diff --git a/appmain/callback/actioncallback.java b/appmain/callback/actioncallback.java
new file mode 100644
index 0000000..f3db4f8
--- /dev/null
+++ b/appmain/callback/actioncallback.java
@@ -0,0 +1,7 @@
+package com.proxgrind.chameleon.callback;
+
+public interface ActionCallback<S, F> {
+    void onSuccess(S s);
+
+    void onFail(F f);
+}