diff --git a/authzed/api/v1/permission_service.proto b/authzed/api/v1/permission_service.proto
index 92be334..a08ac29 100644
--- a/authzed/api/v1/permission_service.proto
+++ b/authzed/api/v1/permission_service.proto
@@ -190,6 +190,12 @@ message RelationshipFilter {
     max_bytes : 1024,
   } ];
 
+  // optional_resource_ids is the *optional* list of resource IDs to filter relationships.
+  // If specified, optional_resource_id and optional_resource_id_prefix cannot be specified.
+  repeated string optional_resource_ids = 6 [ (validate.rules).repeated .string = {
+    pattern : "^([a-zA-Z0-9/_|\\-=+]{1,})?$",
+    max_bytes : 1024,
+  } ];
 
   // relation is the *optional* relation of the relationship.
   string optional_relation = 3 [ (validate.rules).string = {
@@ -223,6 +229,13 @@ message SubjectFilter {
     max_bytes : 1024,
   } ];
 
+  // optional_subject_ids is the *optional* list of subject IDs to filter.
+  // If specified, optional_subject_id cannot be specified.
+  repeated string optional_subject_ids = 4 [ (validate.rules).string = {
+    pattern : "^(([a-zA-Z0-9/_|\\-=+]{1,})|\\*)?$",
+    max_bytes : 1024,
+  } ];
+
   RelationFilter optional_relation = 3;
 }
 
@@ -257,6 +270,10 @@ message ReadRelationshipsResponse {
   // relationship is the found relationship.
   Relationship relationship = 2 [ (validate.rules).message.required = true ];
 
+  // optional_relationships are a list of relationships found when multiple resource and subject ids are
+  // specified in the request
+  repeated Relationship optional_relationships = 3 [ (validate.rules).message.required = true ];
+
   // after_result_cursor holds a cursor that can be used to resume the ReadRelationships stream after this
   // result.
   Cursor after_result_cursor = 3;