How to use @langchain/react

LangSmith Product Help
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5

hi @whatCanIsay321

If your backend is Python langgraph dev, @langchain/react@1.0.1 is not usable with it yet. The Python Agent Server does not expose POST /threads/{thread_id}/commands or POST /threads/{thread_id}/stream/events.

Use the legacy SDK hook instead:

npm install @langchain/langgraph-sdk

import { useStream } from "@langchain/langgraph-sdk/react";

const stream = useStream({
  apiUrl: "http://localhost:2024",
  assistantId: "agent",
});

Only use @langchain/react@1.x today if you serve the agent with the JS/TS @langchain/langgraph-api>=1.2.0 server. Do not try to fix this with paths - the protocols differ, not just the URLs.