1// Server-side route handler
2import { openai } from "@ai-sdk/openai";
3import { streamText } from "ai";
4
5export async function POST(req: Request) {
6const { messages } = await req.json();
7const result = streamText({
8  model: openai("gpt-4o"),
9  messages,
10});
11return result.toDataStreamResponse();
12}
13
14// Client component
15import { useChat } from "ai/react";
16
17export default function Chat() {
18const { messages, input, handleInputChange, handleSubmit } = useChat();
19
20return (
21  <div>
22    {messages.map(m => <div key={m.id}>{m.content}</div>)}
23    <form onSubmit={handleSubmit}>
24      <input value={input} onChange={handleInputChange} />
25    </form>
26  </div>
27);
28}

1import { ChatOpenAI } from "@langchain/openai";
2import { createReactAgent } from "@langchain/langgraph/prebuilt";
3import { TavilySearchResults } from "@langchain/community/tools/tavily";
4
5const model = new ChatOpenAI({ model: "gpt-4o" });
6const searchTool = new TavilySearchResults();
7
8const agent = createReactAgent({
9llm: model,
10tools: [searchTool],
11});
12
13const result = await agent.invoke({
14messages: [{
15  role: "user",
16  content: "What is the latest Next.js version and its key features?",
17}],
18});