Fix: #2936 - Prevent escaping of Latin characters in LLM response

src/google/adk/flows/llm_flows/_output_schema_processor.py

@@ -107,7 +107,9 @@ def get_structured_model_response(function_response_event: Event) -> str | None:
   for func_response in function_response_event.get_function_responses():
     if func_response.name == 'set_model_response':
       # Convert dict to JSON string
-      return json.dumps(func_response.response)
+      return json.dumps(
+        func_response.response, ensure_ascii=False
+      )
 
   return None
 

tests/unittests/flows/llm_flows/test_output_schema_processor.py

@@ -254,6 +254,41 @@ async def test_output_schema_helper_functions():
   assert extracted_json is None
 
 
+@pytest.mark.asyncio
+async def test_get_structured_model_response_with_non_ascii():
+  """Test get_structured_model_response with non-ASCII characters."""
+  from google.adk.events.event import Event
+  from google.adk.flows.llm_flows._output_schema_processor import (
+      get_structured_model_response,
+  )
+  from google.genai import types
+
+  # Test with a dictionary containing non-ASCII characters
+  test_dict = {'city': 'São Paulo'}
+  expected_json = '{"city": "São Paulo"}'
+
+  # Create a function response event
+  function_response_event = Event(
+      author='test_agent',
+      content=types.Content(
+          role='user',
+          parts=[
+              types.Part(
+                  function_response=types.FunctionResponse(
+                      name='set_model_response', response=test_dict
+                  )
+              )
+          ],
+      ),
+  )
+
+  # Get the structured response
+  extracted_json = get_structured_model_response(function_response_event)
+
+  # Assert that the output is the expected JSON string without escaped characters
+  assert extracted_json == expected_json
+
+
 @pytest.mark.asyncio
 async def test_end_to_end_integration():
   """Test the complete output schema with tools integration."""