diff --git a/watermark.php b/watermark.php
new file mode 100644
index 0000000..70331a7
--- /dev/null
+++ b/watermark.php
@@ -0,0 +1,228 @@
+<?php
+define('PHPWG_ROOT_PATH', '../../');
+include_once(PHPWG_ROOT_PATH.'include/common.inc.php');
+
+if (!defined('BRATONIEN_TOOLS_PATH'))
+{
+  http_response_code(500);
+  exit;
+}
+
+require_once(BRATONIEN_TOOLS_PATH.'include/watermark_runtime.inc.php');
+require_once(PHPWG_ROOT_PATH.'admin/include/image.class.php');
+
+function bratonien_tools_runtime_b64url_decode($value)
+{
+  $value = strtr((string)$value, '-_', '+/');
+  $padding = strlen($value) % 4;
+  if ($padding)
+  {
+    $value .= str_repeat('=', 4 - $padding);
+  }
+  return base64_decode($value, true);
+}
+
+function bratonien_tools_watermark_fail($code, $message)
+{
+  http_response_code($code);
+  header('Content-Type: text/plain; charset=utf-8');
+  echo $message;
+  exit;
+}
+
+function bratonien_tools_derivative_physical_path($rel_url)
+{
+  if (strpos($rel_url, "\0") !== false || strpos($rel_url, '..') !== false)
+  {
+    return null;
+  }
+
+  if (strpos($rel_url, PWG_DERIVATIVE_DIR) === 0)
+  {
+    return PHPWG_ROOT_PATH.$rel_url;
+  }
+
+  if (preg_match('#^i(?:\.php)?\?/(.+)$#', $rel_url, $m))
+  {
+    return PHPWG_ROOT_PATH.PWG_DERIVATIVE_DIR.$m[1];
+  }
+
+  if (preg_match('#^i(?:\.php)?/(.+)$#', $rel_url, $m))
+  {
+    return PHPWG_ROOT_PATH.PWG_DERIVATIVE_DIR.$m[1];
+  }
+
+  return null;
+}
+
+function bratonien_tools_fetch_derivative($rel_url, $physical_path)
+{
+  if ($physical_path && is_file($physical_path) && is_readable($physical_path))
+  {
+    return array('path'=>$physical_path, 'temporary'=>false);
+  }
+
+  $url = get_absolute_root_url().ltrim($rel_url, '/');
+  $data = false;
+
+  if (function_exists('curl_init'))
+  {
+    $ch = curl_init($url);
+    curl_setopt_array($ch, array(
+      CURLOPT_RETURNTRANSFER => true,
+      CURLOPT_FOLLOWLOCATION => true,
+      CURLOPT_MAXREDIRS => 3,
+      CURLOPT_CONNECTTIMEOUT => 5,
+      CURLOPT_TIMEOUT => 30,
+      CURLOPT_FAILONERROR => true,
+      CURLOPT_USERAGENT => 'BratonienTools/1.0',
+    ));
+    $data = curl_exec($ch);
+    curl_close($ch);
+  }
+  elseif (ini_get('allow_url_fopen'))
+  {
+    $context = stream_context_create(array('http'=>array('timeout'=>30, 'follow_location'=>1)));
+    $data = @file_get_contents($url, false, $context);
+  }
+
+  if ($data === false || $data === '')
+  {
+    return null;
+  }
+
+  if ($physical_path && is_file($physical_path) && is_readable($physical_path))
+  {
+    return array('path'=>$physical_path, 'temporary'=>false);
+  }
+
+  $ext = 'jpg';
+  if (preg_match('/\.(jpe?g|png|gif|webp)(?:$|\?)/i', $rel_url, $m))
+  {
+    $ext = strtolower($m[1]);
+  }
+  $tmp = tempnam(sys_get_temp_dir(), 'btwm_');
+  $tmp_with_ext = $tmp.'.'.$ext;
+  @rename($tmp, $tmp_with_ext);
+  file_put_contents($tmp_with_ext, $data);
+
+  return array('path'=>$tmp_with_ext, 'temporary'=>true);
+}
+
+function bratonien_tools_output_image($path)
+{
+  $ext = strtolower(pathinfo($path, PATHINFO_EXTENSION));
+  $types = array(
+    'jpg'=>'image/jpeg', 'jpeg'=>'image/jpeg', 'png'=>'image/png',
+    'gif'=>'image/gif', 'webp'=>'image/webp',
+  );
+  header('Content-Type: '.($types[$ext] ?? 'application/octet-stream'));
+  header('Content-Length: '.filesize($path));
+  header('Cache-Control: public, max-age=604800');
+  readfile($path);
+  exit;
