diff --git a/query/snapshot/src/main/java/me/hsgamer/topper/query/snapshot/SnapshotQuery.java b/query/snapshot/src/main/java/me/hsgamer/topper/query/snapshot/SnapshotQuery.java
index 104eedb..4c586d4 100644
--- a/query/snapshot/src/main/java/me/hsgamer/topper/query/snapshot/SnapshotQuery.java
+++ b/query/snapshot/src/main/java/me/hsgamer/topper/query/snapshot/SnapshotQuery.java
@@ -61,6 +61,8 @@ protected SnapshotQuery() {
                         .map(index -> index + 1)
                         .map(Object::toString)
                         .orElse("0"));
+        registerAction("top_size", (actor, context) ->
+                Integer.toString(context.agent.getSnapshot().size()));
     }
 
     protected abstract Optional<SnapshotAgent<K, V>> getAgent(@NotNull String name);