diff --git a/lagent/actions/web_browser.py b/lagent/actions/web_browser.py
index 235e149..29f7594 100644
--- a/lagent/actions/web_browser.py
+++ b/lagent/actions/web_browser.py
@@ -18,7 +18,6 @@
 from asyncache import cached as acached
 from bs4 import BeautifulSoup
 from cachetools import TTLCache, cached
-from duckduckgo_search import DDGS, AsyncDDGS
 
 from lagent.actions.base_action import AsyncActionMixin, BaseAction, tool_api
 from lagent.actions.parser import BaseParser, JsonParser
@@ -78,6 +77,8 @@ def search(self, query: str, max_retry: int = 3) -> dict:
 
     @acached(cache=TTLCache(maxsize=100, ttl=600))
     async def asearch(self, query: str, max_retry: int = 3) -> dict:
+        from duckduckgo_search import AsyncDDGS
+
         for attempt in range(max_retry):
             try:
                 ddgs = AsyncDDGS(timeout=self.timeout, proxy=self.proxy)
@@ -92,6 +93,8 @@ async def asearch(self, query: str, max_retry: int = 3) -> dict:
         raise Exception('Failed to get search results from DuckDuckGo after retries.')
 
     async def _async_call_ddgs(self, query: str, **kwargs) -> dict:
+        from duckduckgo_search import DDGS
+
         ddgs = DDGS(**kwargs)
         try:
             response = await asyncio.wait_for(
@@ -215,7 +218,8 @@ class BraveSearch(BaseSearch):
         topk (int): The number of search results returned in response from API search results.
         region (str): The country code string. Specifies the country where the search results come from.
         language (str): The language code string. Specifies the preferred language for the search results.
-        extra_snippets (bool): Allows retrieving up to 5 additional snippets, which are alternative excerpts from the search results.
+        extra_snippets (bool): Allows retrieving up to 5 additional snippets, which are alternative excerpts from the
+        search results.
         **kwargs: Any other parameters related to the Brave Search API. Find more details at
             https://api.search.brave.com/app/documentation/web-search/get-started.
     """
diff --git a/lagent/llms/anthropic_llm.py b/lagent/llms/anthropic_llm.py
index 8cd7802..fe50bfa 100644
--- a/lagent/llms/anthropic_llm.py
+++ b/lagent/llms/anthropic_llm.py
@@ -9,7 +9,7 @@
 from anthropic import NOT_GIVEN
 from requests.exceptions import ProxyError
 
-from lagent.llms import AsyncBaseAPILLM, BaseAPILLM
+from .base_api import AsyncBaseAPILLM, BaseAPILLM
 
 
 class ClaudeAPI(BaseAPILLM):
@@ -222,7 +222,12 @@ def __init__(
         retry: int = 5,
         key: Union[str, List[str]] = 'ENV',
         proxies: Optional[Dict] = None,
-        meta_template: Optional[Dict] = None,
+        meta_template: Optional[Dict] = [
+            dict(role='system', api_role='system'),
+            dict(role='user', api_role='user'),
+            dict(role='assistant', api_role='assistant'),
+            dict(role='environment', api_role='user'),
+        ],
         temperature: float = NOT_GIVEN,
         max_new_tokens: int = 512,
         top_p: float = NOT_GIVEN,
@@ -278,8 +283,7 @@ async def chat(
         assert isinstance(inputs, list)
         gen_params = {**self.gen_params, **gen_params}
         tasks = [
-            self._chat(self.template_parser(messages), **gen_params)
-            for messages in ([inputs] if isinstance(inputs[0], dict) else inputs)
+            self._chat(messages, **gen_params) for messages in ([inputs] if isinstance(inputs[0], dict) else inputs)
         ]
         ret = await asyncio.gather(*tasks)
         return ret[0] if isinstance(inputs[0], dict) else ret
@@ -333,7 +337,7 @@ async def _chat(self, messages: List[dict], **gen_params) -> str:
             str: The generated string.
         """
         assert isinstance(messages, list)
-
+        messages = self.template_parser(messages)
         data = self.generate_request_data(model_type=self.model_type, messages=messages, gen_params=gen_params)
         max_num_retries = 0
 
diff --git a/requirements/optional.txt b/requirements/optional.txt
index 75645db..0ae76df 100644
--- a/requirements/optional.txt
+++ b/requirements/optional.txt
@@ -1,3 +1,4 @@
+duckduckgo_search==5.3.1b1
 google-search-results
 lmdeploy>=0.2.5
 pillow
diff --git a/requirements/runtime.txt b/requirements/runtime.txt
index bb28b27..ac0b85c 100644
--- a/requirements/runtime.txt
+++ b/requirements/runtime.txt
@@ -4,7 +4,6 @@ arxiv
 asyncache
 asyncer
 distro
-duckduckgo_search==5.3.1b1
 filelock
 func_timeout
 griffe<1.0