JSON Schema Integration

QuickModel can export any model as a JSON Schema Draft-07 object, and can reconstruct a QModel class from an existing JSON Schema. This enables interoperability with any tool that consumes JSON Schema: form generators, API validators, documentation generators, OpenAPI tooling, and more.

Exporting a JSON Schema from a QModel class

Import quickmodel/schema once to register the generators, then call getSchema('json') on any model class:

import 'quickmodel/schema';
import { QModel, Quick } from 'quickmodel';

interface IUser {
	name: string;
	birth: Date;
	score: number;
	active: boolean;
}

@Quick({ birth: Date, score: Number, active: Boolean })
class User extends QModel<IUser> {
	declare name: string;
	declare birth: Date;
	declare score: number;
	declare active: boolean;
}

const schema = User.getSchema('json');
/*
{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "type": "object",
  "title": "User",
  "properties": {
    "name":   { "type": "string" },
    "birth":  { "type": "string", "format": "date-time" },
    "score":  { "type": "number" },
    "active": { "type": "boolean" }
  },
  "required": ["name", "birth", "score", "active"]
}
*/

The returned value is a plain Record<string, unknown> — a live object ready to use directly in any JSON Schema-compatible API.

fromSchema: generating a QModel class from a JSON Schema

fromSchema('json', ...) accepts a JSON Schema object and generates TypeScript source code for a QModel class:

import 'quickmodel/schema';

const existingSchema = {
	$schema: 'http://json-schema.org/draft-07/schema#',
	type: 'object',
	title: 'Product',
	properties: {
		name: { type: 'string' },
		price: { type: 'number' },
		inStock: { type: 'boolean' },
		tags: { type: 'array', items: { type: 'string' } },
	},
	required: ['name', 'price'],
};

const code = QModel.fromSchema('json', existingSchema, 'Product');
// → TypeScript source string for class Product extends QModel<IProduct>

// Save to disk and import:
// fs.writeFileSync('src/models/product.model.ts', code);

This is scaffolding — the output is code to save as a .ts file. Once saved, import and instantiate normally.

Round-trip: QModel → JSON Schema → QModel class

import 'quickmodel/schema';

const jsonSchema = User.getSchema('json'); // export
const code = QModel.fromSchema('json', jsonSchema, 'User'); // regenerate class
// code is valid TypeScript defining class User extends QModel<IUser>

Use cases

AJV validation

getSchema('json') and getSchema('ajv') return structurally identical objects — both work with AJV:

import Ajv from 'ajv';
import 'quickmodel/schema';

const ajv = new Ajv();
const validate = ajv.compile(User.getSchema('json'));

const isValid = validate(req.body);
if (!isValid) console.error(ajv.errorsText(validate.errors));

Fastify / Hono schema validation

// Fastify
fastify.post(
	'/users',
	{
		schema: { body: User.getSchema('json') },
	},
	async (req) => {
		const user = new User(req.body);
		return user.$qSerialize();
	}
);

JSON Schema in OpenAPI documents

import 'quickmodel/schema';

const openApiDoc = {
	components: {
		schemas: {
			User: User.getSchema('json'),
			Order: Order.getSchema('json'),
		},
	},
};

Form generation (react-jsonschema-form, etc.)

import Form from '@rjsf/core';
import 'quickmodel/schema';

const jsonSchema = User.getSchema('json');

// Use directly with react-jsonschema-form
<Form schema={jsonSchema} onSubmit={({ formData }) => {
  const user = new User(formData);
  // types coerced by QModel
}} />

All 13 schema formats

getSchema() supports 13 formats — JSON Schema is the most portable:

Format	Use case
'json'	JSON Schema Draft-07 — universal
'openapi'	OpenAPI 3.0 component schemas
'ajv'	AJV validator (same structure as json)
'typescript'	TypeScript interface source string
'graphql'	GraphQL SDL type string
'prisma'	Prisma model block string
'mongo'	Mongoose schema definition
'zod'	Zod schema source string
'valibot'	Valibot schema source string
'yup'	Yup schema source string
'drizzle'	Drizzle ORM table definition string
'typebox'	TypeBox schema source string
'effect-schema'	Effect Schema source string

See also

• OpenAPI Integration — OpenAPI 3.0 schema generation
• AJV Integration — JSON Schema validation with AJV
• Schema Generation — complete getSchema() reference
• Transformers — how types map to JSON Schema properties