diff --git a/.gitignore b/.gitignore
index 922116d12..aa5edd74a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,7 +1,7 @@
 ### Python template
 
 # Byte-compiled / optimized / DLL files
-__pycache__/
+__pycache__
 *.py[cod]
 *$py.class
 
diff --git a/examples/di/arxiv_reader.py b/examples/di/arxiv_reader.py
index fab0e2e48..6e1939b81 100644
--- a/examples/di/arxiv_reader.py
+++ b/examples/di/arxiv_reader.py
@@ -1,10 +1,5 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
-"""
-@Time    : 2024/01/15
-@Author  : mannaandpoem
-@File    : imitate_webpage.py
-"""
 from metagpt.roles.di.data_interpreter import DataInterpreter
 
 
diff --git a/examples/search_with_specific_engine.py b/examples/search_with_specific_engine.py
index 1eee762d5..276431ed8 100644
--- a/examples/search_with_specific_engine.py
+++ b/examples/search_with_specific_engine.py
@@ -13,7 +13,7 @@ async def main():
     question = "What are the most interesting human facts?"
 
     search = Config.default().search
-    kwargs = {"api_key": search.api_key, "cse_id": search.cse_id, "proxy": None}
+    kwargs = search.model_dump()
     await Searcher(search_engine=SearchEngine(engine=search.api_type, **kwargs)).run(question)
 
 
diff --git a/metagpt/actions/action_node.py b/metagpt/actions/action_node.py
index 3f822568e..27dde5a8c 100644
--- a/metagpt/actions/action_node.py
+++ b/metagpt/actions/action_node.py
@@ -331,7 +331,7 @@ class ActionNode:
 
     def compile_to(self, i: Dict, schema, kv_sep) -> str:
         if schema == "json":
-            return json.dumps(i, indent=4)
+            return json.dumps(i, indent=4, ensure_ascii=False)
         elif schema == "markdown":
             return dict_to_markdown(i, kv_sep=kv_sep)
         else:
diff --git a/metagpt/actions/di/write_analysis_code.py b/metagpt/actions/di/write_analysis_code.py
index 185926e31..711e56d39 100644
--- a/metagpt/actions/di/write_analysis_code.py
+++ b/metagpt/actions/di/write_analysis_code.py
@@ -18,7 +18,7 @@ from metagpt.prompts.di.write_analysis_code import (
     STRUCTUAL_PROMPT,
 )
 from metagpt.schema import Message, Plan
-from metagpt.utils.common import CodeParser, process_message, remove_comments
+from metagpt.utils.common import CodeParser, remove_comments
 
 
 class WriteAnalysisCode(Action):
@@ -50,7 +50,7 @@ class WriteAnalysisCode(Action):
         )
 
         working_memory = working_memory or []
-        context = process_message([Message(content=structual_prompt, role="user")] + working_memory)
+        context = self.llm.format_msg([Message(content=structual_prompt, role="user")] + working_memory)
 
         # LLM call
         if use_reflection:
diff --git a/metagpt/configs/search_config.py b/metagpt/configs/search_config.py
index af928b02a..e28b14c99 100644
--- a/metagpt/configs/search_config.py
+++ b/metagpt/configs/search_config.py
@@ -7,6 +7,8 @@
 """
 from typing import Callable, Optional
 
+from pydantic import Field
+
 from metagpt.tools import SearchEngineType
 from metagpt.utils.yaml_model import YamlModel
 
@@ -18,3 +20,11 @@ class SearchConfig(YamlModel):
     api_key: str = ""
     cse_id: str = ""  # for google
     search_func: Optional[Callable] = None
+    params: dict = Field(
+        default_factory=lambda: {
+            "engine": "google",
+            "google_domain": "google.com",
+            "gl": "us",
+            "hl": "en",
+        }
+    )
diff --git a/metagpt/learn/skill_loader.py b/metagpt/learn/skill_loader.py
index bcf28bb87..e98f73cf9 100644
--- a/metagpt/learn/skill_loader.py
+++ b/metagpt/learn/skill_loader.py
@@ -9,11 +9,11 @@
 from pathlib import Path
 from typing import Dict, List, Optional
 
