diff --git a/protobuf/flagd/evaluation/v1/evaluation.proto b/protobuf/flagd/evaluation/v1/evaluation.proto
index 724c209..a142419 100644
--- a/protobuf/flagd/evaluation/v1/evaluation.proto
+++ b/protobuf/flagd/evaluation/v1/evaluation.proto
@@ -44,6 +44,9 @@ message AnyFlag {
     double double_value = 5;
     google.protobuf.Struct object_value = 6;
   }
+
+  // Metadata about this flag, see https://openfeature.dev/specification/types/#flag-metadata
+  google.protobuf.Struct metadata = 7;
 }
 
 // Request body for boolean flag evaluation, used by the ResolveBoolean rpc.