diff --git a/cgi-bin/vorbereitung/api.php b/cgi-bin/vorbereitung/api.php
new file mode 100644
index 0000000..d8a6e99
--- /dev/null
+++ b/cgi-bin/vorbereitung/api.php
@@ -0,0 +1,13 @@
+<?php
+
+$n = $_REQUEST['n'];
+
+header("Content-Type: application/json");
+
+echo(lenschomode($n));
+
+function lenschomode($n) {
+        return pow($n,2);
+}
+
+?>