The Wikibase extension ( that runs http://www.wikidata.org ) has an Api Module to merge two items (called MergeItems) .

The only way to use this function currently is to use the API directly. A Special Page should be created with the same functionality as the api module so that people can use it through the site itself.

See this bug report for more information / queries.

Students are required to read Wikimedia's general Instructions first. Patches should be submitted to Gerrit and reference the bug report in the commit message.