[
    {
        "name": "signature_id",
        "type": "INTEGER",
        "mode": "REQUIRED",
        "description": "signature id"
    },
    {
        "name": "contract_id",
        "type": "INTEGER",
        "mode": "REQUIRED",
        "description": "contract_id"
    },
    {
        "name": "kind",
        "type": "STRING",
        "mode": "REQUIRED",
        "description": "type of signature"
    },
    {
        "name": "added_at",
        "type": "TIMESTAMP",
        "mode": "REQUIRED",
        "description": "when first observed"
    }
]
