Why use a JSON Schema Generator?

When building AI applications, defining strict data structures is critical. Language models like GPT-4 and Claude often require explicit JSON Schemas or Zod schemas (via libraries like Vercel AI SDK) when using Function Calling or Structured Outputs.

Writing these schemas manually for deep, nested JSON objects is incredibly tedious and prone to typos. Vakaso JSON Schema Generator completely automates this process entirely in your web browser. Just paste a sample API response or payload, and instantly receive production-ready code.

Supported Output Formats

TypeScript Interfaces: Generates standard TS interfaces. Perfect for dropping into your React components or Node.js backends.
Zod Schemas: Generates z.object() validation schemas. Essential for validating LLM outputs safely at runtime.
JSON Schema: Generates strict JSON schemas compatible with OpenAI's structured output format requirements.

Frequently Asked Questions

Is the code generated locally?

Yes. Just like the rest of Vakaso, the JSON parser runs 100% in your browser. Your JSON payload is never uploaded to our servers.

What happens to nested arrays?

The parser automatically recurses into nested arrays and objects to define nested Zod models or TypeScript interfaces.

How does it handle null values?

Currently, null values are cast to any in TypeScript and z.any() in Zod since the true type cannot be perfectly inferred.

Can I use this for OpenAI Function Calling?

Absolutely. If you want to use OpenAI Structured Outputs, select "JSON Schema (Draft 7)" and paste the resulting schema directly into your API call.