langchain[patch]: Add warning in react agent (#26980)

Author: hinthornw

libs/core/langchain_core/callbacks/manager.py

@@ -2502,7 +2502,8 @@ async def foo(inputs):
             ):
                 print(event)
 
-    .. warning: If using python <= 3.10 and async, you MUST
+    .. warning::
+        If using python <= 3.10 and async, you MUST
         specify the `config` parameter or the function will raise an error.
         This is due to a limitation in asyncio for python <= 3.10 that prevents
         LangChain from automatically propagating the config object on the user's

libs/langchain/langchain/agents/react/agent.py

@@ -27,6 +27,12 @@ def create_react_agent(
     Based on paper "ReAct: Synergizing Reasoning and Acting in Language Models"
     (https://arxiv.org/abs/2210.03629)
 
+    .. warning::
+       This implementation is based on the foundational ReAct paper but is older and not well-suited for production applications.
+       For a more robust and feature-rich implementation, we recommend using the `create_react_agent` function from the LangGraph library.
+       See the [reference doc](https://langchain-ai.github.io/langgraph/reference/prebuilt/#langgraph.prebuilt.chat_agent_executor.create_react_agent)
+       for more information.
+
     Args:
         llm: LLM to use as the agent.
         tools: Tools this agent has access to.