diff --git a/src/codeinterpreterapi/crew/custom_agent.py b/src/codeinterpreterapi/crew/custom_agent.py
index b8fa932d..08fb7d5c 100644
--- a/src/codeinterpreterapi/crew/custom_agent.py
+++ b/src/codeinterpreterapi/crew/custom_agent.py
@@ -27,7 +27,6 @@ def __init__(self, agent_executor: Any, **data):
 
     def interpolate_inputs(self, inputs: Dict[str, Any]) -> None:
         """Interpolate inputs into the task description and expected output."""
-        print("interpolate_inputs inputs=", inputs)
         super().interpolate_inputs(inputs)
 
     def execute_task(self, task: Any, context: Optional[str] = None, tools: Optional[List[Any]] = None) -> str:
@@ -45,6 +44,7 @@ def execute_task(self, task: Any, context: Optional[str] = None, tools: Optional
         input_dict["message"] = "タスクを実行してください。\n" + task.expected_output
         result = self.agent_executor.invoke(input=input_dict)
         result_str = MultiConverter.to_str(result)
+        print("execute_task result(type)=", type(result_str))
         print("execute_task result=", result_str)
 
         # TODO: return full dict when crewai is updated
diff --git a/src/codeinterpreterapi/schema.py b/src/codeinterpreterapi/schema.py
index 4dd3638b..7a754931 100644
--- a/src/codeinterpreterapi/schema.py
+++ b/src/codeinterpreterapi/schema.py
@@ -116,7 +116,8 @@ class CodeInterpreterResponse(AIMessage):
 
     files: Optional[list[File]] = []
     code_log: Optional[dict[str, str]] = []
-    agent_name: str = ""
+    agent_name: Optional[str] = ""
+    thought: Optional[str] = ""  # 中間的な思考
 
     def show(self) -> None:
         print("AI: ", self.content)
diff --git a/src/codeinterpreterapi/session.py b/src/codeinterpreterapi/session.py
index 0f9e24b0..23dc6d94 100644
--- a/src/codeinterpreterapi/session.py
+++ b/src/codeinterpreterapi/session.py
@@ -411,7 +411,7 @@ def generate_response_stream(
         self,
         user_msg: BaseMessageContent,
         files: list[File] = None,
-    ) -> Iterator[str]:
+    ) -> Iterator[CodeInterpreterResponse]:
         """Generate a Code Interpreter response based on the user's input."""
         if files is None:
             files = []
diff --git a/src/codeinterpreterapi/utils/multi_converter.py b/src/codeinterpreterapi/utils/multi_converter.py
index f2f0650b..a67e9b09 100644
--- a/src/codeinterpreterapi/utils/multi_converter.py
+++ b/src/codeinterpreterapi/utils/multi_converter.py
@@ -1,5 +1,6 @@
 from typing import Any, Dict, List
 
+from crewai.crews.crew_output import CrewOutput, TaskOutput
 from langchain_core.messages import AIMessageChunk
 
 
@@ -14,13 +15,16 @@ def to_str(input_obj: Any) -> str:
             if len(input_obj) > 0:
                 input_obj = MultiConverter._process_dict(input_obj[-1])
             else:
-                input_obj = ""
+                return "no output"
         elif isinstance(input_obj, Dict):
             input_obj = MultiConverter._process_dict(input_obj)
+        elif isinstance(input_obj, CrewOutput):
+            input_obj = MultiConverter._process_crew_output(input_obj)
         else:
+            print("MultiConverter to_str type(input_obj)=", type(input_obj))
             return str(input_obj)
 
-        # 再帰
+        # 確実にstr以外は念のため再帰
         return MultiConverter.to_str(input_obj)
 
     @staticmethod
@@ -43,3 +47,14 @@ def _process_dict(input_dict: Dict[str, Any]) -> str:
         keys = ["tool", "tool_input_obj", "log"]
         code_log_item = {key: str(input_dict[key]) for key in keys if key in input_dict}
         return str(code_log_item) if code_log_item else str(input_dict)
+
+    @staticmethod
+    def _process_crew_output(input_crew_output: CrewOutput) -> str:
+        # TODO: return json or
+        last_task_output: TaskOutput = input_crew_output.tasks_output[-1]
+        if last_task_output.json_dict:
+            return str(last_task_output.json_dict)
+        elif last_task_output.pydantic:
+            return str(last_task_output.pydantic)
+        else:
+            return last_task_output.raw