diff --git a/include/webdav_materialize_runtime.inc.php b/include/webdav_materialize_runtime.inc.php
new file mode 100644
index 0000000..31041d1
--- /dev/null
+++ b/include/webdav_materialize_runtime.inc.php
@@ -0,0 +1,274 @@
+<?php
+if (!defined('PHPWG_ROOT_PATH'))
+{
+  die('Hacking attempt!');
+}
+
+function bratonien_tools_webdav_materialize_source_info($image_id)
+{
+  static $cache = array();
+
+  $image_id = (int)$image_id;
+  if ($image_id < 1) return null;
+  if (array_key_exists($image_id, $cache)) return $cache[$image_id];
+
+  $result = pwg_query('SELECT path, coi FROM '.IMAGES_TABLE.' WHERE id='.$image_id.' LIMIT 1');
+  if (!pwg_db_num_rows($result)) return $cache[$image_id] = null;
+
+  $row = pwg_db_fetch_assoc($result);
+  $path = (string)($row['path'] ?? '');
+  if ($path === '') return $cache[$image_id] = null;
+
+  $absolute = $path;
+  if (strpos($absolute, '/') !== 0)
+  {
+    $absolute = PHPWG_ROOT_PATH.ltrim(preg_replace('#^\./#', '', $absolute), '/');
+  }
+
+  $resolved = realpath($absolute);
+  if ($resolved === false) return $cache[$image_id] = null;
+
+  $normalized = str_replace('\\', '/', $resolved);
+  if (!preg_match('#/nc-webdav-source/connection-([0-9]+)/root-([0-9]+)/(.*)$#', $normalized, $match))
+  {
+    return $cache[$image_id] = null;
+  }
+
+  $connection_id = (int)$match[1];
+  $root_fileid = (int)$match[2];
+  $relative_path = trim((string)$match[3], '/');
+  if ($connection_id < 1 || $root_fileid < 1 || $relative_path === '')
+  {
+    return $cache[$image_id] = null;
+  }
+
+  $table = defined('BRATONIEN_TOOLS_NC_CONNECTIONS_TABLE')
+    ? BRATONIEN_TOOLS_NC_CONNECTIONS_TABLE
+    : $GLOBALS['prefixeTable'].'bratonien_tools_nc_connections';
+  $connection_result = pwg_query('SELECT config_json FROM `'.$table.'` WHERE id='.$connection_id.' LIMIT 1');
+  if (!pwg_db_num_rows($connection_result)) return $cache[$image_id] = null;
+
+  $connection_row = pwg_db_fetch_assoc($connection_result);
+  $config = json_decode((string)$connection_row['config_json'], true);
+  if (!is_array($config) || (string)($config['source_mode'] ?? '') !== 'webdav-placeholder')
+  {
+    return $cache[$image_id] = null;
+  }
+
+  $root_found = false;
+  $root_path = '';
+  $roots = isset($config['roots']) && is_array($config['roots']) ? $config['roots'] : array();
+  foreach ($roots as $root)
+  {
+    if ((int)($root['fileid'] ?? 0) === $root_fileid)
+    {
+      $root_found = true;
+      $root_path = trim((string)($root['webdav_path'] ?? ''), '/');
+      break;
+    }
+  }
+  if (!$root_found) return $cache[$image_id] = null;
+
+  $webdav_path = trim($root_path === '' ? $relative_path : $root_path.'/'.$relative_path, '/');
+  if ($webdav_path === '') return $cache[$image_id] = null;
+
+  $content_type = '';
+  $size = 0;
+  $etag = '';
+  $state_dir = rtrim((string)($config['state_dir'] ?? ''), '/');
+  if ($state_dir !== '')
+  {
+    $mapping_file = $state_dir.'/webdav-map.json';
+    if (is_readable($mapping_file))
+    {
+      $mapping = json_decode((string)file_get_contents($mapping_file), true);
+      if (is_array($mapping) && isset($mapping['files']) && is_array($mapping['files']))
+      {
+        $entry = $mapping['files'][$resolved] ?? $mapping['files'][$normalized] ?? null;
