Several Rest services have been implemented in GeneXus Server, which make it possible to obtain information about the KBs being hosted, its objects and properties.
These services, in addition to allowing users to query the KBs stored in GXserver, can be used to view and compare an object of the local KB with that one of GXserver. It may be even possible to bring just an object to the local KB.
These services can be consumed from different clients, including GeneXus applications (using the httpclient data type).
For a detailed description on the available services check the SAC # 29353.
If you want to extend the API provided, check this article.