rojo/test-project/src/hello.model.json

{
  "name": "hello",
  "className": "Model",
  "children": [
    {
      "name": "Some Part",
      "className": "Part",
      "children": [],
      "properties": {}
    },
    {
      "name": "Some StringValue",
      "className": "StringValue",
      "children": [],
      "properties": {
        "Value": {
          "type": "string",
          "value": "Hello, world!"
        }
      }
    }
  ],
  "properties": {}
}