diff --git a/include/nc_productive_ws.inc.php b/include/nc_productive_ws.inc.php
index cf6d763..f63e1d0 100644
--- a/include/nc_productive_ws.inc.php
+++ b/include/nc_productive_ws.inc.php
@@ -18,7 +18,7 @@ function bratonien_tools_register_nc_productive_ws_methods($arr)
         'info' => 'Piwigo storage site to synchronize. Default: 1.',
       ),
     ),
-    'Runs the approved Piwigo filesystem synchronization for the Bratonien NC Connector.',
+    'Runs the approved direct Bratonien filesystem synchronization for the NC Connector.',
     null,
     array(
       'admin_only' => true,
@@ -27,9 +27,17 @@ function bratonien_tools_register_nc_productive_ws_methods($arr)
   );
 }
 
+function bratonien_tools_nc_productive_error(&$errors, $path, $type)
+{
+  $errors[] = array(
+    'path' => (string)$path,
+    'type' => (string)$type,
+  );
+}
+
 function bratonien_tools_ws_nc_sync_productive($params, &$service)
 {
-  global $conf, $user, $template, $page;
+  global $conf, $user;
 
   $piwigo_version = defined('PHPWG_VERSION') ? (string)PHPWG_VERSION : '';
   if ($piwigo_version !== '16.4.0')
@@ -51,95 +59,379 @@ function bratonien_tools_ws_nc_sync_productive($params, &$service)
     return new PwgError(400, 'Invalid site_id.');
   }
 
-  $saved_get = $_GET;
-  $saved_post = $_POST;
-  $saved_request_method = isset($_SERVER['REQUEST_METHOD']) ? $_SERVER['REQUEST_METHOD'] : null;
-  $saved_default_status = isset($conf['newcat_default_status']) ? $conf['newcat_default_status'] : null;
-  $saved_template_dirs = null;
-  $output = '';
-  $counts = array();
+  include_once(PHPWG_ROOT_PATH.'admin/include/functions.php');
+  include_once(PHPWG_ROOT_PATH.'admin/site_reader_local.php');
+
+  $query = '\nSELECT galleries_url\n  FROM '.SITES_TABLE.'\n  WHERE id = '.$site_id.'\n  LIMIT 1';
+  $result = pwg_query($query);
+  if (!pwg_db_num_rows($result))
+  {
+    return new PwgError(404, 'Piwigo site does not exist.');
+  }
+
+  list($site_url) = pwg_db_fetch_row($result);
+  if (url_is_remote($site_url))
+  {
+    return new PwgError(400, 'Remote Piwigo sites are not supported by this synchronization method.');
+  }
+
+  $site_reader = new LocalSiteReader($site_url);
+  if (!$site_reader->open())
+  {
+    return new PwgError(500, 'Piwigo could not open the configured local site.');
+  }
+
+  list($dbnow) = pwg_db_fetch_row(pwg_query('SELECT NOW()'));
+  $errors = array();
+  $counts = array(
+    'new_categories' => 0,
+    'del_categories' => 0,
+    'new_elements' => 0,
+    'del_elements' => 0,
+    'upd_elements' => 0,
+    'new_formats' => 0,
+    'del_formats' => 0,
+    'metadata_candidates' => 0,
+    'metadata_updated' => 0,
+  );
 
   try
   {
-    if (!defined('IN_ADMIN'))
+    // -----------------------------------------------------------------
+    // Directories / physical categories. Connector imports are private.
+    // -----------------------------------------------------------------
+    $query = '\nSELECT id, id_uppercat, uppercats, global_rank, status, visible\n  FROM '.CATEGORIES_TABLE.'\n  WHERE dir IS NOT NULL\n    AND site_id = '.$site_id;
+    $db_categories = hash_from_query($query, 'id');
+    $db_fulldirs = get_fulldirs(array_keys($db_categories));
+    $basedir = preg_replace('#/*$#', '', $site_url);
+    $db_fulldirs = array_flip($db_fulldirs);
+    $fs_fulldirs = $site_reader->get_full_directories($basedir);
+
+    $next_rank = array('NULL'=>1);
+    $result = pwg_query('SELECT id FROM '.CATEGORIES_TABLE);
+    while ($row = pwg_db_fetch_assoc($result))
     {
-      define('IN_ADMIN', true);
+      $next_rank[$row['id']] = 1;
+    }
+    $result = pwg_query('SELECT id_uppercat, MAX(`rank`)+1 AS next_rank FROM '.CATEGORIES_TABLE.' GROUP BY id_uppercat');
+    while ($row = pwg_db_fetch_assoc($result))
+    {
+      $key = empty($row['id_uppercat']) ? 'NULL' : $row['id_uppercat'];
+      $next_rank[$key] = (int)$row['next_rank'];
     }
 