-import aiofiles
 import yaml
 from pydantic import BaseModel, Field
 
 from metagpt.context import Context
+from metagpt.utils.common import aread
 
 
 class Example(BaseModel):
@@ -68,8 +68,7 @@ class SkillsDeclaration(BaseModel):
     async def load(skill_yaml_file_name: Path = None) -> "SkillsDeclaration":
         if not skill_yaml_file_name:
             skill_yaml_file_name = Path(__file__).parent.parent.parent / "docs/.well-known/skills.yaml"
-        async with aiofiles.open(str(skill_yaml_file_name), mode="r") as reader:
-            data = await reader.read(-1)
+        data = await aread(filename=skill_yaml_file_name)
         skill_data = yaml.safe_load(data)
         return SkillsDeclaration(**skill_data)
 
diff --git a/metagpt/provider/base_llm.py b/metagpt/provider/base_llm.py
index e085d0187..db2757ec3 100644
--- a/metagpt/provider/base_llm.py
+++ b/metagpt/provider/base_llm.py
@@ -74,6 +74,28 @@ class BaseLLM(ABC):
     def _system_msg(self, msg: str) -> dict[str, str]:
         return {"role": "system", "content": msg}
 
+    def format_msg(self, messages: Union[str, Message, list[dict], list[Message], list[str]]) -> list[dict]:
+        """convert messages to list[dict]."""
+        from metagpt.schema import Message
+
+        if not isinstance(messages, list):
+            messages = [messages]
+
+        processed_messages = []
+        for msg in messages:
+            if isinstance(msg, str):
+                processed_messages.append({"role": "user", "content": msg})
+            elif isinstance(msg, dict):
+                assert set(msg.keys()) == set(["role", "content"])
+                processed_messages.append(msg)
+            elif isinstance(msg, Message):
+                processed_messages.append(msg.to_dict())
+            else:
+                raise ValueError(
+                    f"Only support message type are: str, Message, dict, but got {type(messages).__name__}!"
+                )
+        return processed_messages
+
     def _system_msgs(self, msgs: list[str]) -> list[dict[str, str]]:
         return [self._system_msg(msg) for msg in msgs]
 
diff --git a/metagpt/provider/google_gemini_api.py b/metagpt/provider/google_gemini_api.py
index e041f4c87..7a35f0a9d 100644
--- a/metagpt/provider/google_gemini_api.py
+++ b/metagpt/provider/google_gemini_api.py
@@ -2,6 +2,7 @@
 # -*- coding: utf-8 -*-
 # @Desc   : Google Gemini LLM from https://ai.google.dev/tutorials/python_quickstart
 
+import os
 from typing import Optional, Union
 
 import google.generativeai as genai
@@ -16,9 +17,10 @@ from google.generativeai.types.generation_types import (
 
 from metagpt.configs.llm_config import LLMConfig, LLMType
 from metagpt.const import USE_CONFIG_TIMEOUT
-from metagpt.logs import log_llm_stream
+from metagpt.logs import log_llm_stream, logger
 from metagpt.provider.base_llm import BaseLLM
 from metagpt.provider.llm_provider_registry import register_provider
+from metagpt.schema import Message
 
 
 class GeminiGenerativeModel(GenerativeModel):
@@ -52,6 +54,10 @@ class GeminiLLM(BaseLLM):
         self.llm = GeminiGenerativeModel(model_name=self.model)
 
     def __init_gemini(self, config: LLMConfig):
+        if config.proxy:
+            logger.info(f"Use proxy: {config.proxy}")
+            os.environ["HTTP_PROXY"] = config.proxy
+            os.environ["HTTP_PROXYS"] = config.proxy
         genai.configure(api_key=config.api_key)
 
     def _user_msg(self, msg: str, images: Optional[Union[str, list[str]]] = None) -> dict[str, str]:
@@ -62,6 +68,35 @@ class GeminiLLM(BaseLLM):
     def _assistant_msg(self, msg: str) -> dict[str, str]:
         return {"role": "model", "parts": [msg]}
 
