Joschka Braun on Jul 2, 2024
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Synthetic data are a great way to bootstrap test data for an AI application if no real production data are available or cannot be used. In this tutorial, we will use Instructor in TypeScript to generate synthetic data for a question-answering task. Instructor is designed to simplify generating structured responses from LLM APIs. It does that by patching the respective model provider API client and using features such as tool use, function call or JSON mode. It will then use user-specified Zod schemas to generate structured responses from the model. To install instructor, zod and openai, run the following command: 
pnpm add @instructor-ai/instructor zod openai
Using instructor amounts to three steps:
  1. Patch the OpenAI client with Instructor
  2. Define a Zod schema for the structured response
  3. Call the chat.completions.create method with the Zod schema as the response_model
Patching the OpenAI client is easy with Instructor: 
import Instructor from "@instructor-ai/instructor";
import OpenAI from "openai"

const oai = new OpenAI({
  apiKey: process.env.OPENAI_API_KEY ?? undefined,
  organization: process.env.OPENAI_ORG_ID ?? undefined
})

const client = Instructor({
  client: oai,
  mode: "TOOLS"
})
Next we will define a Zod schema for the question-answer pairs and require that the answer is a number (to simplify using it to test our application). 
import { z } from "zod"

const QuestionAnswerPair = z.object({
  question: z.string().describe(""),  // optionally use descriptions to steer the synthetic data generation
  answer: z.number().describe("")
})
Note, we can optionally specify descriptions for each attribute which help steering the synthetic data generation and will be used in the prompt. In order to generate a list of question-answer pairs, we define a schema for the list: 
const QuestionAnswerPairsSchema = z.object({
    pairs: z.array(QuestionAnswerPair)
});
type QuestionAnswerPairs = z.infer<typeof QuestionAnswerPairsSchema>
Finally, using Instructor to generate the synthetic data is as simple as calling the chat.completions.create method and specifying the Zod schema as the response_model. We will get back a response of type QuestionAnswerPairs and can save that as our Q&A dataset. 
const generateQuestionAnswerPairs = async (count: number, topic: string): Promise<QuestionAnswerPairs> => {
  return await client.chat.completions.create({
    messages: [{role: "user", content: `Generate ${count} question answer pairs on ${topic}.`}],
    model: "gpt-4o",
    response_model: {schema: QuestionAnswerPairsSchema, name: "QuestionAnswerPairs"},
    temperature: 0.0,  // increase the temperature to get more creative responses
    max_tokens: 1024,
  })
}
This will generate count Q&A pairs on the topic topic and return them as a structured response. To customize this to your use case, you will want to adapt this prompt to include information on your use case.

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Fully Working Code

Below you can see the fully working code: 
// pnpm add @instructor-ai/instructor zod openai
import Instructor from "@instructor-ai/instructor";
import OpenAI from "openai"
import { z } from "zod"
import * as dotenv from "dotenv";

dotenv.config();

const oai = new OpenAI({
  apiKey: process.env.OPENAI_API_KEY ?? undefined,
  organization: process.env.OPENAI_ORG_ID ?? undefined
})

const client = Instructor({
  client: oai,
  mode: "TOOLS"
})

const QuestionAnswerPair = z.object({
  // can optionally use descriptions which will be used in the prompt
  question: z.string().describe(""),
  answer: z.number().describe("")
})
const QuestionAnswerPairsSchema = z.object({
    pairs: z.array(QuestionAnswerPair)
});
type QuestionAnswerPairs = z.infer<typeof QuestionAnswerPairsSchema>


const generateQuestionAnswerPairs = async (count: number, topic: string): Promise<QuestionAnswerPairs> => {
  return await client.chat.completions.create({
    messages: [{role: "user", content: `Generate ${count} question answer pairs on ${topic}.`}],
    model: "gpt-4o",
    response_model: {schema: QuestionAnswerPairsSchema, name: "QuestionAnswerPairs"},
    temperature: 0.0,
    max_tokens: 1024,
  })
}

const main = async () => {
  const count = 5;
  const topic = "soccer";

  const qaPairs: QuestionAnswerPairs = await generateQuestionAnswerPairs(count, topic)
  console.log(qaPairs)
}


main().then(() => console.log("Done!"));