This is a pretty good analysis of the situation I think. The only thing that I would like to point out is that only a description of the API is available via th

This is a pretty good analysis of the situation I think. The only thing that I would like to point out is that only a description of the API is available via the Zanzibar paper. We, and other clean-room implementations, have had to fill in the gaps around what the APIs actually look like. We've even made some of our own improvements such as resource lookup by subject[0] and a filter-based delete that mirrors the read API[1]. [0] https://authzed.com/blog/acl-filtering-in-authzed/ https://authzed.com/blog/acl-filtering-in-authzed/ [1] https://buf.build/authzed/api/docs/main/authzed.api.v1#authzed.api.v1.DeleteRelationshipsRequest https://buf.build/authzed/api/docs/main/authzed.api.v1#authz...