diff --git a/includes/menu/Group.php b/includes/menu/Group.php
index 0a5eb10..8429179 100644
--- a/includes/menu/Group.php
+++ b/includes/menu/Group.php
@@ -27,7 +27,7 @@ use DomainException;
  */
 class Group {
 	/**
-	 * @var MenuEntry[]
+	 * @var IMenuEntry[]
 	 */
 	private $entries = [];
 
@@ -46,14 +46,14 @@ class Group {
 	 * @return array
 	 */
 	public function getEntries() {
-		$entryPresenter = function ( MenuEntry $entry ) {
+		$entryPresenter = function ( IMenuEntry $entry ) {
 			$result = [
 				'name' => $entry->getName(),
 				'components' => $entry->getComponents(),
 			];
-
-			if ( $entry->isJSOnly() ) {
-				$result['class'] = 'jsonly';
+			$classes = $entry->getCSSClasses();
+			if ( $classes ) {
+				$result[ 'class' ] = implode( ' ', $classes );
 			}
 
 			return $result;
@@ -74,6 +74,16 @@ class Group {
 		}
 	}
 
+	/**
+	 * Insert new menu entry
+	 * @param IMenuEntry $entry
+	 * @throws DomainException When the entry already exists
+	 */
+	public function insertEntry( IMenuEntry $entry ) {
+		$this->throwIfNotUnique( $entry->getName() );
+		$this->entries[] = $entry;
+	}
+
 	/**
 	 * Insert an entry into the menu.
 	 *
@@ -119,7 +129,6 @@ class Group {
 	 */
 	public function insertAfter( $targetName, $name, $isJSOnly = false ) {
 		$this->throwIfNotUnique( $name );
-
 		$index = $this->search( $targetName );
 
 		if ( $index === -1 ) {
diff --git a/includes/menu/IMenuEntry.php b/includes/menu/IMenuEntry.php
new file mode 100644
index 0000000..439b7c9
--- /dev/null
+++ b/includes/menu/IMenuEntry.php
@@ -0,0 +1,48 @@
+<?php
+/**
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+namespace MediaWiki\Minerva\Menu;
+
+/**
+ * Model for a menu entry.
+ */
+interface IMenuEntry {
+
+	/**
+	 * Get the menu entry name/identifier
+	 * @return string
+	 */
+	public function getName();
+
+	/**
+	 * Get the CSS classes that should be applied to the element
+	 * @return string[]
+	 */
+	public function getCSSClasses(): array;
+
+	/**
+	 * Returns the list of components of the menu entry
+	 *
+	 * Each component is an array with:
+	 *  - text  -> text to show
+	 *  - href  -> href attribute
+	 *  - class -> css class applied to it
+	 * @return array
+	 */
+	public function getComponents(): array;
+
+}
diff --git a/includes/menu/MenuEntry.php b/includes/menu/MenuEntry.php
index 403c2a1..c384bc7 100644
--- a/includes/menu/MenuEntry.php
+++ b/includes/menu/MenuEntry.php
@@ -20,7 +20,7 @@ namespace MediaWiki\Minerva\Menu;
 /**
  * Model for a menu entry.
  */
-class MenuEntry {
+class MenuEntry implements IMenuEntry {
 	private $name;
 	private $isJSOnly;
 	private $components;
@@ -43,19 +43,22 @@ class MenuEntry {
 	}
 
 	/**
-	 * Gets whether the entry should only be shown if JavaScript is disabled
-	 * in the client.
+	 * Return the CSS classes applied to the Menu element
 	 *
-	 * @return bool
+	 * @return array
 	 */
-	public function isJSOnly() {
-		return $this->isJSOnly;
+	public function getCSSClasses(): array {
+		$classes = [];
+		if ( $this->isJSOnly ) {
+			$classes[] = 'jsonly';
+		}
+		return $classes;
 	}
 
 	/**
 	 * @return array
 	 */
-	public function getComponents() {
+	public function getComponents(): array {
 		return $this->components;
 	}
 
diff --git a/tests/phpunit/menu/MenuEntryTest.php b/tests/phpunit/menu/MenuEntryTest.php
index 418e4a5..5563175 100644
--- a/tests/phpunit/menu/MenuEntryTest.php
+++ b/tests/phpunit/menu/MenuEntryTest.php
@@ -13,7 +13,7 @@ class MenuEntryTest extends \MediaWikiTestCase {
 	/**
 	 * @covers ::__construct
 	 * @covers ::getName()
-	 * @covers ::isJSOnly()
+	 * @covers ::getCSSClasses()
 	 * @covers ::getComponents()
 	 */
 	public function testMenuEntryConstruction() {
@@ -21,7 +21,7 @@ class MenuEntryTest extends \MediaWikiTestCase {
 		$isJSOnly = true;
 		$entry = new MenuEntry( $name, $isJSOnly );
 		$this->assertSame( $name, $entry->getName() );
-		$this->assertSame( $isJSOnly, $entry->isJSOnly() );
+		$this->assertArrayEquals( [ 'jsonly' ], $entry->getCSSClasses() );
 		$this->assertSame( [], $entry->getComponents() );
 	}
 }