Generate structured data

Send a prompt and a schema to collect a complete object or array.

This page describes the v0 API from v0.5.1. Use v0 package builds with these examples. Make sure that the service accepts the model ID and request protocol shown below. Install valibot and @valibot/to-json-schema for the schema examples.

These examples use valibot.

This package uses xsschema to convert schemas. Use a schema library from its supported vendor list.

See xsschema for more information.

npm i @xsai/generate-object@0.5.1

Examples

Install the schema converter that your schema version requires before you run these examples.

Read the schema coverage reference.

Object

const { object } = await generateObject({
  apiKey: env.OPENAI_API_KEY!,
  baseURL: 'https://api.openai.com/v1/',
  messages: [
    {
      content: 'Extract the event information.',
      role: 'system'
    },
    {
      content: 'Alice and Bob are going to a science fair on Friday.',
      role: 'user'
    }
  ],
  model: 'gpt-4o',
  schema: v.object({
    date: v.string(),
    name: v.string(),
    participants: v.array(v.string()),
  })
})

Array

const { object: objects } = await generateObject({
  apiKey: env.OPENAI_API_KEY!,
  baseURL: 'https://api.openai.com/v1/',
  messages: [
    {
      content: 'Generate 3 hero descriptions for a fantasy role playing game.',
      role: 'user'
    }
  ],
  model: 'gpt-4o',
  output: 'array', 
  schema: v.object({
    class: v.pipe(
      v.string(),
      v.description('Character class, e.g. warrior, mage, or thief.'),
    ),
    description: v.string(),
    name: v.string(),
  })
})

for (const object of objects) { 
  console.log(object)
}

Result

The examples return structured values that match the declared schemas.