One of the initial limitations of the API was that it only could be used to add items to your "staging" site - but actually getting those items on the live site still required a full site publish. With a recently launched update, this no longer is the case!
The default behavior is staying the same, that is items will only be added to your staging site - but with the update it now is possible to specify that you want your item to also be included in your live site. There are a couple of caveats with this - but the API docs have the full details.
Let me know if you run into any issues with this and I'll be happy to look into them for you!