{
    "$schema": "http://json-schema.org/draft-06/schema",
    "additionalProperties": false,
    "properties": {
        "domain": {
            "pattern": "^([a-z0-9]+(-[a-z0-9]+)*\\.)+[a-z]{2,}$",
            "type": "string"
        },
        "selector": {
            "type": "string"
        },
        "url": {
            "_format": "url",
            "type": "string"
        }
    },
    "required": [
        "domain",
        "url",
        "selector"
    ],
    "type": "object"
}