event.json

{
    "$schema": "http://json-schema.org/draft-04/schema#",
    "title": "Event",
    "description": "Shared schema for domain events",
    "properties": {
        "data": {
            "description": "Arbitrary data detailing the event",
            "type": "object"
        },
        "id": {
            "description": "The event's UUID",
            "type": "string"
        },
        "time": {
            "description": "An explanation about the purpose of this instance.",
            "title": "Time schema.",
            "type": "string",
            "format": "date-time"
        },
        "type": {
            "description": "The event's type",
            "type": "string"
        },
        "version": {
            "description": "The version of the domain unit described by this event",
            "type": "integer"
        }
    },
    "required": [
        "id",
        "type",
        "time",
        "version",
        "data"
    ],
    "type": "object"
}

user_created_event.json

{
    "$schema": "http://json-schema.org/draft-04/schema#",
    "title": "Event: user_changed_name",
    "description": "Event that occurs when a user changes his/her name",
    "properties": {
        "meta": {
            "$ref": "event.json",
            "type": {
                "type": "string",
                "pattern": "^user_changed_name$"
            }
        },
        "data": {
            "properties": {
                "id": {
                    "description": "The UUID given to the user",
                    "type": "string"
                },
                "name": {
                    "description": "The user's complete name",
                    "type": "string"
                }
            },
            "required": [
                "id",
                "name"
            ],
            "type": "object"
        }
    },
    "type": "object"
}