ai-agents-anthropic-api-using-chatanthropic-from-langchain-community-with--54c16000

THEN Replace the import from langchain_community.chat_models import ChatAnthropic with from langchain_anthropic import ChatAnthropic and install/update the langchain-anthropic package. The new package uses the Messages API and supports Claude-3 models correctly. Streaming also works with the new package.

Old (broken):
from langchain_community.chat_models import ChatAnthropic
llm = ChatAnthropic(model_name="claude-3-opus-20240229")

New (fixed):
pip install -U langchain-anthropic
from langchain_anthropic import ChatAnthropic
llm = ChatAnthropic(model="claude-3-opus-20240229", streaming=True)