+    def _system_msg(self, msg: str) -> dict[str, str]:
+        return {"role": "user", "parts": [msg]}
+
+    def format_msg(self, messages: Union[str, Message, list[dict], list[Message], list[str]]) -> list[dict]:
+        """convert messages to list[dict]."""
+        from metagpt.schema import Message
+
+        if not isinstance(messages, list):
+            messages = [messages]
+
+        # REF: https://ai.google.dev/tutorials/python_quickstart
+        # As a dictionary, the message requires `role` and `parts` keys.
+        # The role in a conversation can either be the `user`, which provides the prompts,
+        # or `model`, which provides the responses.
+        processed_messages = []
+        for msg in messages:
+            if isinstance(msg, str):
+                processed_messages.append({"role": "user", "parts": [msg]})
+            elif isinstance(msg, dict):
+                assert set(msg.keys()) == set(["role", "parts"])
+                processed_messages.append(msg)
+            elif isinstance(msg, Message):
+                processed_messages.append({"role": "user" if msg.role == "user" else "model", "parts": [msg.content]})
+            else:
+                raise ValueError(
+                    f"Only support message type are: str, Message, dict, but got {type(messages).__name__}!"
+                )
+        return processed_messages
+
     def _const_kwargs(self, messages: list[dict], stream: bool = False) -> dict:
         kwargs = {"contents": messages, "generation_config": GenerationConfig(temperature=0.3), "stream": stream}
         return kwargs
diff --git a/metagpt/provider/openai_api.py b/metagpt/provider/openai_api.py
index 10b7749d6..dbfed72df 100644
--- a/metagpt/provider/openai_api.py
+++ b/metagpt/provider/openai_api.py
@@ -30,12 +30,7 @@ from metagpt.logs import log_llm_stream, logger
 from metagpt.provider.base_llm import BaseLLM
 from metagpt.provider.constant import GENERAL_FUNCTION_SCHEMA
 from metagpt.provider.llm_provider_registry import register_provider
-from metagpt.utils.common import (
-    CodeParser,
-    decode_image,
-    log_and_reraise,
-    process_message,
-)
+from metagpt.utils.common import CodeParser, decode_image, log_and_reraise
 from metagpt.utils.cost_manager import CostManager
 from metagpt.utils.exceptions import handle_exception
 from metagpt.utils.token_counter import (
@@ -151,7 +146,7 @@ class OpenAILLM(BaseLLM):
     async def _achat_completion_function(
         self, messages: list[dict], timeout: int = USE_CONFIG_TIMEOUT, **chat_configs
     ) -> ChatCompletion:
-        messages = process_message(messages)
+        messages = self.format_msg(messages)
         kwargs = self._cons_kwargs(messages=messages, timeout=self.get_timeout(timeout), **chat_configs)
         rsp: ChatCompletion = await self.aclient.chat.completions.create(**kwargs)
         self._update_costs(rsp.usage)
diff --git a/metagpt/utils/common.py b/metagpt/utils/common.py
index e9cef69a4..c8daba724 100644
--- a/metagpt/utils/common.py
+++ b/metagpt/utils/common.py
@@ -29,6 +29,7 @@ from typing import Any, Callable, List, Literal, Tuple, Union
 from urllib.parse import quote, unquote
 
 import aiofiles
+import chardet
 import loguru
 import requests
 from PIL import Image
@@ -663,14 +664,21 @@ def role_raise_decorator(func):
 
 
 @handle_exception
-async def aread(filename: str | Path, encoding=None) -> str:
+async def aread(filename: str | Path, encoding="utf-8") -> str:
     """Read file asynchronously."""
-    async with aiofiles.open(str(filename), mode="r", encoding=encoding) as reader:
-        content = await reader.read()
+    try:
+        async with aiofiles.open(str(filename), mode="r", encoding=encoding) as reader:
+            content = await reader.read()
+    except UnicodeDecodeError:
+        async with aiofiles.open(str(filename), mode="rb") as reader:
+            raw = await reader.read()
+            result = chardet.detect(raw)
+            detected_encoding = result["encoding"]
+            content = raw.decode(detected_encoding)
     return content
 
 
-async def awrite(filename: str | Path, data: str, encoding=None):
+async def awrite(filename: str | Path, data: str, encoding="utf-8"):
     """Write file asynchronously."""
     pathname = Path(filename)
     pathname.parent.mkdir(parents=True, exist_ok=True)
@@ -802,29 +810,6 @@ def decode_image(img_url_or_b64: str) -> Image:
     return img
 
