@@ -418,6 +418,31 @@ def test_clone(self):
         app_clone.set_up()
         assert app_clone._tmpl_attrs.get("runner") is not None
 
+    def test_clone_preserves_subclass(self):
+        class CustomAdkApp(reasoning_engines.AdkApp):
+            pass
+
+        app = CustomAdkApp(
+            agent=Agent(name=_TEST_AGENT_NAME, model=_TEST_MODEL),
+        )
+        assert isinstance(app.clone(), CustomAdkApp)
+
+    def test_clone_preserves_plugins_and_credential_service_builder(self):
+        def credential_service_builder():
+            return None
+
+        app = reasoning_engines.AdkApp(
+            agent=Agent(name=_TEST_AGENT_NAME, model=_TEST_MODEL),
+            plugins=["test_plugin"],
+            credential_service_builder=credential_service_builder,
+        )
+        app_clone = app.clone()
+        assert app_clone._tmpl_attrs.get("plugins") == ["test_plugin"]
+        assert (
+            app_clone._tmpl_attrs.get("credential_service_builder")
+            is credential_service_builder
+        )
+
     def test_register_operations(self):
         app = reasoning_engines.AdkApp(
             agent=Agent(name=_TEST_AGENT_NAME, model=_TEST_MODEL),
 
@@ -846,12 +846,16 @@ def clone(self):
         """Returns a clone of the ADK application."""
         import copy
 
-        return AdkApp(
+        return self.__class__(
             agent=copy.deepcopy(self._tmpl_attrs.get("agent")),
+            plugins=copy.deepcopy(self._tmpl_attrs.get("plugins")),
             enable_tracing=self._tmpl_attrs.get("enable_tracing"),
             session_service_builder=self._tmpl_attrs.get("session_service_builder"),
             artifact_service_builder=self._tmpl_attrs.get("artifact_service_builder"),
             memory_service_builder=self._tmpl_attrs.get("memory_service_builder"),
+            credential_service_builder=self._tmpl_attrs.get(
+                "credential_service_builder"
+            ),
             env_vars=self._tmpl_attrs.get("env_vars"),
         )