JSON to types API

Generate TypeScript interfaces, Zod schemas, JSON Schema 2020-12, Go structs, Python dataclasses or Pydantic models from one or more JSON samples.

POSThttps://apibox.io.vn/v1/json-to-types

Developer utilities▶ Try it online

Paste a JSON sample in json (or several in samples) and choose lang: typescript, zod, json-schema, go, python (dataclasses), pydantic (v2), a comma-separated list or all. Samples are merged field by field: a field missing from some objects becomes optional, mixed kinds become unions, null makes a field nullable, integers and decimals merge into a number, and a top-level array of objects is read as a list of records of one type.

Nested objects get their own named types from the key (array items are singularised: items → Item, addresses → Address), identical shapes share one type, and strings are tagged with a format when every sample matches: RFC 3339 date-time (→ time.Time, datetime, z.string().datetime()), date, time, UUID, e-mail, URL. With enums=true short string fields with repeated values become literal unions / enums. Keys that are not valid identifiers are quoted (TypeScript, Zod), tagged (Go json:"…") or aliased (Pydantic Field(alias=…)).

The generator is our own (no quicktype): up to 100 samples, 200,000 values and 64 levels of nesting. code holds the first language, output every language requested. Python output uses X | None syntax (Python 3.10+).

Parameters

Name	In	Type	Required	Default
`json`	body	object	no		One JSON sample (any JSON value, or a JSON string).
`samples`	body	array	no		Several samples of the same type (up to 100), merged.
`lang`	body	string	no	`typescript`	`typescript`, `zod`, `json-schema`, `go`, `python`, `pydantic`, a comma list or `all`.
`name`	body	string	no	`Root`	Name of the root type.
`detect_dates`	body	boolean	no	`true`	Detect date-time / date / time strings.
`enums`	body	boolean	no	`false`	Turn short repeated string values into literal unions / enums.

Example

curl -X POST "https://apibox.io.vn/v1/json-to-types" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"json":{"id":1,"name":"An","created_at":"2026-11-10T08:30:00Z","tags":["vip"],"address":{"city":"Hà Nội","zip":null}},"lang":"typescript","name":"Customer"}'

const res = await fetch('https://apibox.io.vn/v1/json-to-types', {
  method: 'POST',
  headers: {
    Authorization: 'Bearer YOUR_API_KEY',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    "json": {
      "id": 1,
      "name": "An",
      "created_at": "2026-11-10T08:30:00Z",
      "tags": [
        "vip"
      ],
      "address": {
        "city": "Hà Nội",
        "zip": null
      }
    },
    "lang": "typescript",
    "name": "Customer"
  }),
});
const data = await res.json();
console.log(data);

import requests

res = requests.post(
    "https://apibox.io.vn/v1/json-to-types",
    headers={"Authorization": "Bearer YOUR_API_KEY"},
    json={"json": {"id": 1, "name": "An", "created_at": "2026-11-10T08:30:00Z", "tags": ["vip"], "address": {"city": "Hà Nội", "zip": None}}, "lang": "typescript", "name": "Customer"},
    timeout=30,
)
print(res.json())

<?php
$ch = curl_init('https://apibox.io.vn/v1/json-to-types');
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_CUSTOMREQUEST => 'POST',
    CURLOPT_HTTPHEADER => ['Authorization: Bearer YOUR_API_KEY', 'Content-Type: application/json'],
    CURLOPT_POSTFIELDS => '{"json":{"id":1,"name":"An","created_at":"2026-11-10T08:30:00Z","tags":["vip"],"address":{"city":"Hà Nội","zip":null}},"lang":"typescript","name":"Customer"}',
]);
$response = curl_exec($ch);
print_r(json_decode($response, true));

Response

{
  "root": "Customer",
  "samples": 1,
  "types": [
    "Customer",
    "Address"
  ],
  "languages": [
    "typescript"
  ],
  "code": "export interface Customer {\n  id: number;\n  name: string;\n  /** format: date-time */\n  created_at: string;\n  tags: string[];\n  address: Address;\n}\n\nexport interface Address {\n  city: string;\n  zip: null;\n}\n",
  "output": {
    "typescript": "(same as code)"
  }
}

Use cases

Type an API response before writing the client
Create a Zod or Pydantic validator from example payloads
Write a JSON Schema for a webhook from real events
Generate Go structs for a third-party JSON API

FAQ

How do I mark fields as optional?

Send several samples in "samples": fields absent from some of them become optional (?, .optional(), pointer + omitempty, = None).

Which Zod version is targeted?

Zod 3 syntax (z.string().datetime(), .email(), .uuid()), which also works in Zod 4.

Are dates detected?

Yes, strings that are RFC 3339 date-times or YYYY-MM-DD dates in every sample; detect_dates=false keeps them as plain strings.

JSON to types API

Parameters

Example

Response

Use cases

FAQ

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Time & Timezone Converter