what do you mean by “and matching”?

[:in $ [?match-all-these ...]
 :where
 [?foo :foo/attrs ?match-all-these]]

so that of the collection passed in, the query engine only returns the entities who's attribute contain all of the collection's values

that is, for cardinality/many

No. there’s only one item bound at a time, so it only unifies on one at a time. to bind “all the attr values matching [?foo :foo/attrs]`” to a single thing requires some kind of aggregation.

there are a few approaches to this. The easiest IMO is just to use some clojure code

Other approaches here: https://stackoverflow.com/questions/53875748/filter-by-cardinality-many-field-that-contains-all-the-values

thanks @U09R86PA4 for using the internet which I failed to do 😄

sorry, wrong one

https://stackoverflow.com/questions/43784258/find-entities-whose-ref-to-many-attribute-contains-all-elements-of-input