LangChainAdapter

import { CopilotRuntime, LangChainAdapter } from "@copilotkit/runtime";
import { ChatOpenAI } from "@langchain/openai";
 
const copilotKit = new CopilotRuntime();
 
const model = new ChatOpenAI({
  model: "gpt-4o",
  apiKey: "<your-api-key>",
});
 
const serviceAdapter = new LangChainAdapter({
  chainFn: async ({ messages, tools }) => {
    return model.stream(messages, { tools });
  }
});
 
return copilotKit.streamHttpServerResponse(req, res, serviceAdapter);