### Check for existing issues

- [x] I have searched the existing issues and checked that my issue is not a duplicate.

### What happened?

I follow the step of https://docs.litellm.ai/docs/tutorials/claude_code_websearch, to setup the web search feature, but I comes error after I start the server. the log belows:

02:48:35 - LiteLLM Proxy:DEBUG: proxy_server.py:2562 - setting litellm.num_retries=3 02:48:35 - LiteLLM Proxy:DEBUG: proxy_server.py:2562 - setting litellm.request_timeout=60 02:48:35 - LiteLLM Proxy:DEBUG: callback_utils.py:34 - initializing callbacks=[{'websearch_interception': None}] on proxy 02:48:35 - LiteLLM Proxy:DEBUG: callback_utils.py:294 - attempting to import custom calback={'websearch_interception': None} ERROR: Traceback (most recent call last): File "/Users/jony.huang/.pyenv/versions/3.11.14/lib/python3.11/site-packages/starlette/routing.py", line 694, in lifespan async with self.lifespan_context(app) as maybe_state: File "/Users/jony.huang/.pyenv/versions/3.11.14/lib/python3.11/contextlib.py", line 210, in __aenter__ return await anext(self.gen) ^^^^^^^^^^^^^^^^^^^^^ File "/Users/jony.huang/.pyenv/versions/3.11.14/lib/python…