Hello! This is a breaking change announcement regarding the WikibaseClient wblistentityusage API module. This API module is used for listing all pages that make use of data from a given entity via Lua, parser functions, or Sitelinks.

Currently, this API module has two issues:

• When using this module as a value for the list parameter in an API query action, the results are added to the query.pages key in the response object. However, this key is reserved for use with the following parameters: generator, titles, pageids, and revids. This could lead to a collision if used alongside one of these parameters, potentially causing a runtime exception.

• The API parameter prefix wbeu is shared between list=wblistentityusage and prop=wbentityusage (a different module that instead lists all entities used on a given page). However, the module prefix must be globally unique.

We are addressing both issues at the time. Starting today, you can use the wblistentityusage API with the parameter prefix wbleu instead of wbeu, and the results will be added under query.entityusage instead of query.pages. However, the old prefix (wbeu) is still supported for some time, and will continue to produce the same output as before (with an additional deprecation warning).

On or shortly after 2023-05-17, we will remove support for the old prefix and output format from the API. Thus, you now have two weeks to migrate to the new prefix and output format. For a comparison between the old and new methods of using the API, please refer to the wbeu version and wbleu version examples.

If you have any questions or concerns about this change, please don’t hesitate to reach out to us via tickets T196962 or T300460.

Cheers,