Generate Object

You can use generateText with Output to generate structured data like JSON. By providing a schema that describes the structure of your desired object, the SDK will validate the generated output and ensure that it conforms to the specified structure.

The Output.object function requires you to provide a schema using zod, a library for defining schemas for JavaScript objects.

http://localhost:3000

View Notifications

Client

Let's create a simple React component that will make a POST request to the /api/completion endpoint when a button is clicked. The endpoint will return the generated object based on the input prompt and we'll display it.

'use client';

import { useState } from 'react';

export default function Page() {
  const [generation, setGeneration] = useState();
  const [isLoading, setIsLoading] = useState(false);

  return (
    <div>
      <div
        onClick={async () => {
          setIsLoading(true);

          await fetch('/api/completion', {
            method: 'POST',
            body: JSON.stringify({
              prompt: 'Messages during finals week.',
            }),
          }).then(response => {
            response.json().then(json => {
              setGeneration(json.notifications);
              setIsLoading(false);
            });
          });
        }}
      >
        Generate
      </div>

      {isLoading ? (
        'Loading...'
      ) : (
        <pre>{JSON.stringify(generation, null, 2)}</pre>
      )}
    </div>
  );
}

Server

Let's create a route handler for /api/completion that will generate an object based on the input prompt. The route will call the generateText function with Output.object from the ai module, which will then generate an object based on the input prompt and return it.

import { generateText, Output } from 'ai';
import { z } from 'zod';

export async function POST(req: Request) {
  const { prompt }: { prompt: string } = await req.json();

  const result = await generateText({
    model: 'openai/gpt-4o',
    system: 'You generate three notifications for a messages app.',
    prompt,
    output: Output.object({
      schema: z.object({
        notifications: z.array(
          z.object({
            name: z.string().describe('Name of a fictional person.'),
            message: z.string().describe('Do not use emojis or links.'),
            minutesAgo: z.number(),
          }),
        ),
      }),
    }),
  });

  return Response.json(result.output);
}

View Example on GitHub