'd like to do it with MODX.
I mostly need the database part for now. The project will probably use twitter's bootstrap, be kind of ajax oriented and hopefully I can use/learn PDO as well

Because I don't have control over the server I'd like to first test MODX class so the questions are
- what files do I need to download/upload on the server?
- what config files do I need to configure to test the connection to the DB?

Thanks