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• I am a LangChain maintainer, or was asked directly by a LangChain maintainer to create an issue here.

Issue Content

Technically something like this should work:

import { createAgent } from "langchain";
import { ChatXAI } from "@langchain/xai";

const model = new ChatXAI({
  model: "grok-4-fast",
});

const agent = createAgent({
  model,
  tools: [
    {
      type: "web_search",
      filters: { excluded_domains: ["wikipedia.org"] },
    },
  ],
});

const result = await agent.invoke({ messages: "What is LangChainJS?" });

console.log(result);

However our @langchain/xai integration seems outdated and doesn't support latest features we have in the ChatOpenAI class. We should revise the integration and bring it up to speed.

Any community contribution is welcome!