Tool builders have asked for information about the //federation scenario// of a Wikibase instance to be included in WikibaseManifest. Currently there are two such scenarios, both of which can and should be expressed via the concept of //entity sources//:
- the MediaInfo extension as used on Wikimedia Commons, with `wikidata.org` as the entity source for Items, Properties and Lexemes
- the Federated Properties feature with the federation source repo as entity source for Properties
The [Federated Properties documentation](https://doc.wikimedia.org/Wikibase/master/php/md_docs_components_repo-federated-properties.html#autotoc_md98) shows an example of an entity source configuration on a Federated Properties enabled Wikibase. WikibaseManifest could also include RDF prefixes. The `entities` section [in the prototype examples](https://github.com/wmde/WikibaseManifest/blob/master/docs/examples/docker-default.json#L30) may be a good place to include entity source information, and should be renamed to `entity_sources`.
(see T261195 and commments for underlying investigation)