From Meta, a Wikimedia project coordination wiki
The Wikidata API will simply be an extension of the existing MediaWiki API.
|The API is documented on mw:Extension:Wikibase/API and in
searchByName(language, fragment, *hints)
- This is used in the Wikidata Suggest widget, but a good text search facility isn't available for the moment.
- This is a continuous work in progress, and the current version will probably not be the final solution.
Wikibase Client 
changeSiteLinks( ( id XOR title ), changes )
- Gets called by the site links UI of the local wiki and contains a list of additions and removals which should be propagated to the repo. This is thus a proxy API module. Should look into immediately updating the local link list to not have to wait for the repo to run the job that will push the change back. In fact, we might want the repo to skip updating this client wiki altogether.