diff --git a/config/config.yaml b/config/config.yaml
index ab4d49f5d..5025a4977 100644
--- a/config/config.yaml
+++ b/config/config.yaml
@@ -141,3 +141,4 @@ TIMEOUT: 60 # Timeout for llm invocation
 #REDIS_PASSWORD: "YOUR_REDIS_PASSWORD"
 #REDIS_DB: "YOUR_REDIS_DB_INDEX, str, 0-based"
 
+# DISABLE_LLM_PROVIDER_CHECK: false
diff --git a/metagpt/actions/research.py b/metagpt/actions/research.py
index 074cdee0a..c47a77bdd 100644
--- a/metagpt/actions/research.py
+++ b/metagpt/actions/research.py
@@ -180,9 +180,11 @@ class WebBrowseAndSummarize(Action):
     llm: BaseGPTAPI = Field(default_factory=LLM)
     desc: str = "Explore the web and provide summaries of articles and webpages."
     browse_func: Union[Callable[[list[str]], None], None] = None
-    web_browser_engine: WebBrowserEngine = WebBrowserEngine(
-        engine=WebBrowserEngineType.CUSTOM if browse_func else None,
-        run_func=browse_func,
+    web_browser_engine: WebBrowserEngine = Field(
+        default_factory=lambda: WebBrowserEngine(
+            engine=WebBrowserEngineType.CUSTOM if WebBrowseAndSummarize.browse_func else None,
+            run_func=WebBrowseAndSummarize.browse_func,
+        )
     )
 
     def __init__(self, **kwargs):
diff --git a/metagpt/config.py b/metagpt/config.py
index 222254ac7..1ce12216d 100644
--- a/metagpt/config.py
+++ b/metagpt/config.py
@@ -138,7 +138,9 @@ class Config(metaclass=Singleton):
         self.gemini_api_key = self._get("GEMINI_API_KEY")
         self.ollama_api_base = self._get("OLLAMA_API_BASE")
         self.ollama_api_model = self._get("OLLAMA_API_MODEL")
-        # _ = self.get_default_llm_provider_enum()
+
+        if not self._get("DISABLE_LLM_PROVIDER_CHECK"):
+            _ = self.get_default_llm_provider_enum()
 
         # self.openai_base_url = self._get("OPENAI_BASE_URL")
         self.openai_proxy = self._get("OPENAI_PROXY") or self.global_proxy
diff --git a/metagpt/llm.py b/metagpt/llm.py
index 8763642f0..f1cb98dae 100644
--- a/metagpt/llm.py
+++ b/metagpt/llm.py
@@ -6,6 +6,8 @@
 @File    : llm.py
 """
 
+from typing import Optional
+
 from metagpt.config import CONFIG, LLMProviderEnum
 from metagpt.provider.base_gpt_api import BaseGPTAPI
 from metagpt.provider.human_provider import HumanProvider
@@ -14,6 +16,9 @@ from metagpt.provider.llm_provider_registry import LLM_REGISTRY
 _ = HumanProvider()  # Avoid pre-commit error
 
 
-def LLM(provider: LLMProviderEnum = CONFIG.get_default_llm_provider_enum()) -> BaseGPTAPI:
+def LLM(provider: Optional[LLMProviderEnum] = None) -> BaseGPTAPI:
     """get the default llm provider"""
+    if provider is None:
+        provider = CONFIG.get_default_llm_provider_enum()
+
     return LLM_REGISTRY.get_provider(provider)
diff --git a/metagpt/logs.py b/metagpt/logs.py
index ab1bc4e94..fb0fdd553 100644
--- a/metagpt/logs.py
+++ b/metagpt/logs.py
@@ -8,6 +8,7 @@
 
 import sys
 from datetime import datetime
+from functools import partial
 
 from loguru import logger as _logger
 
@@ -26,3 +27,15 @@ def define_log_level(print_level="INFO", logfile_level="DEBUG"):
 
 
 logger = define_log_level()
+
+
+def log_llm_stream(msg):
+    _llm_stream_log(msg)
+
+
+def set_llm_stream_logfunc(func):
+    global _llm_stream_log
+    _llm_stream_log = func
+
+
+_llm_stream_log = partial(print, end="")
diff --git a/metagpt/provider/google_gemini_api.py b/metagpt/provider/google_gemini_api.py
index e9d3ea70d..eace329aa 100644
--- a/metagpt/provider/google_gemini_api.py
+++ b/metagpt/provider/google_gemini_api.py
@@ -20,7 +20,7 @@ from tenacity import (
 )
 
