Json2Zod

A CLI tool and library to convert JSON structures into Zod schemas — with optional .openapi({ example }) generation, perfect for tools like:

• zod-openapi
• @asteasolutions/zod-to-openapi
• @anatine/zod-openapi

This feature saves significant time when transforming example JSON data into Zod + OpenAPI-compatible schemas.

---

Table of Contents

• Features
• Output Example
• Browser Usage
• Installation
• CLI Usage
  • Passing JSON as an Argument
  • Piping JSON from a File or Stdin
  • Including OpenAPI Examples
  • Help Message
• Programmatic Usage
• Development
• License

---

Features

• ✅ Automatic Zod Schema Generation — Infers types like z.string(), z.number(), z.boolean(), z.null(), z.object(), and z.array() from any JSON.
• 🔁 Recursive Type Inference — Handles deeply nested structures.
• 📦 Optional OpenAPI Examples — Add .openapi({ example }) metadata with a flag or programmatically.
• 💻 CLI Tool — Generate schemas from the command line via JSON input or piping.
• 📚 Library/API — Use the core logic in your JS/TS apps.

---

Output Example

Input JSON

{
  "name": "Jane",
  "age": 25,
  "tags": ["developer", "typescript"],
  "settings": {
    "darkMode": true
  }
}

Output (Zod Schema)

export const schema = z.object({
  name: z.string(),
  age: z.number(),
  tags: z.array(z.string()),
  settings: z.object({
    darkMode: z.boolean()
  })
});

Output with OpenAPI Examples

Using the --add-openapi-examples flag or { addOpenApiExamples: true } programmatically:

export const schema = z.object({
  name: z.string().openapi({ example: "Jane" }),
  age: z.number().openapi({ example: 25 }),
  tags: z.array(z.string().openapi({ example: "developer" })).openapi({ example: ["developer", "typescript"] }),
  settings: z.object({
    darkMode: z.boolean().openapi({ example: true })
  }).openapi({ example: { darkMode: true } })
});

---

Browser Usage

You can also use json2zod directly in your browser via the live playground:

🌐 json2zod.pages.dev

No installation needed — paste your JSON, configure options, and get your Zod schema instantly!

---

Installation

Install the package via npm:

npm install json2zod
# or globally
npm -g install json2zod

Or with your favorite package manager:

pnpm add json2zod
# or
bun add json2zod

---

CLI Usage

After installing globally or using npx:

npx json2zod '{"example": "json"}'

Or use directly from your project scripts.

Passing JSON as an Argument

For quick conversions:

json2zod '{"name": "Alice", "age": 30, "address": {"city": "New York"}}'

Piping JSON from a File or Stdin

From a file:

cat data.json | json2zod

From stdin:

echo '{"item": "Book", "id": 123}' | json2zod

Including OpenAPI Examples

Add .openapi({ example }) metadata for each field:

cat your_data.json | json2zod --add-openapi-examples

This is useful for OpenAPI tools like:

• zod-openapi
• @asteasolutions/zod-to-openapi
• @anatine/zod-openapi

Help Message

Display usage and available flags:

json2zod --help

---

Programmatic Usage

You can import the schema generator directly in your JS/TS project:

import { generateZodSchema } from 'json2zod';

const json = {
  name: "Jane",
  age: 25,
  tags: ["developer", "typescript"],
  settings: {
    darkMode: true
  }
};

// Without OpenAPI examples
console.log(generateZodSchema(json));

// With OpenAPI examples
console.log(generateZodSchema(json, { addOpenApiExamples: true }));

Supports arrays too:

const input = [
  { id: 1, title: "First" },
  { id: 2, title: "Second" }
];

console.log(generateZodSchema(input));

---

Development

To contribute:

git clone https://github.com/Drarox/json2zod.git
cd json2zod
npm install
npm run build

---

License

MIT License — see the LICENSE file for details.