{
    "$id": "https://schema.owlboard.info/data-ingress/message-envelope.schema.json",
    "$schema": "https://json-schema.org/draft-07/schema#",
    "title": "MessageEnvelope",
    "type": "object",
    "properties": {
        "service_name": {
            "type": "string",
            "description": "Name of the service submitting the update"
        },
        "service_id": {
            "type": "string",
            "description": "ID of the service sending the message - usually a hostname"
        },
        "data_type": {
            "type": "string",
            "enum": ["file"],
            "description": "The type of data contained in this message object"
        },
        "sent_timestamp": {
            "type": "integer",
            "description": "Unix timestamp representing the time the message was sent"
        },
        "data_kind": {
            "type": "string",
            "enum": ["pis", "timetable", "knowledgebase", "darwin_schedule", "darwin_ts", "darwin_ref"],
            "description": "The data type contained in the message.  Currently supported PIS: PIS Data, Timetable: CIF or VSTP Data, Knowledgebase: Station Data"
        },
        "payload": {}
    },
    "required": ["service_name", "service_id", "data_type", "sent_timestamp"],
    "additionalProperties": false
}