{
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "additionalProperties": false,
    "required": ["$sort", "by(x)"],
    "properties": {
        "$sort": {
            "type": "array",
            "items": {
                "type": "integer",
                "minimum": 0
            }
        },
        "by(x)": {
            "type": "string"
        }
    }
}