Wikidata query service/Usage
This page lists uses of Wikidata Query Service inside Wikimedia Foundation projects. Any change to the service should account for these services' existence and requirements.
Example: Goat locator service
This is the example service description, intended to show how you could describe your usage of WDQS. Please note this is not a real service and the description is only meant to illustrate the suggested format.
Service goal: display a list of notable goats within 10 miles of location of the current item
Service type: interactive, runs each time user loads a page which has coordinates
Distinguishing mark: the queries will have "#Goat Locator" in the query text
Expected traffic: about 10 queries per minute, each query is a geosearch which typically takes about 700 ms.
Maintained by: Smalyshev
WikibaseQualityConstraints (which powers the checkConstraints gadget and d:Special:ConstraintReport) uses WDQS for the “type”, “value type”, “distinct values” and “format” constraint types. The templates for all queries can be found in SparqlHelper.php (look for
$query =, or
Service goal: Check consistency of data in Wikidata entities
Service type: Interactive, runs every time a user with the checkConstraints gadget enabled loads an entity page, or any user uses d:Special:ConstraintReport (which is rare).
Distinguishing mark: All queries begin with a comment line
Expected traffic: Some 100 queries per minute (but fluctuating a lot, and will increase as more users enable the gadget; see also grafana), with a
maxQueryTimeMillis of 5000 (see
$wgWBQualityConstraintsSparqlMaxMillis in Wikibase-production config)
Maintained by: Lucas Werkmeister
Gadgets and user scripts
Service goal: allow users to easily search for Wikidata entities with missing labels in Wikidata, but with local label in Wikipedia infoboxes.
Service type: interactive, runs each time user press a sidebar button in template
Distinguishing mark: all queries will have similar structure to queryMissingLabels() function
Expected traffic: user driven
Source code: HarvestLabel
Service goal: allow a user browsing a Commons category to see if a Wikidata item points there using P373
Service type: user script. Activated whenever a user with the script enabled loads a Commons category page.
Distinguishing mark: all queries will have a very similar structure -- see source below
Expected traffic: user driven (but I think uptake has been quite limited, in the 2 1/2 years that it's existed for so far)
Source code: c:User:Jheald/wdcat.js