JSON Grammar
The JSON grammar describes the elements that you can use in a JSON page object.
Here's a sample outline of a page object.
{
    "elements": [],
    "methods": [],
    "shadow": {
        "elements": []
    },
    "root": true,
    "selector": {
        "css": "one-record-home"
    }
}
For more details, start with Root Elements.