 
-def process_message(messages: Union[str, Message, list[dict], list[Message], list[str]]) -> list[dict]:
-    """convert messages to list[dict]."""
-    from metagpt.schema import Message
-
-    # 全部转成list
-    if not isinstance(messages, list):
-        messages = [messages]
-
-    # 转成list[dict]
-    processed_messages = []
-    for msg in messages:
-        if isinstance(msg, str):
-            processed_messages.append({"role": "user", "content": msg})
-        elif isinstance(msg, dict):
-            assert set(msg.keys()) == set(["role", "content"])
-            processed_messages.append(msg)
-        elif isinstance(msg, Message):
-            processed_messages.append(msg.to_dict())
-        else:
-            raise ValueError(f"Only support message type are: str, Message, dict, but got {type(messages).__name__}!")
-    return processed_messages
-
-
 def log_and_reraise(retry_state: RetryCallState):
     logger.error(f"Retry attempts exhausted. Last exception: {retry_state.outcome.exception()}")
     logger.warning(
diff --git a/metagpt/utils/dependency_file.py b/metagpt/utils/dependency_file.py
index d3add1171..0a375051c 100644
--- a/metagpt/utils/dependency_file.py
+++ b/metagpt/utils/dependency_file.py
@@ -13,9 +13,7 @@ import re
 from pathlib import Path
 from typing import Set
 
-import aiofiles
-
-from metagpt.utils.common import aread
+from metagpt.utils.common import aread, awrite
 from metagpt.utils.exceptions import handle_exception
 
 
@@ -45,8 +43,7 @@ class DependencyFile:
     async def save(self):
         """Save dependencies to the file asynchronously."""
         data = json.dumps(self._dependencies)
-        async with aiofiles.open(str(self._filename), mode="w") as writer:
-            await writer.write(data)
+        await awrite(filename=self._filename, data=data)
 
     async def update(self, filename: Path | str, dependencies: Set[Path | str], persist=True):
         """Update dependencies for a file asynchronously.
diff --git a/metagpt/utils/file_repository.py b/metagpt/utils/file_repository.py
index d2a06963a..d19f2b705 100644
--- a/metagpt/utils/file_repository.py
+++ b/metagpt/utils/file_repository.py
@@ -14,11 +14,9 @@ from datetime import datetime
 from pathlib import Path
 from typing import Dict, List, Set
 
-import aiofiles
-
 from metagpt.logs import logger
 from metagpt.schema import Document
-from metagpt.utils.common import aread
+from metagpt.utils.common import aread, awrite
 from metagpt.utils.json_to_markdown import json_to_markdown
 
 
@@ -55,8 +53,7 @@ class FileRepository:
         pathname = self.workdir / filename
         pathname.parent.mkdir(parents=True, exist_ok=True)
         content = content if content else ""  # avoid `argument must be str, not None` to make it continue
-        async with aiofiles.open(str(pathname), mode="w") as writer:
-            await writer.write(content)
+        await awrite(filename=str(pathname), data=content)
         logger.info(f"save to: {str(pathname)}")
 
         if dependencies is not None:
diff --git a/metagpt/utils/mermaid.py b/metagpt/utils/mermaid.py
index ae3c5118f..e1d140e84 100644
--- a/metagpt/utils/mermaid.py
+++ b/metagpt/utils/mermaid.py
@@ -9,11 +9,9 @@ import asyncio
 import os
 from pathlib import Path
 
-import aiofiles
-
 from metagpt.config2 import config
 from metagpt.logs import logger
-from metagpt.utils.common import check_cmd_exists
+from metagpt.utils.common import awrite, check_cmd_exists
 
 
 async def mermaid_to_file(engine, mermaid_code, output_file_without_suffix, width=2048, height=2048) -> int:
@@ -30,9 +28,7 @@ async def mermaid_to_file(engine, mermaid_code, output_file_without_suffix, widt
     if dir_name and not os.path.exists(dir_name):
         os.makedirs(dir_name)
     tmp = Path(f"{output_file_without_suffix}.mmd")
-    async with aiofiles.open(tmp, "w", encoding="utf-8") as f:
-        await f.write(mermaid_code)
-    # tmp.write_text(mermaid_code, encoding="utf-8")
+    await awrite(filename=tmp, data=mermaid_code)
 
