fix(models): guard Gemini.client_kwargs against missing-field AttributeError

PiperOrigin-RevId: 951961168

Author: google-genai-bot

src/google/adk/models/google_llm.py

@@ -357,8 +357,9 @@ def api_client(self) -> Client:
     if self.model.startswith('projects/'):
       kwargs['enterprise'] = True
 
-    if self.client_kwargs:
-      kwargs.update(self.client_kwargs)
+    client_kwargs = getattr(self, 'client_kwargs', None)
+    if client_kwargs:
+      kwargs.update(client_kwargs)
 
     return Client(**kwargs)
 
@@ -405,8 +406,9 @@ def _live_api_client(self) -> Client:
     if self.model.startswith('projects/'):
       kwargs['enterprise'] = True
 
-    if self.client_kwargs:
-      kwargs.update(self.client_kwargs)
+    client_kwargs = getattr(self, 'client_kwargs', None)
+    if client_kwargs:
+      kwargs.update(client_kwargs)
 
     return Client(**kwargs)
 

tests/unittests/models/test_google_llm.py

@@ -242,6 +242,20 @@ def test_gemini_repr_excludes_client_kwargs():
   assert "client_kwargs" not in repr_str
 
 
+def test_gemini_api_client_when_client_kwargs_missing_from_dict():
+  model = Gemini(model="gemini-2.5-flash")
+  model.__dict__.pop("client_kwargs", None)
+  assert "client_kwargs" not in model.__dict__
+
+  with mock.patch("google.genai.Client", autospec=True) as mock_client:
+    _ = model.api_client
+    mock_client.assert_called_once()
+
+  with mock.patch("google.genai.Client", autospec=True) as mock_client:
+    _ = model._live_api_client
+    mock_client.assert_called_once()
+
+
 def test_client_version_header():
   model = Gemini(model="gemini-2.5-flash")
   client = model.api_client