 from metagpt.config import CONFIG, LLMProviderEnum
-from metagpt.logs import logger
+from metagpt.logs import log_llm_stream, logger
 from metagpt.provider.base_gpt_api import BaseGPTAPI
 from metagpt.provider.llm_provider_registry import register_provider
 from metagpt.provider.openai_api import log_and_reraise
@@ -121,7 +121,7 @@ class GeminiGPTAPI(BaseGPTAPI):
         collected_content = []
         async for chunk in resp:
             content = chunk.text
-            print(content, end="")
+            log_llm_stream(content)
             collected_content.append(content)
 
         full_content = "".join(collected_content)
diff --git a/metagpt/provider/ollama_api.py b/metagpt/provider/ollama_api.py
index 7d858e769..90a50a154 100644
--- a/metagpt/provider/ollama_api.py
+++ b/metagpt/provider/ollama_api.py
@@ -15,7 +15,7 @@ from tenacity import (
 
 from metagpt.config import CONFIG, LLMProviderEnum
 from metagpt.const import LLM_API_TIMEOUT
-from metagpt.logs import logger
+from metagpt.logs import log_llm_stream, logger
 from metagpt.provider.base_gpt_api import BaseGPTAPI
 from metagpt.provider.general_api_requestor import GeneralAPIRequestor
 from metagpt.provider.llm_provider_registry import register_provider
@@ -131,7 +131,7 @@ class OllamaGPTAPI(BaseGPTAPI):
             if not chunk.get("done", False):
                 content = self.get_choice_text(chunk)
                 collected_content.append(content)
-                print(content, end="")
+                log_llm_stream(content)
             else:
                 # stream finished
                 usage = self.get_usage(chunk)
diff --git a/metagpt/provider/openai_api.py b/metagpt/provider/openai_api.py
index 1d2cdb591..195d2ea16 100644
--- a/metagpt/provider/openai_api.py
+++ b/metagpt/provider/openai_api.py
@@ -29,7 +29,7 @@ from tenacity import (
 
 from metagpt.config import CONFIG, Config, LLMProviderEnum
 from metagpt.const import DEFAULT_MAX_TOKENS, DEFAULT_TOKEN_SIZE
-from metagpt.logs import logger
+from metagpt.logs import log_llm_stream, logger
 from metagpt.provider.base_gpt_api import BaseGPTAPI
 from metagpt.provider.constant import GENERAL_FUNCTION_SCHEMA, GENERAL_TOOL_CHOICE
 from metagpt.provider.llm_provider_registry import register_provider
@@ -180,7 +180,7 @@ class OpenAIGPTAPI(BaseGPTAPI, RateLimiter):
 
             collected_messages = []
             async for i in resp:
-                print(i, end="")
+                log_llm_stream(i)
                 collected_messages.append(i)
 
             full_reply_content = "".join(collected_messages)
diff --git a/metagpt/provider/zhipuai_api.py b/metagpt/provider/zhipuai_api.py
index 0d5663431..8d57cd444 100644
--- a/metagpt/provider/zhipuai_api.py
+++ b/metagpt/provider/zhipuai_api.py
@@ -16,7 +16,7 @@ from tenacity import (
 )
 
 from metagpt.config import CONFIG, LLMProviderEnum
-from metagpt.logs import logger
+from metagpt.logs import log_llm_stream, logger
 from metagpt.provider.base_gpt_api import BaseGPTAPI
 from metagpt.provider.llm_provider_registry import register_provider
 from metagpt.provider.openai_api import log_and_reraise
@@ -96,7 +96,7 @@ class ZhiPuAIGPTAPI(BaseGPTAPI):
             if event.event == ZhiPuEvent.ADD.value:
                 content = event.data
                 collected_content.append(content)
-                print(content, end="")
+                log_llm_stream(content)
             elif event.event == ZhiPuEvent.ERROR.value or event.event == ZhiPuEvent.INTERRUPTED.value:
                 content = event.data
                 logger.error(f"event error: {content}", end="")
diff --git a/metagpt/roles/role.py b/metagpt/roles/role.py
index 23a7faaae..3e5f268f8 100644
--- a/metagpt/roles/role.py
+++ b/metagpt/roles/role.py
@@ -154,7 +154,7 @@ class Role(BaseModel):
     builtin_class_name: str = ""
 
     _private_attributes = {
-        "_llm": LLM() if not is_human else HumanProvider(),
+        "_llm": None,
         "_role_id": _role_id,
         "_states": [],
         "_actions": [],