diff --git a/cps-ncmp-rest/docs/openapi/components.yaml b/cps-ncmp-rest/docs/openapi/components.yaml
index d82813b..4dd7e47 100644
--- a/cps-ncmp-rest/docs/openapi/components.yaml
+++ b/cps-ncmp-rest/docs/openapi/components.yaml
@@ -329,6 +329,18 @@
         sample 3:
           value:
             options: (depth=2,fields=book/authors)
+    topicParamInQuery:
+      name: topic
+      in: query
+      description: topic parameter in query.
+      required: false
+      schema:
+        type: string
+      allowReserved: true
+      examples:
+        sample 1:
+          value:
+            topic: my-topic-name
     contentParamInHeader:
       name: Content-Type
       in: header