-    // ws.php uses the gallery template context. Piwigo's admin/site_update.php
-    // also initializes the admin tabsheet and therefore needs the admin
-    // template directory (tabsheet.tpl, site_update.tpl, ...).
-    if (is_object($template) && isset($template->smarty) && method_exists($template, 'set_template_dir'))
+    $next_id = pwg_db_nextval('id', CATEGORIES_TABLE);
+    $category_inserts = array();
+
+    foreach (array_diff($fs_fulldirs, array_keys($db_fulldirs)) as $fulldir)
     {
-      $saved_template_dirs = $template->smarty->getTemplateDir();
-      $template->set_template_dir(PHPWG_ROOT_PATH.'admin/themes/default/template');
+      $dir = basename($fulldir);
+      if (!preg_match($conf['sync_chars_regex'], $dir))
+      {
+        bratonien_tools_nc_productive_error($errors, $fulldir, 'PWG-UPDATE-1');
+        continue;
+      }
+
+      $insert = array(
+        'id' => $next_id++,
+        'dir' => $dir,
+        'name' => str_replace('_', ' ', $dir),
+        'site_id' => $site_id,
+        'commentable' => boolean_to_string($conf['newcat_default_commentable']),
+        'status' => 'private',
+        'visible' => boolean_to_string($conf['newcat_default_visible']),
+      );
+
+      $parent_path = dirname($fulldir);
+      if (isset($db_fulldirs[$parent_path]))
+      {
+        $parent = $db_fulldirs[$parent_path];
+        $insert['id_uppercat'] = $parent;
+        $insert['uppercats'] = $db_categories[$parent]['uppercats'].','.$insert['id'];
+        $insert['rank'] = $next_rank[$parent]++;
+        $insert['global_rank'] = $db_categories[$parent]['global_rank'].'.'.$insert['rank'];
+        if ((string)$db_categories[$parent]['visible'] === 'false')
+        {
+          $insert['visible'] = 'false';
+        }
+      }
+      else
+      {
+        $insert['uppercats'] = (string)$insert['id'];
+        $insert['rank'] = $next_rank['NULL']++;
+        $insert['global_rank'] = (string)$insert['rank'];
+      }
+
+      $category_inserts[] = $insert;
+      $db_categories[$insert['id']] = array(
+        'id' => $insert['id'],
+        'id_uppercat' => $insert['id_uppercat'] ?? null,
+        'uppercats' => $insert['uppercats'],
+        'global_rank' => $insert['global_rank'],
+        'status' => 'private',
+        'visible' => $insert['visible'],
+      );
+      $db_fulldirs[$fulldir] = $insert['id'];
+      $next_rank[$insert['id']] = 1;
     }
 
-    $conf['newcat_default_status'] = 'private';
-    $_SERVER['REQUEST_METHOD'] = 'POST';
-    $_GET = array(
-      'page' => 'site_update',
-      'site' => $site_id,
-    );
-    $_POST = array(
-      'sync' => 'files',
-      'display_info' => 1,
-      'privacy_level' => 0,
-      'sync_meta' => 1,
-      'simulate' => 0,
-      'subcats-included' => 1,
-      'bratonien_connector' => 1,
-      'submit' => 1,
-    );
+    if ($category_inserts)
+    {
+      mass_inserts(
+        CATEGORIES_TABLE,
+        array('id','dir','name','site_id','id_uppercat','uppercats','commentable','visible','status','rank','global_rank'),
+        $category_inserts
+      );
+      $category_ids = array_map(function ($row) { return (int)$row['id']; }, $category_inserts);
+      pwg_activity('album', $category_ids, 'add', array('sync'=>true));
+      add_permission_on_category($category_ids, get_admins());
+      $counts['new_categories'] = count($category_ids);
+    }
 
