diff --git a/api/etemplate.php b/api/etemplate.php
new file mode 100644
index 0000000000..8f47eabfd7
--- /dev/null
+++ b/api/etemplate.php
@@ -0,0 +1,125 @@
+<?php
+/**
+ * API: loading for web-components modified eTemplate from server
+ *
+ * Usage: /egroupware/api/etemplate.php/<app>/templates/default/<name>.xet
+ *
+ * @link https://www.egroupware.org
+ * @author Ralf Becker <rb@egroupware-org>
+ * @package api
+ * @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
+ */
+
+use EGroupware\Api;
+
+// add et2- prefix to following widgets/tags
+/* disabling v/hbox replacement for now as it fails with nextmatch headers
+const ADD_ET2_PREFIX_REGEXP = '#(\s|^|>)<((/?)([vh]?box|button))(\s|/?>)#m';*/
+const ADD_ET2_PREFIX_REGEXP = '#(\s|^|>)<((/?)(box|button))(\s|/?>)#m';
+const ADD_ET2_PREFIX_REPLACE = '$1<$3et2-$4$5';
+
+// switch evtl. set output-compression off, as we cant calculate a Content-Length header with transparent compression
+ini_set('zlib.output_compression', 0);
+
+$GLOBALS['egw_info'] = array(
+	'flags' => array(
+		'currentapp' => 'api',
+		'noheader' => true,
+		// misuse session creation callback to send the template, in case we have no session
+		'autocreate_session_callback' => 'send_template',
+		'nocachecontrol' => true,
+	)
+);
+
+$start = microtime(true);
+include '../header.inc.php';
+
+send_template();
+
+function send_template()
+{
+	$header_include = microtime(true);
+
+	// release session, as we don't need it and it blocks parallel requests
+	$GLOBALS['egw']->session->commit_session();
+
+	header('Content-Type: application/xml; charset=UTF-8');
+
+	//$path = EGW_SERVER_ROOT.$_SERVER['PATH_INFO'];
+	// check for customized template in VFS
+	list(, $app, , $template, $name) = explode('/', $_SERVER['PATH_INFO']);
+	$path = Api\Etemplate::rel2path(Api\Etemplate::relPath($app.'.'.basename($name, '.xet'), $template));
+	if (empty($path) || !file_exists($path) || !is_readable($path))
+	{
+		http_response_code(404);
+		exit;
+	}
+	/* disable caching for now, as you need to delete the cache, once you change ADD_ET2_PREFIX_REGEXP
+	$cache = $GLOBALS['egw_info']['server']['temp_dir'].'/egw_cache/eT2-Cache-'.$GLOBALS['egw_info']['server']['install_id'].$_SERVER['PATH_INFO'];
+	if (file_exists($cache) && filemtime($cache) > filemtime($path) &&
+		($str = file_get_contents($cache)) !== false)
+	{
+		$cache_read = microtime(true);
+	}
+	else*/if (($str = file_get_contents($path)) !== false)
+	{
+		// fix <menulist...><menupopup type="select-*"/></menulist> --> <select type="select-*" .../>
+		$str = preg_replace('#<menulist([^>]*)>[\r\n\s]*<menupopup([^>]+>)[\r\n\s]*</menulist>#', '<select$1$2', $str);
+
+		// if there are multiple tags on one line, we need to run the regexp multiple times (eg. twice for the following example)
+		//$str = "<overlay>\n<template name='test'>\n\t<!-- this is a comment -->\n\t<box><button id='test'/></box>\n</template>\n</overlay>\n";
+		$iterations = 0;
+		do
+		{
+			$iterations++;
+			$original = $str;
+			$str = preg_replace(ADD_ET2_PREFIX_REGEXP, ADD_ET2_PREFIX_REPLACE, $original);
+		} while (strlen($str) !== strlen($original) || $str !== $original);
+		header('X-Required-Replace-Iterations: ' . ($iterations - 1));
+
+		$processing = microtime(true);
+
+		if (isset($cache) && (file_exists($cache_dir=dirname($cache)) || mkdir($cache_dir, 0755, true)))
+		{
+			file_put_contents($cache, $str);
+		}
+	}
+	// stop here for not existing file path-traversal for both file and cache here
+	if (empty($str) || strpos($path, '..') !== false)
+	{
+		http_response_code(404);
+		exit;
+	}
+
+	// headers to allow caching, egw_framework specifies etag on url to force reload, even with Expires header
+	Api\Session::cache_control(86400);    // cache for one day
+	$etag = '"' . md5($str) . '"';
+	Header('ETag: ' . $etag);
+
+	// if servers send a If-None-Match header, response with 304 Not Modified, if etag matches
+	if (isset($_SERVER['HTTP_IF_NONE_MATCH']) && $_SERVER['HTTP_IF_NONE_MATCH'] === $etag)
+	{
+		header("HTTP/1.1 304 Not Modified");
+		exit;
+	}
+
+	// we run our own gzip compression, to set a correct Content-Length of the encoded content
+	if (function_exists('gzencode') && in_array('gzip', explode(',', $_SERVER['HTTP_ACCEPT_ENCODING']), true))
+	{
+		$gzip_start = microtime(true);
+		$str = gzencode($str);
+		header('Content-Encoding: gzip');
+		$gziping = microtime(true)-$gzip_start;
+	}
+	header('X-Timing: header-include='.number_format($header_include-$GLOBALS['start'], 3).
+		(empty($processing) ? ', cache-read='.number_format($cache_read-$header_include, 3) :
+			', processing='.number_format($processing-$header_include, 3)).
+		(!empty($gziping) ? ', gziping='.number_format($gziping, 3) : '').
+		', total='.number_format(microtime(true)-$GLOBALS['start'], 3));
+
+	// Content-Length header is important, otherwise browsers dont cache!
+	Header('Content-Length: ' . bytes($str));
+	echo $str;
+
+	exit;	// stop further processing eg. redirect to login
+}
\ No newline at end of file
diff --git a/api/src/Etemplate/Widget/Template.php b/api/src/Etemplate/Widget/Template.php
index 5b9c30435f..490eb6d591 100644
--- a/api/src/Etemplate/Widget/Template.php
+++ b/api/src/Etemplate/Widget/Template.php
@@ -205,29 +205,15 @@ class Template extends Etemplate\Widget
 	/**
 	 * Convert relative template path from relPath to an url incl. cache-buster modification time postfix
 	 *
+	 * This adds the server-side modification of eTemplates for web-components /api/etemplate.php.
+	 *
 	 * @param string $path
 	 * @return string url
 	 */
 	public static function rel2url($path)
 	{
-		if ($path)
-		{
-			if ($path[0] === '/')
-			{
-				$url = $GLOBALS['egw_info']['server']['webserver_url'].$path.'?'.filemtime(self::rel2path($path));
-			}
-			else
-			{
-				$url = Api\Vfs::download_url($path);
-
-				if ($url[0] == '/') $url = Api\Framework::link($url);
-
-				// mtime postfix has to use '?download=', as our WebDAV treats everything else literal and not ignore them like Apache for static files!
-				$url .= '?download='.filemtime($path);
-			}
-		}
-		//error_log(__METHOD__."('$path') returning $url");
-		return $url;
+		return $GLOBALS['egw_info']['server']['webserver_url'].'/api/etemplate.php'.
+			($path[0] === '/' ? $path : Api\Vfs::parse_url($path, PHP_URL_PATH)).'?'.filemtime(self::rel2path($path));
 	}
 
 	/**