diff --git a/include/public_selection.inc.php b/include/public_selection.inc.php
new file mode 100644
index 0000000..583e8c9
--- /dev/null
+++ b/include/public_selection.inc.php
@@ -0,0 +1,110 @@
+<?php
+if (!defined('PHPWG_ROOT_PATH'))
+{
+  die('Hacking attempt!');
+}
+
+/**
+ * Adds a public multi-photo selection mode to album thumbnail pages.
+ * The actual ZIP generation remains handled by Batch Downloader.
+ */
+function bratonien_tools_public_selection_init()
+{
+  if (defined('IN_ADMIN'))
+  {
+    return;
+  }
+
+  add_event_handler('loc_end_index', 'bratonien_tools_public_selection_render', EVENT_HANDLER_PRIORITY_NEUTRAL + 30);
+  add_event_handler('batchdownload_get_set_info', 'bratonien_tools_public_selection_filter_set', EVENT_HANDLER_PRIORITY_NEUTRAL + 30, 1);
+}
+
+function bratonien_tools_public_selection_render()
+{
+  global $page, $template;
+
+  if (!defined('BATCH_DOWNLOAD_PATH') || !function_exists('check_download_access'))
+  {
+    return;
+  }
+
+  if (check_download_access() === false)
+  {
+    return;
+  }
+
+  if (empty($page['items']) || empty($page['section']) || $page['section'] !== 'categories' || empty($page['category']))
+  {
+    return;
+  }
+
+  $template->assign(array(
+    'BRATONIEN_SELECTION_PATH' => 'plugins/'.BRATONIEN_TOOLS_ID,
+    'BRATONIEN_SELECTION_DOWNLOAD_URL' => bratonien_tools_public_selection_download_url(),
+  ));
+
+  $template->set_filename('bratonien_selection_assets', BRATONIEN_TOOLS_PATH.'template/public_selection_assets.tpl');
+  $template->parse('bratonien_selection_assets', false);
+
+  $button = '<a href="#" id="bratonien-selection-toggle" class="pwg-icon" title="Bilder auswaehlen">'
+    .'<span class="fas fa-check-square" aria-hidden="true"></span>'
+    .'<span class="bratonien-selection-toolbar-label">Auswahl</span>'
+    .'</a>';
+
+  $template->add_index_button($button, 49);
+}
+
+function bratonien_tools_public_selection_download_url()
+{
+  $url = duplicate_index_url(array(), array('action', 'down_size', 'bratonien_selection'));
+  return add_url_params($url, array('action' => 'advdown_set'));
+}
+
+/**
+ * Restricts the Batch Downloader set to the image IDs selected in the public UI.
+ * The intersection with the current Piwigo set prevents downloading images that
+ * are not part of the currently accessible album/result set.
+ */
+function bratonien_tools_public_selection_filter_set($set)
+{
+  if (!is_array($set))
+  {
+    return $set;
+  }
+
+  if (empty($_GET['action']) || $_GET['action'] !== 'advdown_set' || !isset($_GET['bratonien_selection']))
+  {
+    return $set;
+  }
+
+  $raw = is_array($_GET['bratonien_selection'])
+    ? implode(',', $_GET['bratonien_selection'])
+    : (string)$_GET['bratonien_selection'];
+
+  $selected = array_values(array_unique(array_filter(array_map('intval', preg_split('/[^0-9]+/', $raw)))));
+  if (empty($selected))
+  {
+    $set['items'] = array();
+    return $set;
+  }
+
+  $allowed = array_map('intval', isset($set['items']) && is_array($set['items']) ? $set['items'] : array());
+  $allowed_lookup = array_fill_keys($allowed, true);
+
+  $filtered = array();
+  foreach ($selected as $image_id)
+  {
+    if (isset($allowed_lookup[$image_id]))
+    {
+      $filtered[] = $image_id;
+    }
+  }
+
+  $set['items'] = $filtered;
+  $set['type'] = 'bratonien_selection';
+  $set['id'] = isset($set['id']) ? $set['id'] : null;
+
+  return $set;
+}
+
+bratonien_tools_public_selection_init();