-    ob_start();
-    include(PHPWG_ROOT_PATH.'admin/site_update.php');
-    $output = (string)ob_get_clean();
+    $to_delete_categories = array();
+    foreach (array_diff(array_keys($db_fulldirs), $fs_fulldirs) as $fulldir)
+    {
+      $to_delete_categories[] = (int)$db_fulldirs[$fulldir];
+      unset($db_fulldirs[$fulldir]);
+    }
+    if ($to_delete_categories)
+    {
+      delete_categories($to_delete_categories);
+      $counts['del_categories'] = count($to_delete_categories);
+    }
+
+    // -----------------------------------------------------------------
+    // Files / physical images.
+    // -----------------------------------------------------------------
+    $fs = $site_reader->get_elements($basedir);
+    $cat_ids = array_diff(array_keys($db_categories), $to_delete_categories);
+    $db_elements = array();
+    if ($cat_ids)
+    {
+      $query = '\nSELECT id, path\n  FROM '.IMAGES_TABLE.'\n  WHERE storage_category_id IN ('.implode(',', array_map('intval', $cat_ids)).')';
+      $db_elements = simple_hash_from_query($query, 'id', 'path');
+    }
+
+    $next_element_id = pwg_db_nextval('id', IMAGES_TABLE);
+    $image_inserts = array();
+    $image_links = array();
+    $format_inserts = array();
+    $new_image_ids = array();
+
+    foreach (array_diff(array_keys($fs), $db_elements) as $path)
+    {
+      $dirname = dirname($path);
+      if (!isset($db_fulldirs[$dirname]))
+      {
+        continue;
+      }
+
+      $filename = basename($path);
+      if (!preg_match($conf['sync_chars_regex'], $filename))
+      {
+        bratonien_tools_nc_productive_error($errors, $path, 'PWG-UPDATE-1');
+        continue;
+      }
+
+      $id = $next_element_id++;
+      $image_inserts[] = array(
+        'id' => $id,
+        'file' => $filename,
+        'name' => get_name_from_file($filename),
+        'date_available' => $dbnow,
+        'path' => $path,
+        'representative_ext' => $fs[$path]['representative_ext'],
+        'storage_category_id' => $db_fulldirs[$dirname],
+        'added_by' => (int)$user['id'],
+      );
+      $image_links[] = array('image_id'=>$id, 'category_id'=>$db_fulldirs[$dirname]);
+      $new_image_ids[] = $id;
+
+      if (!empty($conf['enable_formats']) && !empty($fs[$path]['formats']))
+      {
+        foreach ($fs[$path]['formats'] as $ext => $filesize)
+        {
+          $format_inserts[] = array('image_id'=>$id, 'ext'=>$ext, 'filesize'=>$filesize);
+        }
+      }
+    }
+
+    if ($image_inserts)
+    {
+      mass_inserts(IMAGES_TABLE, array_keys($image_inserts[0]), $image_inserts);
+      mass_inserts(IMAGE_CATEGORY_TABLE, array_keys($image_links[0]), $image_links);
+      pwg_activity('photo', $new_image_ids, 'add', array('sync'=>true));
+      $counts['new_elements'] = count($image_inserts);
+    }
+    if ($format_inserts)
+    {
+      mass_inserts(IMAGE_FORMAT_TABLE, array_keys($format_inserts[0]), $format_inserts);
+      $counts['new_formats'] += count($format_inserts);
+    }
+
+    if (!empty($conf['enable_formats']) && $db_elements)
+    {
+      $db_elements_flip = array_flip($db_elements);
+      $existing_ids = array();
+      foreach (array_intersect_key($fs, $db_elements_flip) as $path => $unused)
+      {
+        $existing_ids[] = (int)$db_elements_flip[$path];
+      }
+
+      if ($existing_ids)
+      {
+        $db_formats = array();
+        $result = pwg_query('SELECT * FROM '.IMAGE_FORMAT_TABLE.' WHERE image_id IN ('.implode(',', $existing_ids).')');
+        while ($row = pwg_db_fetch_assoc($result))
+        {
+          $db_formats[$row['image_id']][$row['ext']] = $row['format_id'];
+        }
+
+        $formats_to_delete = array();
+        $formats_to_insert = array();
+        foreach ($existing_ids as $image_id)
+        {
+          $path = $db_elements[$image_id];
+          $known = $db_formats[$image_id] ?? array();
+          $present = $fs[$path]['formats'] ?? array();
+          foreach (array_diff_key($known, $present) as $format_id)
+          {
+            $formats_to_delete[] = (int)$format_id;
+          }
+          foreach (array_diff_key($present, $known) as $ext => $filesize)
+          {
+            $formats_to_insert[] = array('image_id'=>$image_id, 'ext'=>$ext, 'filesize'=>$filesize);
+          }
+        }
+
+        if ($formats_to_delete)
+        {
+          pwg_query('DELETE FROM '.IMAGE_FORMAT_TABLE.' WHERE format_id IN ('.implode(',', $formats_to_delete).')');
+          $counts['del_formats'] = count($formats_to_delete);
+        }
+        if ($formats_to_insert)
+        {