     if engine == "nodejs":
         if check_cmd_exists(config.mermaid.path) != 0:
diff --git a/metagpt/utils/repair_llm_raw_output.py b/metagpt/utils/repair_llm_raw_output.py
index b8756e8c6..17e095c5f 100644
--- a/metagpt/utils/repair_llm_raw_output.py
+++ b/metagpt/utils/repair_llm_raw_output.py
@@ -340,7 +340,9 @@ def extract_state_value_from_output(content: str) -> str:
         content (str): llm's output from `Role._think`
     """
     content = content.strip()  # deal the output cases like " 0", "0\n" and so on.
-    pattern = r"([0-9])"  # TODO find the number using a more proper method not just extract from content using pattern
+    pattern = (
+        r"(?<!-)[0-9]"  # TODO find the number using a more proper method not just extract from content using pattern
+    )
     matches = re.findall(pattern, content, re.DOTALL)
     matches = list(set(matches))
     state = matches[0] if len(matches) > 0 else "-1"
diff --git a/metagpt/utils/tree.py b/metagpt/utils/tree.py
new file mode 100644
index 000000000..bd7922290
--- /dev/null
+++ b/metagpt/utils/tree.py
@@ -0,0 +1,140 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+"""
+@Time    : 2024/3/11
+@Author  : mashenquan
+@File    : tree.py
+@Desc    : Implement the same functionality as the `tree` command.
+        Example:
+            >>> print_tree(".")
+            utils
+            +-- serialize.py
+            +-- project_repo.py
+            +-- tree.py
+            +-- mmdc_playwright.py
+            +-- cost_manager.py
+            +-- __pycache__
+            |   +-- __init__.cpython-39.pyc
+            |   +-- redis.cpython-39.pyc
+            |   +-- singleton.cpython-39.pyc
+            |   +-- embedding.cpython-39.pyc
+            |   +-- make_sk_kernel.cpython-39.pyc
+            |   +-- file_repository.cpython-39.pyc
+            +-- file.py
+            +-- save_code.py
+            +-- common.py
+            +-- redis.py
+"""
+from __future__ import annotations
+
+import subprocess
+from pathlib import Path
+from typing import Callable, Dict, List
+
+from gitignore_parser import parse_gitignore
+
+
+def tree(root: str | Path, gitignore: str | Path = None, run_command: bool = False) -> str:
+    """
+    Recursively traverses the directory structure and prints it out in a tree-like format.
+
+    Args:
+        root (str or Path): The root directory from which to start traversing.
+        gitignore (str or Path): The filename of gitignore file.
+        run_command (bool): Whether to execute `tree` command. Execute the `tree` command and return the result if True,
+            otherwise execute python code instead.
+
+    Returns:
+        str: A string representation of the directory tree.
+
+    Example:
+            >>> tree(".")
+            utils
+            +-- serialize.py
+            +-- project_repo.py
+            +-- tree.py
+            +-- mmdc_playwright.py
+            +-- __pycache__
+            |   +-- __init__.cpython-39.pyc
+            |   +-- redis.cpython-39.pyc
+            |   +-- singleton.cpython-39.pyc
+            +-- parse_docstring.py
+
+            >>> tree(".", gitignore="../../.gitignore")
+            utils
+            +-- serialize.py
+            +-- project_repo.py
+            +-- tree.py
+            +-- mmdc_playwright.py
+            +-- parse_docstring.py
+
+            >>> tree(".", gitignore="../../.gitignore", run_command=True)
+            utils
+            ├── serialize.py
+            ├── project_repo.py
+            ├── tree.py
+            ├── mmdc_playwright.py
+            └── parse_docstring.py
+
+
+    """
+    root = Path(root).resolve()
+    if run_command:
+        return _execute_tree(root, gitignore)
+
+    git_ignore_rules = parse_gitignore(gitignore) if gitignore else None
+    dir_ = {root.name: _list_children(root=root, git_ignore_rules=git_ignore_rules)}
+    v = _print_tree(dir_)
+    return "\n".join(v)
+
+
+def _list_children(root: Path, git_ignore_rules: Callable) -> Dict[str, Dict]:
+    dir_ = {}
+    for i in root.iterdir():
+        if git_ignore_rules and git_ignore_rules(str(i)):
+            continue
+        try:
+            if i.is_file():
+                dir_[i.name] = {}
+            else:
+                dir_[i.name] = _list_children(root=i, git_ignore_rules=git_ignore_rules)
+        except (FileNotFoundError, PermissionError, OSError):
+            dir_[i.name] = {}
+    return dir_
+
+
+def _print_tree(dir_: Dict[str:Dict]) -> List[str]:
+    ret = []
+    for name, children in dir_.items():
+        ret.append(name)
+        if not children:
+            continue
+        lines = _print_tree(children)
+        for j, v in enumerate(lines):
+            if v[0] not in ["+", " ", "|"]:
+                ret = _add_line(ret)
+                row = f"+-- {v}"
+            else:
+                row = f"    {v}"
+            ret.append(row)
+    return ret
+
+
+def _add_line(rows: List[str]) -> List[str]:
+    for i in range(len(rows) - 1, -1, -1):
+        v = rows[i]
+        if v[0] != " ":
+            return rows
+        rows[i] = "|" + v[1:]
+    return rows
+
+
+def _execute_tree(root: Path, gitignore: str | Path) -> str:
+    args = ["--gitfile", str(gitignore)] if gitignore else []
+    try:
+        result = subprocess.run(["tree"] + args + [str(root)], capture_output=True, text=True, check=True)
+        if result.returncode != 0:
+            raise ValueError(f"tree exits with code {result.returncode}")
+        return result.stdout
+    except subprocess.CalledProcessError as e:
+        raise e
diff --git a/setup.py b/setup.py
index 7a14c6182..df9bedc9b 100644
--- a/setup.py
+++ b/setup.py
@@ -57,7 +57,7 @@ extras_require["dev"] = (["pylint~=3.0.3", "black~=23.3.0", "isort~=5.12.0", "pr
 
