Generate Object

Earlier functions like generateText and streamText gave us the ability to generate unstructured text. However, if you want to generate structured data like JSON, you can provide an Output that describes the structure of your desired object to generateText.

The Output.object function requires you to provide a schema using zod, a library for defining schemas for JavaScript objects. By using zod, you can also use it to validate the generated object and ensure that it conforms to the specified structure.

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

const result = await generateText({
  model: 'openai/gpt-4.1',
  output: Output.object({
    schema: z.object({
      recipe: z.object({
        name: z.string(),
        ingredients: z.array(
          z.object({
            name: z.string(),
            amount: z.string(),
          }),
        ),
        steps: z.array(z.string()),
      }),
    }),
  }),
  prompt: 'Generate a lasagna recipe.',
});

console.log(JSON.stringify(result.output.recipe, null, 2));