+          mass_inserts(IMAGE_FORMAT_TABLE, array_keys($formats_to_insert[0]), $formats_to_insert);
+          $counts['new_formats'] += count($formats_to_insert);
+        }
+      }
+    }
+
+    $to_delete_elements = array();
+    foreach (array_diff($db_elements, array_keys($fs)) as $path)
+    {
+      $id = array_search($path, $db_elements, true);
+      if ($id !== false)
+      {
+        $to_delete_elements[] = (int)$id;
+      }
+    }
+    if ($to_delete_elements)
+    {
+      delete_elements($to_delete_elements);
+      $counts['del_elements'] = count($to_delete_elements);
+    }
+
+    update_category('all');
+    update_global_rank();
+
+    // -----------------------------------------------------------------
+    // File attributes.
+    // -----------------------------------------------------------------
+    $files = get_filelist('', $site_id, true, false);
+    $updates = array();
+    foreach ($files as $id => $file)
+    {
+      $data = $site_reader->get_element_update_attributes($file['path']);
+      if (!is_array($data))
+      {
+        continue;
+      }
+      $data['id'] = $id;
+      $updates[] = $data;
+    }
+    if ($updates)
+    {
+      mass_updates(
+        IMAGES_TABLE,
+        array('primary'=>array('id'), 'update'=>$site_reader->get_update_attributes()),
+        $updates
+      );
+    }
+    $counts['upd_elements'] = count($updates);
+
+    // -----------------------------------------------------------------
+    // Metadata: same default as core sync, only not-yet-synchronized files.
+    // -----------------------------------------------------------------
+    $metadata_files = get_filelist('', $site_id, true, true);
+    $counts['metadata_candidates'] = count($metadata_files);
+    $metadata_updates = array();
+    $tags_of = array();
+
+    foreach ($metadata_files as $id => $element_infos)
+    {
+      $data = $site_reader->get_element_metadata($element_infos);
+      if (!is_array($data))
+      {
+        bratonien_tools_nc_productive_error($errors, $element_infos['path'], 'PWG-ERROR-NO-FS');
+        continue;
+      }
+
+      $data['date_metadata_update'] = $dbnow;
+      $data['id'] = $id;
+      $metadata_updates[] = $data;
+
+      foreach (array('keywords','tags') as $key)
+      {
+        if (!isset($data[$key]))
+        {
+          continue;
+        }
+        $tags_of[$id] = $tags_of[$id] ?? array();
+        foreach (explode(',', $data[$key]) as $tag_name)
+        {
+          $tags_of[$id][] = tag_id_from_tag_name($tag_name);
+        }
+      }
+    }
+
+    if ($metadata_updates)
+    {
+      mass_updates(
+        IMAGES_TABLE,
+        array(
+          'primary'=>array('id'),
+          'update'=>array_unique(array_merge(
+            array_diff($site_reader->get_metadata_attributes(), array('keywords','tags')),
+            array('date_metadata_update')
+          )),
+        ),
+        $metadata_updates,
+        MASS_UPDATES_SKIP_EMPTY
+      );
+    }
+    if ($tags_of)
+    {
+      set_tags_of($tags_of);
+    }
+    $counts['metadata_updated'] = count($metadata_updates);
   }
   catch (Throwable $e)
   {
-    if (ob_get_level() > 0)
-    {
-      ob_end_clean();
-    }
-    return new PwgError(500, 'Piwigo core synchronization failed: '.$e->getMessage());
-  }
-  finally
-  {
-    $_GET = $saved_get;
-    $_POST = $saved_post;
-
-    if ($saved_template_dirs !== null && is_object($template) && isset($template->smarty))
-    {
-      $template->smarty->setTemplateDir($saved_template_dirs);
-    }
-
-    if ($saved_default_status === null)
-    {
-      unset($conf['newcat_default_status']);
-    }
-    else
-    {
-      $conf['newcat_default_status'] = $saved_default_status;
-    }
-    if ($saved_request_method === null)
-    {
-      unset($_SERVER['REQUEST_METHOD']);
-    }
-    else
-    {
-      $_SERVER['REQUEST_METHOD'] = $saved_request_method;
-    }
+    return new PwgError(500, 'Bratonien direct synchronization failed: '.$e->getMessage());
   }
 
   return array(
     'mode' => 'productive',
+    'engine' => 'bratonien-direct',
     'approved_piwigo_version' => '16.4.0',
     'piwigo_version' => $piwigo_version,
     'site_id' => $site_id,
-    'counts' => is_array($counts) ? $counts : array(),
+    'site_url' => $site_url,
+    'counts' => $counts,
+    'errors' => $errors,
+    'error_count' => count($errors),
     'database_writes' => true,
-    'core_output_bytes' => strlen($output),
     'username' => isset($user['username']) ? (string)$user['username'] : '',
     'status' => isset($user['status']) ? (string)$user['status'] : '',
   );