 setup(
     name="metagpt",
-    version="0.7.4",
+    version="0.7.6",
     description="The Multi-Agent Framework",
     long_description=long_description,
     long_description_content_type="text/markdown",
diff --git a/tests/metagpt/roles/test_tutorial_assistant.py b/tests/metagpt/roles/test_tutorial_assistant.py
index c12c2b26e..732f346fd 100644
--- a/tests/metagpt/roles/test_tutorial_assistant.py
+++ b/tests/metagpt/roles/test_tutorial_assistant.py
@@ -6,11 +6,11 @@
 @File    : test_tutorial_assistant.py
 """
 
-import aiofiles
 import pytest
 
 from metagpt.const import TUTORIAL_PATH
 from metagpt.roles.tutorial_assistant import TutorialAssistant
+from metagpt.utils.common import aread
 
 
 @pytest.mark.asyncio
@@ -20,9 +20,8 @@ async def test_tutorial_assistant(language: str, topic: str, context):
     msg = await role.run(topic)
     assert TUTORIAL_PATH.exists()
     filename = msg.content
-    async with aiofiles.open(filename, mode="r", encoding="utf-8") as reader:
-        content = await reader.read()
-        assert "pip" in content
+    content = await aread(filename=filename)
+    assert "pip" in content
 
 
 if __name__ == "__main__":
diff --git a/tests/metagpt/tools/test_search_engine.py b/tests/metagpt/tools/test_search_engine.py
index a1f03ef7b..964ead02f 100644
--- a/tests/metagpt/tools/test_search_engine.py
+++ b/tests/metagpt/tools/test_search_engine.py
@@ -11,7 +11,6 @@ from typing import Callable
 
 import pytest
 
-from metagpt.config2 import config
 from metagpt.configs.search_config import SearchConfig
 from metagpt.logs import logger
 from metagpt.tools import SearchEngineType
@@ -53,14 +52,11 @@ async def test_search_engine(
     search_engine_config = {"engine": search_engine_type, "run_func": run_func}
 
     if search_engine_type is SearchEngineType.SERPAPI_GOOGLE:
-        assert config.search
         search_engine_config["api_key"] = "mock-serpapi-key"
     elif search_engine_type is SearchEngineType.DIRECT_GOOGLE:
-        assert config.search
         search_engine_config["api_key"] = "mock-google-key"
         search_engine_config["cse_id"] = "mock-google-cse"
     elif search_engine_type is SearchEngineType.SERPER_GOOGLE:
-        assert config.search
         search_engine_config["api_key"] = "mock-serper-key"
 
     async def test(search_engine):
diff --git a/tests/metagpt/utils/test_common.py b/tests/metagpt/utils/test_common.py
index b365f424f..75e8ef4ad 100644
--- a/tests/metagpt/utils/test_common.py
+++ b/tests/metagpt/utils/test_common.py
@@ -13,7 +13,6 @@ import uuid
 from pathlib import Path
 from typing import Any, Set
 
