diff --git a/application.proto b/application.proto
index b5cec9a..eae150d 100644
--- a/application.proto
+++ b/application.proto
@@ -24,6 +24,7 @@ message AppLoadFileRequest {
 
 message AppButtonPressRequest {
     string args = 1;
+    int32 index = 2;
 }
 
 message AppButtonReleaseRequest {