diff --git a/api/fields/message_fields.py b/api/fields/message_fields.py
index e6aebd810f..429e4275d6 100644
--- a/api/fields/message_fields.py
+++ b/api/fields/message_fields.py
@@ -38,6 +38,7 @@ retriever_resource_fields = {
     "index_node_hash": fields.String,
     "content": fields.String,
     "created_at": TimestampField,
+    "doc_metadata": fields.Raw,
 }
 
 message_fields = {