PHP - Bitcoind sets up wrong transaction fee

Question

I'm using Bitcoin API EasyBitcoin-PHP

And also i have my custom transaction fee, that i'd like to pay per each Kb. The problem is that when i used bitcoind v.0.10.2 that was fine and i saw my custom fee (0.0002) in each transaction. But when i've updated to v. 0.13.0 - it just won't work as it should. Here is the simple code, that i'm testing now

$bitcoin = new Bitcoin($user, $password, $host, $port);

$result = $bitcoin->settxfee(0.0002); //returns true
$newTxId = $bitcoin->sendtoaddress('144YsrgtDmRSPC8wUBXLxByCcQAEbV1EUB', 0.001); //returns c3a2fceed1c25624aee8e957c644813bf38808260aad607e623c68e182371ac9

And as you can see in this transaction the fee is 0.000045 BTC, not 0.0002 BTC.

I know, that there was a bug in prev version of bitcoind according to fee rounding, but in new version this bug should be fixed.

Maybe there is another trouble here?

Answer 1

The value you specify for custom fee is in fee per kilobyte. Until recently, the "size" for fee computations was always rounded up to 1 kilobyte anyway, leading some people to believe that the amount they're setting is the absolute amount instead.

Your transaction is 225 bytes, and pays 0.000045 BTC fee. That is exactly 0.0002 BTC per 1000 bytes, so it is working as intended.