如何在 Next.js 项目中使用 Vercel AI SDK？

npm install ai @ai-sdk/openai @ai-sdk/react

// app/api/chat/route.ts
import { openai } from '@ai-sdk/openai';
import { streamText } from 'ai';

export async function POST(request: Request) {
  const { messages } = await request.json();
  
  const result = streamText({
    model: openai('gpt-5.5'),
    messages,
  });
  
  return result.toDataStreamResponse();
}

'use client';
import { useChat } from '@ai-sdk/react';

export default function Chat() {
  const { messages, input, handleInputChange, handleSubmit } = useChat();
  
  return (
    <div>
      {messages.map(m => (
        <div key={m.id}>{m.content}</div>
      ))}
      <form onSubmit={handleSubmit}>
        <input value={input} onChange={handleInputChange} />
      </form>
    </div>
  );
}