Question about fee in order structure

[mehrab-hn]

Hey everyone,
I've got a really quick question. The unified order structure has a 'fee' dictionary as follows:

'fee': {
        'currency': 'BTC',        // which currency the fee is (usually quote)
        'cost': 0.0009,           // the fee amount in that currency
        'rate': 0.002,            // the fee rate (if available)
    },

For an order that has no fills yet ('filled' == 0), is it right to have fee['cost'] equal to zero? I mean, should it reflect the 'filled' value? Because we do the same thing for order's cost (cost = filled * price). I'm implementing a new exchange (Nobitex) and want to make sure I'm handling this correctly.

[carlosmiei]

@mehrab-hn Hello, usually we read the fee from the API and yeah it can be zero if the order is still open, that is not an issue, the most important thing is to ensure the fee is correct after the order is filled.

[mehrab-hn]

Great! As I expected. Thanks, @carlosmiei.