{
    "$schema": "http://json-schema.org/draft-04/schema",
    "definitions": {
        "operation": {
            "enum": [
                "insert",
                "update",
                "delete"
            ]
        }
    },
    "type": "object",
    "properties": {
        "operation": {
            "$ref": "#/definitions/operation"
        }
    },
    "required": [
        "operation"
    ],
    "additionalProperties": false
}