Fix model response serialization

Author: AnatoliB

samples-v2/openai_agents/activity_call_tracker.py

@@ -1,3 +1,4 @@
+import json
 from azure.durable_functions.models.DurableOrchestrationContext import DurableOrchestrationContext
 from yield_exception import YieldException
 
@@ -20,4 +21,7 @@ def call_activity(self, activity_name, input: str):
         else:
             # yield later
             self.tasks_to_yield.append(task)
-            return completed_tasks[self.activities_called - 1].Result
+
+            result_json = completed_tasks[self.activities_called - 1].Result
+            result = json.loads(result_json)
+            return result

samples-v2/openai_agents/durable_model_stub.py

@@ -131,8 +131,10 @@ def make_tool_info(tool: Tool) -> ToolInput:
 
         activity_input_json = activity_input.to_json()
 
-        result = self.activity_call_tracker.call_activity("invoke_model_activity", activity_input_json)
-        return result
+        response = self.activity_call_tracker.call_activity("invoke_model_activity", activity_input_json)
+        json_response = json.loads(response)
+        model_response = ModelResponse(**json_response)
+        return model_response
 
     def stream_response(
         self,

samples-v2/openai_agents/function_app.py

@@ -70,6 +70,5 @@ async def invoke_model_activity(input: str):
     model_activity = ModelActivity()
     result = await model_activity.invoke_model_activity(activity_input)
 
-    result_json = to_json(result).decode('utf-8')
-    return result_json
- 
+    json_obj = ModelResponse.__pydantic_serializer__.to_json(result)
+    return json_obj.decode()