diff --git a/src/Api/IApi.php b/src/Api/IApi.php
index 4227279..00368cf 100644
--- a/src/Api/IApi.php
+++ b/src/Api/IApi.php
@@ -38,6 +38,12 @@ public function getInputElements(): array;
      */
     public function getOutputElements(): array;
 
+    /**
+     * Get all direction changing elements of the remote function.
+     * @return IApiElement[]
+     */
+    public function getChangingElements(): array;
+
     /**
      * Get all tables of the remote function.
      * @return IApiElement[]