Config.schema.json

{
    "$schema": "http://json-schema.org/draft-04/schema",
    "title": "Config schema",
    "type": "object",
    "properties": {
        "calendars": {
            "type": "array",
            "default": [],
            "uniqueItems": true,
            "items": {
                "type": "object",
                "title": "calendar",
                "description": "A calendar which should be hosted",
                "properties": { "ip": { "type": "string" }, "port": { "type": "number" } }
            }
        }
    }
}