-import aiofiles
 import pytest
 from pydantic import BaseModel
 
@@ -125,9 +124,7 @@ class TestGetProjectRoot:
     async def test_parse_data_exception(self, filename, want):
         pathname = Path(__file__).parent.parent.parent / "data/output_parser" / filename
         assert pathname.exists()
-        async with aiofiles.open(str(pathname), mode="r") as reader:
-            data = await reader.read()
-
+        data = await aread(filename=pathname)
         result = OutputParser.parse_data(data=data)
         assert want in result
 
@@ -198,12 +195,25 @@ class TestGetProjectRoot:
 
     @pytest.mark.asyncio
     async def test_read_write(self):
-        pathname = Path(__file__).parent / uuid.uuid4().hex / "test.tmp"
+        pathname = Path(__file__).parent / f"../../../workspace/unittest/{uuid.uuid4().hex}" / "test.tmp"
         await awrite(pathname, "ABC")
         data = await aread(pathname)
         assert data == "ABC"
         pathname.unlink(missing_ok=True)
 
+    @pytest.mark.asyncio
+    async def test_read_write_error_charset(self):
+        pathname = Path(__file__).parent / f"../../../workspace/unittest/{uuid.uuid4().hex}" / "test.txt"
+        content = "中国abc123\u27f6"
+        await awrite(filename=pathname, data=content)
+        data = await aread(filename=pathname)
+        assert data == content
+
+        content = "GB18030 是中国国家标准局发布的新一代中文字符集标准，是 GBK 的升级版，支持更广泛的字符范围。"
+        await awrite(filename=pathname, data=content, encoding="gb2312")
+        data = await aread(filename=pathname, encoding="utf-8")
+        assert data == content
+
 
 if __name__ == "__main__":
     pytest.main([__file__, "-s"])
diff --git a/tests/metagpt/utils/test_git_repository.py b/tests/metagpt/utils/test_git_repository.py
index ea28b8f0b..480a22e24 100644
--- a/tests/metagpt/utils/test_git_repository.py
+++ b/tests/metagpt/utils/test_git_repository.py
@@ -10,15 +10,14 @@
 import shutil
 from pathlib import Path
 
-import aiofiles
 import pytest
 
+from metagpt.utils.common import awrite
 from metagpt.utils.git_repository import GitRepository
 
 
 async def mock_file(filename, content=""):
-    async with aiofiles.open(str(filename), mode="w") as file:
-        await file.write(content)
+    await awrite(filename=filename, data=content)
 
 
 async def mock_repo(local_path) -> (GitRepository, Path):
diff --git a/tests/metagpt/utils/test_s3.py b/tests/metagpt/utils/test_s3.py
index 34c21612c..ef13c2325 100644
--- a/tests/metagpt/utils/test_s3.py
+++ b/tests/metagpt/utils/test_s3.py
@@ -9,7 +9,6 @@ import uuid
 from pathlib import Path
 
 import aioboto3
-import aiofiles
 import pytest
 
 from metagpt.config2 import Config
@@ -46,7 +45,7 @@ async def test_s3(mocker):
     conn = S3(s3)
     object_name = "unittest.bak"
     await conn.upload_file(bucket=s3.bucket, local_path=__file__, object_name=object_name)
-    pathname = (Path(__file__).parent / uuid.uuid4().hex).with_suffix(".bak")
+    pathname = (Path(__file__).parent / "../../../workspace/unittest" / uuid.uuid4().hex).with_suffix(".bak")
     pathname.unlink(missing_ok=True)
     await conn.download_file(bucket=s3.bucket, object_name=object_name, local_path=str(pathname))
     assert pathname.exists()
@@ -54,8 +53,7 @@ async def test_s3(mocker):
     assert url
     bin_data = await conn.get_object(bucket=s3.bucket, object_name=object_name)
     assert bin_data
-    async with aiofiles.open(__file__, mode="r", encoding="utf-8") as reader:
-        data = await reader.read()
+    data = await aread(filename=__file__)
     res = await conn.cache(data, ".bak", "script")
     assert "http" in res
 
