diff --git a/metagpt/strategy/tot.py b/metagpt/strategy/tot.py
index a32cfdf40..4f33698bf 100644
--- a/metagpt/strategy/tot.py
+++ b/metagpt/strategy/tot.py
@@ -5,7 +5,7 @@
 import asyncio
 from typing import Any, List
 
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, ConfigDict, Field
 
 from metagpt.llm import LLM
 from metagpt.logs import logger
@@ -29,6 +29,8 @@ Output a list of jsons following the format:
 
 
 class ThoughtSolverBase(BaseModel):
+    model_config = ConfigDict(arbitrary_types_allowed=True)
+
     thought_tree: str = ""
     llm: BaseLLM = Field(default_factory=LLM, exclude=True)
     config: ThoughtSolverConfig = Field(default_factory=ThoughtSolverConfig)
diff --git a/requirements.txt b/requirements.txt
index 832b4c1c8..c04c6cc7f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -58,3 +58,4 @@ websockets~=12.0
 networkx~=3.2.1
 google-generativeai==0.3.1
 playwright==1.40.0
+anytree
diff --git a/tests/metagpt/strategy/__init__.py b/tests/metagpt/strategy/__init__.py
new file mode 100644
index 000000000..e95a9b4ed
--- /dev/null
+++ b/tests/metagpt/strategy/__init__.py
@@ -0,0 +1,7 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+"""
+@Time    : 2023/12/30 00:33
+@Author  : alexanderwu
+@File    : __init__.py
+"""
diff --git a/metagpt/strategy/examples/__init__.py b/tests/metagpt/strategy/examples/__init__.py
similarity index 100%
rename from metagpt/strategy/examples/__init__.py
rename to tests/metagpt/strategy/examples/__init__.py
diff --git a/metagpt/strategy/examples/creative_writing.py b/tests/metagpt/strategy/examples/creative_writing.py
similarity index 87%
rename from metagpt/strategy/examples/creative_writing.py
rename to tests/metagpt/strategy/examples/creative_writing.py
index 94efd9264..59a3c94d7 100644
--- a/metagpt/strategy/examples/creative_writing.py
+++ b/tests/metagpt/strategy/examples/creative_writing.py
@@ -3,8 +3,8 @@
 # @Author  : stellahong (stellahong@fuzhi.ai)
 # @Desc    :
 import re
+from typing import Dict
 
-from metagpt.strategy.prompt_templates.creative_writing import cot_prompt, vote_prompt
 from metagpt.strategy.tot import TreeofThought
 from metagpt.strategy.tot_schema import (
     BaseEvaluator,
@@ -12,6 +12,10 @@ from metagpt.strategy.tot_schema import (
     Strategy,
     ThoughtSolverConfig,
 )
+from tests.metagpt.strategy.prompt_templates.creative_writing import (
+    cot_prompt,
+    vote_prompt,
+)
 
 
 class TextGenParser(BaseParser):
@@ -31,8 +35,8 @@ class TextGenParser(BaseParser):
 
 
 class TextGenEvaluator(BaseEvaluator):
-    value_map = {"impossible": 0.001, "likely": 1, "sure": 20}  # TODO: ad hoc
-    status_map = {val: key for key, val in value_map.items()}
+    value_map: Dict[str, float] = {"impossible": 0.001, "likely": 1, "sure": 20}  # TODO: ad hoc
+    status_map: Dict = {val: key for key, val in value_map.items()}
 
     def __call__(self, evaluation: str, **kwargs) -> float:
         try:
@@ -59,7 +63,7 @@ class TextGenEvaluator(BaseEvaluator):
         return status
 
 
-if __name__ == "__main__":
+def test_creative_writing():
     import asyncio
 
     initial_prompt = """It isn't difficult to do a handstand if you just stand on your hands. It caught him off guard that space smelled of seared steak. When she didn’t like a guy who was trying to pick her up, she started using sign language. Each person who knows you has a different perception of who you are."""
diff --git a/metagpt/strategy/examples/game24.py b/tests/metagpt/strategy/examples/game24.py
similarity index 85%
rename from metagpt/strategy/examples/game24.py
rename to tests/metagpt/strategy/examples/game24.py
index 32e4ede02..c26c8da88 100644
--- a/metagpt/strategy/examples/game24.py
+++ b/tests/metagpt/strategy/examples/game24.py
@@ -3,8 +3,8 @@
 # @Author  : stellahong (stellahong@fuzhi.ai)
 # @Desc    :
 import re
+from typing import Dict
 
-from metagpt.strategy.prompt_templates.game24 import propose_prompt, value_prompt
 from metagpt.strategy.tot import TreeofThought
 from metagpt.strategy.tot_schema import (
     BaseEvaluator,
@@ -12,6 +12,7 @@ from metagpt.strategy.tot_schema import (
     Strategy,
     ThoughtSolverConfig,
 )
+from tests.metagpt.strategy.prompt_templates.game24 import propose_prompt, value_prompt
 
 
 class Game24Parser(BaseParser):
@@ -31,8 +32,8 @@ class Game24Parser(BaseParser):
 
 
 class Game24Evaluator(BaseEvaluator):
-    value_map = {"impossible": 0.001, "likely": 1, "sure": 20}  # TODO: ad hoc
-    status_map = {val: key for key, val in value_map.items()}
+    value_map: Dict[str, float] = {"impossible": 0.001, "likely": 1, "sure": 20}  # TODO: ad hoc
+    status_map: Dict = {val: key for key, val in value_map.items()}
 
     def __call__(self, evaluation: str, **kwargs) -> float:
         try:
@@ -51,7 +52,7 @@ class Game24Evaluator(BaseEvaluator):
         return status
 
 
-if __name__ == "__main__":
+def test_game24():
     import asyncio
 
     initial_prompt = """4 5 6 10"""
diff --git a/metagpt/strategy/prompt_templates/__init__.py b/tests/metagpt/strategy/prompt_templates/__init__.py
similarity index 100%
rename from metagpt/strategy/prompt_templates/__init__.py
rename to tests/metagpt/strategy/prompt_templates/__init__.py
diff --git a/metagpt/strategy/prompt_templates/creative_writing.py b/tests/metagpt/strategy/prompt_templates/creative_writing.py
similarity index 100%
rename from metagpt/strategy/prompt_templates/creative_writing.py
rename to tests/metagpt/strategy/prompt_templates/creative_writing.py
diff --git a/metagpt/strategy/prompt_templates/game24.py b/tests/metagpt/strategy/prompt_templates/game24.py
similarity index 100%
rename from metagpt/strategy/prompt_templates/game24.py
rename to tests/metagpt/strategy/prompt_templates/game24.py