diff --git a/.gitignore b/.gitignore
index ce2c1b4..3081f8d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 /hook/gogs_key.php
 /hook/logs.txt
 /hook/list.json
+/hook/HashKey.php
diff --git a/hook/HashKey.orig.php b/hook/HashKey.orig.php
new file mode 100644
index 0000000..8aadd66
--- /dev/null
+++ b/hook/HashKey.orig.php
@@ -0,0 +1,7 @@
+<?php
+
+namespace sammo\img_service;
+
+class HashKey{
+    const KEY = '=HashKey=';
+}
\ No newline at end of file
diff --git a/hook/git_pull.php b/hook/git_pull.php
new file mode 100644
index 0000000..123f877
--- /dev/null
+++ b/hook/git_pull.php
@@ -0,0 +1,76 @@
+<?php
+namespace sammo\img_service;
+
+include(__DIR__.'/gogs_key.php');
+
+header('Content-Type: application/json');
+
+function hashPassword($salt, $password)
+{
+    return hash('sha512', $salt.$password.$salt);
+}
+
+$req_hash = $_REQUEST['req']??'';
+$req_time = $_REQUEST['time']??0;
+
+$json_response = [
+    'result'=>false,
+    'reason'=>'Unknown'
+];
+
+if(!$req_hash){
+    $json_response['reason'] = 'no req';
+    die(json_encode($json_response));
+}
+if(!$req_time || !is_numeric($req_time)){
+    $json_response['reason'] = 'invalid time';
+    die(json_encode($json_response));
+}
+
+$key = HashKey::KEY;
+if(strlen($key)<16){
+    $json_response['reason'] = 'key is too short';
+    die(json_encode($json_response));
+}
+
+$timestamp = time();
+
+if(abs($timestamp - $req_time) > 300){
+    $json_response['reason'] = 'time difference';
+    die(json_encode($json_response));
+}
+
+$ans_hash = hashPassword(sprintf("%016x", $req_time), $key);
+
+if($ans_hash != $req_hash){
+    $json_response['reason'] = 'hash mismatch';
+    die(json_encode($json_response));
+}
+
+exec("git pull -q 2>&1", $output);
+
+exec("git ls-files -z ../icons", $raw_img_list);
+$raw_img_list = explode("\x00", $raw_img_list[0]);
+$img_list = [];
+
+foreach ($raw_img_list as $path) {
+    $pos = strpos($path, '../icons/');
+    if($pos === false){
+        continue;
+    }
+    $path = substr($path, $pos + 9);
+
+
+    $pathinfo = pathinfo($path);
+    $dpath = $pathinfo['dirname'];
+    $basename = $pathinfo['basename'];
+    $filename = $pathinfo['filename'];
+
+    if(!\key_exists($dpath, $img_list)){
+        $img_list[$dpath] = [];
+    }
+    $img_list[$dpath][$filename] = $basename;
+
+}
+
+file_put_contents('list.json', json_encode($img_list));