{
    "id": "/PingRequest",
    "title": "Ping Request",
    "type": "object",
    "properties": {
        "checksum": {
            "type": "number"
        },
        "changes": {
            "type": "array",
            "items": {
                "$ref": "/Change"
            }
        },
        "source": {
            "type": "string"
        },
        "sourceIncarnationNumber": {
            "type": "number"
        }
    },
    "required": [
        "checksum",
        "changes",
        "source",
        "sourceIncarnationNumber"
    ],
    "additionalProperties": false
}

{
    "id": "/PingRequest",
    "title": "Ping Request",
    "type": "object",
    "properties": {
        "checksum": {
            "type": "number"
        },
        "changes": {
            "type": "array",
            "items": {
                "$ref": "/Change"
            }
        },
        "source": {
            "type": "string"
        },
        "app": {
            "type": "string"
        },
        "sourceIncarnationNumber": {
            "type": "number"
        }
    },
    "required": [
        "checksum",
        "changes",
        "source",
        "sourceIncarnationNumber"
    ],
    "additionalProperties": false
}

Add optional app field to ping req
Add optional app field to ping req