+        if (is_array($entry) && (string)($entry['kind'] ?? '') === 'file')
+        {
+          $mapped_path = trim((string)($entry['webdav_path'] ?? ''), '/');
+          if ($mapped_path !== '') $webdav_path = $mapped_path;
+          $content_type = (string)($entry['content_type'] ?? '');
+          $size = (int)($entry['size'] ?? 0);
+          $etag = (string)($entry['etag'] ?? '');
+        }
+      }
+    }
+  }
+
+  return $cache[$image_id] = array(
+    'image_id'=>$image_id,
+    'connection_id'=>$connection_id,
+    'root_fileid'=>$root_fileid,
+    'relative_path'=>$relative_path,
+    'webdav_path'=>$webdav_path,
+    'content_type'=>$content_type,
+    'size'=>$size,
+    'etag'=>$etag,
+    'coi'=>$row['coi'] ?? null,
+  );
+}
+
+function bratonien_tools_webdav_materialize_image_url($image_id)
+{
+  $info = bratonien_tools_webdav_materialize_source_info($image_id);
+  if (!$info) return null;
+
+  $url = get_root_url().'plugins/'.BRATONIEN_TOOLS_ID.'/webdav-image.php?id='.(int)$image_id;
+  if ($info['etag'] !== '') $url .= '&v='.rawurlencode(substr(sha1($info['etag']), 0, 12));
+  return $url;
+}
+
+function bratonien_tools_webdav_materialize_custom_params($key)
+{
+  if (!class_exists('DerivativeParams') || !class_exists('SizingParams')) return null;
+
+  $tokens = explode('_', trim((string)$key));
+  if (!$tokens || $tokens[0] === '') return null;
+
+  $parse_size = function($value)
+  {
+    if (!preg_match('/^[0-9]+(?:x[0-9]+)?$/', (string)$value)) return null;
+    $parts = explode('x', (string)$value, 2);
+    $width = (int)$parts[0];
+    $height = count($parts) === 1 ? $width : (int)$parts[1];
+    if ($width < 1 || $height < 1 || $width > 20000 || $height > 20000) return null;
+    return array($width, $height);
+  };
+
+  $token = array_shift($tokens);
+  $crop = 0;
+  $min_size = null;
+
+  if (isset($token[0]) && $token[0] === 's')
+  {
+    $size = $parse_size(substr($token, 1));
+  }
+  elseif (isset($token[0]) && $token[0] === 'e')
+  {
+    $crop = 1;
+    $size = $min_size = $parse_size(substr($token, 1));
+  }
+  else
+  {
+    if (count($tokens) < 2) return null;
+    $size = $parse_size($token);
+    $crop_token = (string)array_shift($tokens);
+    $min_size = $parse_size(array_shift($tokens));
+    if (!preg_match('/^[a-z]$/', $crop_token) || $min_size === null) return null;
+    $crop = function_exists('char_to_fraction') ? char_to_fraction($crop_token) : 0;
+  }
+
+  if ($size === null) return null;
+
+  $params = new DerivativeParams(new SizingParams($size, $crop, $min_size));
+  if (class_exists('ImageStdParams')) ImageStdParams::apply_global($params);
+  return $params;
+}
+
+function bratonien_tools_webdav_materialize_variant_from_params($params)
+{
+  if (!is_object($params) || !class_exists('ImageStdParams')) return null;
+
+  $type = (string)($params->type ?? '');
+  $defined = ImageStdParams::get_defined_type_map();
+  if ($type !== '' && defined('IMG_CUSTOM') && $type !== IMG_CUSTOM && isset($defined[$type]))
+  {
+    return 'standard:'.$type;
+  }
+
+  if (!method_exists($params, 'add_url_tokens')) return null;
+  $tokens = array();
+  $params->add_url_tokens($tokens);
