Add recent changes to records

[antempus]

For each user, they should have a property (history) that contains the last operations made by other users, when it occurred, qty changed, and change op (rm, add), for each of the coin types. This can be used to prevent a single user from spamming repeated operations or rollback the last change.

Ex:

{
    "id": "user_312",
    "type": "user",
    // user record
    "history": [
        {
            "coinType": "dogecoin",
            "transactions": [
                {
                    "user": "user_1",
                    "time": 1603519700,
                    "qty": 12,
                    "op": "add"
                }
            ]
        },
        {
            "coinType": "litecoin",
            "transactions": [
                {
                    "user": "user_2",
                    "time": 1603512100,
                    "qty": 5,
                    "op": "rm"
                }
            ]
        }
    ]
}

[antempus]

Looking into rate-limiting a single user across all users/coins could also be valuable.