@@ -69,8 +67,6 @@ async def test_s3(mocker):
     except Exception:
         pass
 
-    await reader.close()
-
 
 if __name__ == "__main__":
     pytest.main([__file__, "-s"])
diff --git a/tests/metagpt/utils/test_tree.py b/tests/metagpt/utils/test_tree.py
new file mode 100644
index 000000000..03a2a5606
--- /dev/null
+++ b/tests/metagpt/utils/test_tree.py
@@ -0,0 +1,64 @@
+from pathlib import Path
+from typing import List
+
+import pytest
+
+from metagpt.utils.tree import _print_tree, tree
+
+
+@pytest.mark.parametrize(
+    ("root", "rules"),
+    [
+        (str(Path(__file__).parent / "../.."), None),
+        (str(Path(__file__).parent / "../.."), str(Path(__file__).parent / "../../../.gitignore")),
+    ],
+)
+def test_tree(root: str, rules: str):
+    v = tree(root=root, gitignore=rules)
+    assert v
+
+
+@pytest.mark.parametrize(
+    ("root", "rules"),
+    [
+        (str(Path(__file__).parent / "../.."), None),
+        (str(Path(__file__).parent / "../.."), str(Path(__file__).parent / "../../../.gitignore")),
+    ],
+)
+def test_tree_command(root: str, rules: str):
+    v = tree(root=root, gitignore=rules, run_command=True)
+    assert v
+
+
+@pytest.mark.parametrize(
+    ("tree", "want"),
+    [
+        ({"a": {"b": {}, "c": {}}}, ["a", "+-- b", "+-- c"]),
+        ({"a": {"b": {}, "c": {"d": {}}}}, ["a", "+-- b", "+-- c", "    +-- d"]),
+        (
+            {"a": {"b": {"e": {"f": {}, "g": {}}}, "c": {"d": {}}}},
+            ["a", "+-- b", "|   +-- e", "|       +-- f", "|       +-- g", "+-- c", "    +-- d"],
+        ),
+        (
+            {"h": {"a": {"b": {"e": {"f": {}, "g": {}}}, "c": {"d": {}}}, "i": {}}},
+            [
+                "h",
+                "+-- a",
+                "|   +-- b",
+                "|   |   +-- e",
+                "|   |       +-- f",
+                "|   |       +-- g",
+                "|   +-- c",
+                "|       +-- d",
+                "+-- i",
+            ],
+        ),
+    ],
+)
+def test__print_tree(tree: dict, want: List[str]):
+    v = _print_tree(tree)
+    assert v == want
+
+
+if __name__ == "__main__":
+    pytest.main([__file__, "-s"])
diff --git a/tests/mock/mock_llm.py b/tests/mock/mock_llm.py
index b4cdfa0cf..c4262e080 100644
--- a/tests/mock/mock_llm.py
+++ b/tests/mock/mock_llm.py
@@ -8,7 +8,6 @@ from metagpt.provider.azure_openai_api import AzureOpenAILLM
 from metagpt.provider.constant import GENERAL_FUNCTION_SCHEMA
 from metagpt.provider.openai_api import OpenAILLM
 from metagpt.schema import Message
-from metagpt.utils.common import process_message
 
 OriginalLLM = OpenAILLM if config.llm.api_type == LLMType.OPENAI else AzureOpenAILLM
 
@@ -105,7 +104,7 @@ class MockLLM(OriginalLLM):
         return rsp
 
     async def aask_code(self, messages: Union[str, Message, list[dict]], **kwargs) -> dict:
-        msg_key = json.dumps(process_message(messages), ensure_ascii=False)
+        msg_key = json.dumps(self.format_msg(messages), ensure_ascii=False)
         rsp = await self._mock_rsp(msg_key, self.original_aask_code, messages, **kwargs)
         return rsp