Users of the Wikibase API who need to format many entity IDs (e. g. in QuickStatements, Wikidata Graph Builder, Wikidata Recent Changes, or Wikidata Reconciliation) can now use a new API module for this: wbformatentities. It combines advantages of wbgetentities and wbformatvalue: as in wbformatvalue, you can use Wikibase’ own logic for formatting entities (so you don’t have to worry about downloading labels, applying language fallbacks, dealing with other entity types like lexemes, etc.), but as in wbgetentities, you can process large numbers of entities at once, instead of making one API call per entity.
The module is currently kept very simple: you specify a list of entity IDs with the ids parameter, and the API returns a list of HTML snippets corresponding to those IDs. (Support for other output formats may be added later; let us know if it would be useful to you.) The language can be controlled via the global uselang parameter. Normal users can format up to 50 entities at once, bots up to 500.
Please let us know if you have any comments, either by responding here or over on Phabricator at T207484 https://phabricator.wikimedia.org/T207484.
-- Lucas