using woocommerce core without loading themes

Hi
I want to use Woocommerce without loading themes (I want to use Woocommerce library for responding to mobile app requests, so I don’t load the themes), but I can not use it’s functions and classes. I include Woocommerce.php file in my code before using woocomerce functions and classes, but it does not resolve the problem. (For example, when I try to create an object of WC_Order and fetch the order details, it returns nothing).
I think it happens because taxonomy names are registered by loading theme. Is there any way to register Woocommerce taxonomies without loading theme? I want to know where does Woocommerce register it’s taxonomies (in which path/directory/file)?

Thanks