diff --git a/appmain/callback/Basecallback.java b/appmain/callback/Basecallback.java
new file mode 100644
index 0000000..49c3d89
--- /dev/null
+++ b/appmain/callback/Basecallback.java
@@ -0,0 +1,8 @@
+package com.proxgrind.chameleon.callback;
+
+public interface BaseCallback {
+
+    interface ErrorCallback<T> {
+        void onError(T e);
+    }
+}