Data Structure & Format Conversion

JSON → TypeScript type inference

Infer parseable TypeScript interfaces/types from a JSON sample: nested objects, arrays, null, empty objects, mixed-array unions and quoted special keys; computed locally.

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Inputs and parameters

• input — JSON input
• rootName — Root type name
• outputStyle — Declaration style
• exportDeclaration — Add the export keyword

Real example

{"id":1,"active":true,"deleted":null,"empty":{},"tags":["a",2,{"x":false}],"__proto__":{"polluted":true}}
→ // 空对象推导为 Record<string, never>；它表示「没有已知键」，不是任意对象。

export interface RootTagsItem {
  x: boolean;
}

export interface Root__proto__ {
  polluted: boolean;
}

export interface Root {
  id: number;
  active: boolean;
  deleted: null;
  empty: Record<string, never>;
  tags: Array<string | number | RootTagsItem>;
  "__proto__": Root__proto__;
}

Limits and failure handling

One JSON sample can only describe shapes present in that sample, not every runtime value. Large integers are typed number with an explicit precision warning. This is not a full configurable type system. Input is capped at 1 MiB / depth 64 / 60000 nodes; errors include line and column.

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