Next.js AI App with Vercel AI SDK: Streaming, Tool Calling & Structured Output

The integration of AI into web applications has moved from being a luxury to a necessity. To stay competitive, developers need tools that can handle high-frequency interactions with low latency.

The Streaming Revolution

With the Vercel AI SDK, we can now stream responses directly to the client. This significantly improves the perceived performance of the app by showing users content as it's being generated.

import { streamText } from 'ai';

export async function POST(req) {
  const { messages } = await req.json();
  const result = await streamText({
    model: openai('gpt-4-turbo'),
    messages,
  });
  return result.toDataStreamResponse();
}

Structured Outputs and Tools

One of the most powerful features is the ability to call tools. This allows your AI to perform actions like searching a database or making an API call, and then returning the result in a structured format.

• Use Zod for schema validation in structured outputs.
• Always implement rate limiting to protect your API costs.
• Leverage edge functions for low-latency AI streaming.