Hi all, I wonder is there any way to enforce some relation quantity constraints. For example, A

document:id

resource is defined to allow only one relation

reviewer

with subject

user:id

, If second reviewer is assigned, either simply throws error or overrides the former one.

Hi 👋 you can use

WriteRelationships

with a

Precondition

. For example you can send a request that specifies "no other relationship like this should exist" using operation

OPERATION_MUST_NOT_MATCH

. Please have a look at https://buf.build/authzed/api/docs/main:authzed.api.v1#authzed.api.v1.Precondition