+  if (!$tokens) return null;
+
+  $key = implode('_', $tokens);
+  if (!preg_match('/^[A-Za-z0-9_x-]+$/', $key)) return null;
+  return 'custom:'.$key;
+}
+
+function bratonien_tools_webdav_materialize_params_from_variant($variant)
+{
+  $variant = trim((string)$variant);
+  if ($variant === '' || !class_exists('ImageStdParams')) return null;
+
+  if (strpos($variant, 'standard:') === 0)
+  {
+    $type = substr($variant, strlen('standard:'));
+    $defined = ImageStdParams::get_defined_type_map();
+    return isset($defined[$type]) ? $defined[$type] : null;
+  }
+
+  if (strpos($variant, 'custom:') === 0)
+  {
+    $key = substr($variant, strlen('custom:'));
+    if (!preg_match('/^[A-Za-z0-9_x-]+$/', $key)) return null;
+    return bratonien_tools_webdav_materialize_custom_params($key);
+  }
+
+  return null;
+}
+
+function bratonien_tools_webdav_materialize_b64url_encode($value)
+{
+  return rtrim(strtr(base64_encode((string)$value), '+/', '-_'), '=');
+}
+
+function bratonien_tools_webdav_materialize_after_signature($image_id, $variant, $after_url)
+{
+  global $conf;
+  $key = !empty($conf['secret_key']) ? $conf['secret_key'] : ($conf['db_password'] ?? 'bratonien-tools');
+  return hash_hmac('sha256', (int)$image_id.'|'.(string)$variant.'|'.(string)$after_url, $key);
+}
+
+function bratonien_tools_webdav_materialize_derivative_url($image_id, $variant, array $info, $after_url='')
+{
+  $url = get_root_url().'plugins/'.BRATONIEN_TOOLS_ID.'/webdav-derivative.php?id='.(int)$image_id.'&variant='.rawurlencode($variant);
+  if ($after_url !== '')
+  {
+    $url .= '&after='.rawurlencode(bratonien_tools_webdav_materialize_b64url_encode($after_url));
+    $url .= '&sig='.rawurlencode(bratonien_tools_webdav_materialize_after_signature($image_id, $variant, $after_url));
+  }
+  if (!empty($info['etag'])) $url .= '&v='.rawurlencode(substr(sha1((string)$info['etag']), 0, 12));
+  return $url;
+}
+
+function bratonien_tools_filter_webdav_materialize_src_url($url, $src_image)
+{
+  if (!is_object($src_image) || empty($src_image->id)) return $url;
+  $webdav_url = bratonien_tools_webdav_materialize_image_url((int)$src_image->id);
+  return $webdav_url ?: $url;
+}
+
+function bratonien_tools_filter_webdav_materialize_derivative_url($url, $params, $src_image, $rel_url)
+{
+  if (!is_object($src_image) || empty($src_image->id)) return $url;
+
+  $image_id = (int)$src_image->id;
+  $info = bratonien_tools_webdav_materialize_source_info($image_id);
+  if (!$info) return $url;
+
+  try
+  {
+    $derivative = new DerivativeImage($params, $src_image);
+    if ($derivative->same_as_source())
+    {
+      $source_url = bratonien_tools_webdav_materialize_image_url($image_id);
+      return $source_url ?: $url;
+    }
+
+    $path = $derivative->get_path();
+    if ($path !== '' && is_file($path) && is_readable($path)) return $url;
+
+    $variant = bratonien_tools_webdav_materialize_variant_from_params($params);
+    if ($variant === null) return $url;
+
+    return bratonien_tools_webdav_materialize_derivative_url($image_id, $variant, $info, (string)$url);
+  }
+  catch (Throwable $e)
+  {
+    error_log('Bratonien WebDAV materialize derivative #'.$image_id.': '.$e->getMessage());
+    return $url;
+  }
+}