diff --git a/examples/stream_output_via_api.py b/examples/stream_output_via_api.py
index 94709b5bf..5961f3a08 100644
--- a/examples/stream_output_via_api.py
+++ b/examples/stream_output_via_api.py
@@ -6,20 +6,18 @@
 @File    : stream_output_via_api.py
 @Description    : Stream log information and communicate over the network via web api.
 """
+import asyncio
 import json
 import socket
-import asyncio
 import threading
-
 from contextvars import ContextVar
-from flask import Flask, Response
-from flask import request, jsonify, send_from_directory
 
-from metagpt.logs import logger
+from flask import Flask, Response, jsonify, request, send_from_directory
+
 from metagpt.const import TUTORIAL_PATH
-from metagpt.logs import set_llm_stream_logfunc
-from metagpt.utils.stream_pipe import StreamPipe
+from metagpt.logs import logger, set_llm_stream_logfunc
 from metagpt.roles.tutorial_assistant import TutorialAssistant
+from metagpt.utils.stream_pipe import StreamPipe
 
 app = Flask(__name__)
 
@@ -39,12 +37,18 @@ def write_tutorial(message):
 
     def thread_run(idea: str, stream_pipe: StreamPipe = None):
         """
-            Convert asynchronous function to thread function
+        Convert asynchronous function to thread function
         """
         asyncio.run(main(idea, stream_pipe))
 
     stream_pipe = StreamPipe()
-    thread = threading.Thread(target=thread_run, args=(message["content"], stream_pipe,))
+    thread = threading.Thread(
+        target=thread_run,
+        args=(
+            message["content"],
+            stream_pipe,
+        ),
+    )
     thread.start()
 
     while thread.is_alive():
@@ -52,7 +56,7 @@ def write_tutorial(message):
         yield stream_pipe.msg2stream(msg)
 
 
-@app.route('/v1/chat/completions', methods=['POST'])
+@app.route("/v1/chat/completions", methods=["POST"])
 def completions():
     """
     data: {
@@ -87,7 +91,7 @@ def completions():
         return jsonify({"status": 400, "msg": "No suitable agent found."})
 
 
-@app.route('/download/<path:filename>')
+@app.route("/download/<path:filename>")
 def download_file(filename):
     return send_from_directory(TUTORIAL_PATH, filename, as_attachment=True)
 
diff --git a/metagpt/provider/zhipuai_api.py b/metagpt/provider/zhipuai_api.py
index a45081fcf..acac44aaf 100644
--- a/metagpt/provider/zhipuai_api.py
+++ b/metagpt/provider/zhipuai_api.py
@@ -45,7 +45,13 @@ class ZhiPuAILLM(BaseLLM):
     def _const_kwargs(self, messages: list[dict], stream: bool = False) -> dict:
         max_tokens = self.config.max_token if self.config.max_token > 0 else 1024
         temperature = self.config.temperature if self.config.temperature > 0.0 else 0.3
-        kwargs = {"model": self.model, "max_tokens": max_tokens, "messages": messages, "stream": stream, "temperature": temperature}
+        kwargs = {
+            "model": self.model,
+            "max_tokens": max_tokens,
+            "messages": messages,
+            "stream": stream,
+            "temperature": temperature,
+        }
         return kwargs
 
     def completion(self, messages: list[dict], timeout=USE_CONFIG_TIMEOUT) -> dict:
diff --git a/metagpt/utils/stream_pipe.py b/metagpt/utils/stream_pipe.py
index d3d3cff32..4c4485158 100644
--- a/metagpt/utils/stream_pipe.py
+++ b/metagpt/utils/stream_pipe.py
@@ -5,8 +5,8 @@
 # @Version : None
 # @Description : None
 
-import time
 import json
+import time
 from multiprocessing import Pipe
 
 
@@ -21,17 +21,8 @@ class StreamPipe:
         "model": "gpt-3.5-turbo-0125",
         "system_fingerprint": "fp_3bc1b5746c",
         "choices": [
-            {
-                "index": 0,
-                "delta":
-                    {
-                        "role": "assistant",
-                        "content": "content"
-                    },
-                "logprobs": None,
-                "finish_reason": None
-            }
-        ]
+            {"index": 0, "delta": {"role": "assistant", "content": "content"}, "logprobs": None, "finish_reason": None}
+        ],
     }
 
     def set_message(self, msg):
@@ -44,6 +35,6 @@ class StreamPipe:
             return None
 
     def msg2stream(self, msg):
-        self.format_data['created'] = int(time.time())
-        self.format_data['choices'][0]['delta']['content'] = msg
+        self.format_data["created"] = int(time.time())
+        self.format_data["choices"][0]["delta"]["content"] = msg
         return f"data: {json.dumps(self.format_data, ensure_ascii=False)}\n".encode("utf-8")