Fix activity input serialization

Author: AnatoliB

samples-v2/openai_agents/_invoke_model_activity.py

@@ -162,6 +162,49 @@ def to_json(self) -> str:
         """Convert the ActivityModelInput to a JSON string."""
         return to_json(self).decode('utf-8')
 
+    @classmethod
+    def from_json(cls, json_str: str) -> 'ActivityModelInput':
+        """Create an ActivityModelInput instance from a JSON string."""
+        import json
+        data = json.loads(json_str)
+        
+        # Convert complex types back from dictionaries
+        if 'model_settings' in data and isinstance(data['model_settings'], dict):
+            data['model_settings'] = ModelSettings(**data['model_settings'])
+        
+        if 'tracing' in data and isinstance(data['tracing'], int):
+            data['tracing'] = ModelTracingInput(data['tracing'])
+        
+        # Convert tool inputs back to proper types
+        if 'tools' in data and data['tools']:
+            converted_tools = []
+            for tool_data in data['tools']:
+                if isinstance(tool_data, dict):
+                    # Check the tool type and convert accordingly
+                    if 'name' in tool_data and 'description' in tool_data and 'params_json_schema' in tool_data:
+                        # FunctionToolInput
+                        converted_tools.append(FunctionToolInput(**tool_data))
+                    elif 'tool_config' in tool_data:
+                        # HostedMCPToolInput
+                        converted_tools.append(HostedMCPToolInput(**tool_data))
+                    else:
+                        # For other tool types like FileSearchTool, WebSearchTool, etc.
+                        # These might be already properly serialized/deserialized by pydantic_core
+                        converted_tools.append(tool_data)
+                else:
+                    converted_tools.append(tool_data)
+            data['tools'] = converted_tools
+        
+        # Convert handoffs back to proper types
+        if 'handoffs' in data and data['handoffs']:
+            data['handoffs'] = [HandoffInput(**handoff) for handoff in data['handoffs']]
+        
+        # Convert output_schema back to proper type
+        if 'output_schema' in data and data['output_schema'] and isinstance(data['output_schema'], dict):
+            data['output_schema'] = AgentOutputSchemaInput(**data['output_schema'])
+        
+        return cls(**data)
+
 
 class ModelActivity:
     """Class wrapper for model invocation activities to allow model customization. By default, we use an OpenAIProvider with retries disabled.

samples-v2/openai_agents/durable_model_stub.py

@@ -1,7 +1,17 @@
 from __future__ import annotations
-from _invoke_model_activity import ActivityModelInput, ModelTracingInput
+from _invoke_model_activity import (
+    ActivityModelInput, 
+    ModelTracingInput, 
+    ToolInput, 
+    HostedMCPToolInput, 
+    FunctionToolInput, 
+    HandoffInput, 
+    AgentOutputSchemaInput
+)
+from orchestrator_exceptions import OrchestratorYielded
 import azure.durable_functions as df
 
+import json
 import logging
 from typing import Optional
 
@@ -119,9 +129,12 @@ def make_tool_info(tool: Tool) -> ToolInput:
             prompt=prompt,
         )
 
-        activity_output =self.durable_orchestration_context.call_activity(
+        # Serialize activity_input to JSON
+        activity_input_json = activity_input.to_json()
+
+        activity_output = self.durable_orchestration_context.call_activity(
             "invoke_model_activity",
-            activity_input
+            activity_input_json
         )
 
         raise OrchestratorYielded(activity_output)

samples-v2/openai_agents/function_app.py

@@ -4,6 +4,27 @@
 
 from agents.run import set_default_agent_runner
 from durable_openai_runner import DurableOpenAIRunner
+from orchestrator_exceptions import OrchestratorYielded
+
+from agents import (
+    AgentOutputSchemaBase,
+    CodeInterpreterTool,
+    FileSearchTool,
+    FunctionTool,
+    Handoff,
+    HostedMCPTool,
+    ImageGenerationTool,
+    ModelProvider,
+    ModelResponse,
+    ModelSettings,
+    ModelTracing,
+    OpenAIProvider,
+    RunContextWrapper,
+    Tool,
+    TResponseInputItem,
+    UserError,
+    WebSearchTool,
+)
 
 app = func.FunctionApp(http_auth_level=func.AuthLevel.FUNCTION)
 
@@ -28,8 +49,13 @@ def basic_hello_world_orchestrator(context):
         yield e.activity_output
 
 @app.activity_trigger(input_name="input")
-def invoke_model_activity(input: Any):
+async def invoke_model_activity(input: str):
     # Instantiate ModelActivity
     from _invoke_model_activity import ModelActivity, ActivityModelInput
+    
+    # Deserialize input string into ActivityModelInput object
+    activity_input = ActivityModelInput.from_json(input)
+    
     model_activity = ModelActivity()
-    return model_activity.invoke_model_activity(input)
+    return await model_activity.invoke_model_activity(activity_input)
+