Getting Started

Installation

npm install json-as

Use the transform when compiling:

asc assembly/index.ts --transform json-as

Optional performance flags:

asc assembly/index.ts --transform json-as --enable simd

Or configure it in asconfig.json:

{
  "options": {
    "transform": ["json-as"]
  }
}

If you want to inspect generated code during development:

JSON_WRITE=assembly/test.ts asc assembly/test.ts --transform ./transform

First Example

import { JSON } from "json-as";

@json
class Vec3 {
  x: f32 = 0.0;
  y: f32 = 0.0;
  z: f32 = 0.0;
}

const input = '{"x":1.5,"y":2.5,"z":3.5}';
const parsed = JSON.parse<Vec3>(input);
const encoded = JSON.stringify(parsed);

What @json does

json-as is transform-driven. The @json decorator tells the transform to generate serialization and deserialization methods for the class.

That gives you:

• typed object parsing with JSON.parse<T>(...)
• typed serialization with JSON.stringify(...)
• field-level handling for nested classes, arrays, maps, sets, and strings

For dynamic or unknown JSON, use JSON.Value or JSON.Obj instead of @json.