+}
+
+if (!bratonien_tools_watermark_engine_enabled())
+{
+  bratonien_tools_watermark_fail(404, 'Watermark engine disabled');
+}
+
+$profile_id = (int)($_GET['p'] ?? 0);
+$encoded_url = (string)($_GET['u'] ?? '');
+$signature = (string)($_GET['s'] ?? '');
+$rel_url = bratonien_tools_runtime_b64url_decode($encoded_url);
+
+if ($profile_id <= 0 || $rel_url === false || $rel_url === '')
+{
+  bratonien_tools_watermark_fail(400, 'Invalid request');
+}
+
+$expected = bratonien_tools_runtime_sign($rel_url, $profile_id);
+if (!hash_equals($expected, $signature))
+{
+  bratonien_tools_watermark_fail(403, 'Invalid signature');
+}
+
+$profile = bratonien_tools_get_watermark_profile($profile_id);
+if (!$profile || empty($profile['watermark_file']))
+{
+  bratonien_tools_watermark_fail(404, 'Watermark profile unavailable');
+}
+
+$watermark_root = realpath(PHPWG_ROOT_PATH.PWG_LOCAL_DIR.'watermarks');
+$watermark_path = realpath(PHPWG_ROOT_PATH.PWG_LOCAL_DIR.'watermarks/'.$profile['watermark_file']);
+if (!$watermark_root || !$watermark_path || strpos($watermark_path, $watermark_root.DIRECTORY_SEPARATOR) !== 0 || !is_file($watermark_path))
+{
+  bratonien_tools_watermark_fail(404, 'Watermark file unavailable');
+}
+
+$physical_path = bratonien_tools_derivative_physical_path($rel_url);
+$source = bratonien_tools_fetch_derivative($rel_url, $physical_path);
+if (!$source)
+{
+  bratonien_tools_watermark_fail(502, 'Derivative could not be generated');
+}
+
+$ext = strtolower(pathinfo($source['path'], PATHINFO_EXTENSION));
+if (!in_array($ext, array('jpg','jpeg','png','gif','webp'), true))
+{
+  $ext = 'jpg';
+}
+
+$cache_dir = PHPWG_ROOT_PATH.PWG_DERIVATIVE_DIR.'bratonien-watermark/'.$profile_id;
+if (!is_dir($cache_dir) && !mkdir($cache_dir, 0755, true) && !is_dir($cache_dir))
+{
+  if ($source['temporary']) @unlink($source['path']);
+  bratonien_tools_watermark_fail(500, 'Cache directory unavailable');
+}
+
+$cache_fingerprint = array(
+  $rel_url,
+  $profile['watermark_file'], $profile['xpos'], $profile['ypos'], $profile['opacity'],
+  $profile['min_width'], $profile['min_height'], @filemtime($watermark_path),
+);
+$cache_path = $cache_dir.'/'.sha1(implode('|', $cache_fingerprint)).'.'.$ext;
+
+if (is_file($cache_path))
+{
+  if ($source['temporary']) @unlink($source['path']);
+  bratonien_tools_output_image($cache_path);
+}
+
+$image = new pwg_image($source['path']);
+$width = $image->get_width();
+$height = $image->get_height();
+
+if ($width < (int)$profile['min_width'] || $height < (int)$profile['min_height'])
+{
+  $image->destroy();
+  bratonien_tools_output_image($source['path']);
+}
+
+$wm = new pwg_image($watermark_path);
+$wm_width = $wm->get_width();
+$wm_height = $wm->get_height();
+
+if ($width < $wm_width || $height < $wm_height)
+{
+  $scale = min($width / $wm_width, $height / $wm_height);
+  $wm_width = max(1, (int)floor($wm_width * $scale));
+  $wm_height = max(1, (int)floor($wm_height * $scale));
+  $wm->resize($wm_width, $wm_height);
+}
+
+$x = (int)round(((int)$profile['xpos'] / 100) * ($width - $wm_width));
+$y = (int)round(((int)$profile['ypos'] / 100) * ($height - $wm_height));
+$image->compose($wm, $x, $y, (int)$profile['opacity']);
+$wm->destroy();
+$image->write($cache_path);
+$image->destroy();
+@chmod($cache_path, 0644);
+
+if ($source['temporary'])
+{
+  @unlink($source['path']);
+}
+
+bratonien_tools_output_image($cache_path);