server: only write the XML cursor attribute when there is a next page

server/app/interfaces/base.py

@@ -129,7 +129,7 @@ def __init__(self, *args, content_type="application/xml", **kwargs):
 
     def serialize(self, obj: ResponseData, paging_metadata: Optional[PagingMetadata], stripped: bool) -> str:
         root_elem = etree.Element("response", nsmap=XML_NS_MAP)
-        if paging_metadata is not None:
+        if paging_metadata is not None and paging_metadata.cursor is not None:
             root_elem.set("cursor", str(paging_metadata.cursor))
         if isinstance(obj, Result):
             result_elem = self.result_to_xml(obj, **XML_NS_MAP)

server/test/interfaces/test_xml_paging_cursor.py

@@ -0,0 +1,34 @@
+# Copyright (c) 2026 the Eclipse BaSyx Authors
+#
+# This program and the accompanying materials are made available under the terms of the MIT License, available in
+# the LICENSE file of this project.
+#
+# SPDX-License-Identifier: MIT
+
+import unittest
+
+from app._config import API_BASE_PATH as BASE_PATH
+from app.interfaces.repository import WSGIApp
+from basyx.aas.adapter.aasx import DictSupplementaryFileContainer
+from basyx.aas.examples.data.example_aas import create_full_example
+from lxml import etree
+from werkzeug.test import Client
+
+
+class XmlPagingCursorTest(unittest.TestCase):
+    def setUp(self) -> None:
+        self.example_data = create_full_example()
+        app = WSGIApp(self.example_data, DictSupplementaryFileContainer())
+        self.client = Client(app)
+
+    def test_last_page_omits_cursor(self) -> None:
+        response = self.client.get(f"{BASE_PATH}/submodels?limit=100", headers={"Accept": "application/xml"})
+        self.assertEqual(200, response.status_code)
+        root = etree.fromstring(response.data)
+        self.assertIsNone(root.get("cursor"))
+
+    def test_next_page_has_cursor(self) -> None:
+        response = self.client.get(f"{BASE_PATH}/submodels?limit=1", headers={"Accept": "application/xml"})
+        self.assertEqual(200, response.status_code)
+        root = etree.fromstring(response.data)
+        self.assertEqual("2", root.get("cursor"))