diff --git a/config.py b/config.py
index 90d1a8b..2a8f86a 100644
--- a/config.py
+++ b/config.py
@@ -203,6 +203,19 @@ class AlltalkTTSEnginesConfig(AbstractConfig):
     def save(self, path: Path | str | None = None):
         self._save_file(path)
 
+    def is_valid_engine(self, engine_name):
+        return engine_name in self.get_engine_names_available()
+
+    def change_engine(self, requested_engine):
+        if requested_engine == self.engine_loaded:
+            return self
+        for engine in self.engines_available:
+            if engine["name"] == requested_engine:
+                self.engine_loaded = requested_engine
+                self.selected_model = engine["selected_model"]
+                return self
+        return self
+
 
 class AlltalkConfig(AbstractConfig):
     __instance = None
@@ -234,6 +247,9 @@ class AlltalkConfig(AbstractConfig):
         AlltalkConfig.__instance._reload_on_change()
         return AlltalkConfig.__instance
 
+    def get_output_directory(self):
+        return self.__this_dir / self.output_folder
+
     def save(self, path: Path | str | None = None):
         self._save_file(path, lambda o: o.__dict__)
 
@@ -250,5 +266,4 @@ class AlltalkConfig(AbstractConfig):
         self.theme.clazz = data.theme.__dict__["class"]
 
         # As a side effect, create the output directory:
-        output_directory = self.__this_dir / self.output_folder
-        output_directory.mkdir(parents=True, exist_ok=True)
+        self.get_output_directory().mkdir(parents=True, exist_ok=True)
diff --git a/test/test_config.py b/test/test_config.py
index 0bc9c8a..39a46ba 100644
--- a/test/test_config.py
+++ b/test/test_config.py
@@ -9,8 +9,8 @@ from config import AlltalkConfig, AlltalkTTSEnginesConfig
 class TestAlltalkConfig(unittest.TestCase):
 
     def setUp(self):
-        self.config = AlltalkConfig.get_instance()
-        self.ttsEnginesConfig = AlltalkTTSEnginesConfig.get_instance()
+        self.config = AlltalkConfig.get_instance().reload()
+        self.ttsEnginesConfig = AlltalkTTSEnginesConfig.get_instance().reload()
 
     def test_default_config_path(self):
         expected_config_path = Path(__file__).parent.parent.resolve() / "confignew.json"
@@ -127,6 +127,17 @@ class TestAlltalkConfig(unittest.TestCase):
         self.assertEqual(self.ttsEnginesConfig.selected_model, "piper")
         self.assertListEqual(self.ttsEnginesConfig.get_engine_names_available(), ["parler", "piper", "vits", "xtts", "f5tts"])
 
+    def test_is_valid_engine(self):
+        for engine in ["parler", "piper", "vits", "xtts", "f5tts"]:
+            self.assertTrue(self.ttsEnginesConfig.is_valid_engine(engine))
+
+        self.assertFalse(self.ttsEnginesConfig.is_valid_engine("foo"))
+
+    def test_change_tts_engine(self):
+        self.ttsEnginesConfig.change_engine("vits")
+        self.assertEqual(self.ttsEnginesConfig.engine_loaded, "vits")
+        self.assertEqual(self.ttsEnginesConfig.selected_model, "vits - tts_models--en--vctk--vits")
+
     def test_tts_engines_default_config_path(self):
         expected_config_path = os.path.join(Path(__file__).parent.parent.resolve(), "system", "tts_engines", "tts_engines.json")
         self.assertEqual(self.ttsEnginesConfig.get_config_path(), Path(expected_config_path))