diff --git a/tool/api_for_ismm_isat/isat.php b/tool/api_for_ismm_isat/isat.php
index ab0b3d138e..46730ad3ae 100644
--- a/tool/api_for_ismm_isat/isat.php
+++ b/tool/api_for_ismm_isat/isat.php
@@ -6,10 +6,10 @@ header('Cache-Control: private, no-cache, no-store, max-age=0');
 //
 // { Example API for IsAT }
 //
-define('JSON_FILE', './attd.json');
+define('JSON_DIR', 'listdata/');
 //
 //
-if (!file_exists(JSON_FILE))
+if (!file_exists(JSON_DIR) || !file_exists(JSON_DIR . 'antitor_e.json'))
 {
     die('File Not Found');
 }
@@ -19,15 +19,15 @@ elseif ($_SERVER['REQUEST_METHOD'] != 'POST')
     exit;
 }
 header('Content-Type: application/json');
-$got = @json_decode(file_get_contents(JSON_FILE) , true);
-if (!is_array($got))
-{
-    die('File Error');
-}
 $fqdn = htmlspecialchars($_POST['f']);
 if (!preg_match("/^([a-z0-9]{1})([a-z0-9.-]{0,254})\.([a-z]{2,50})$/", $fqdn))
 {
     echo ('[false,false]');
     exit;
 }
+$got = @json_decode(file_get_contents(JSON_DIR . 'antitor_' . $fqdn[0] . '.json') , true);
+if (!is_array($got))
+{
+    die('File Error');
+}
 echo (isset($got[$fqdn]) ? '[true,true]' : '[true,false]');
\ No newline at end of file