Bitcoin-S has a
FeeProvider that is used to fetch fee rates.
Currently, Bitcoin-s has a couple implemented, one being a
BitcoindRpcClient, which will use
estimateSmartFee to calculate a fee rate.
Another uses bitcoiner.live's api to get a fee rate.
FeeProvider can be passed to a
Wallet which will be used to calculate fees for transactions when one is not specified.
HttpFeeRateProvider is a
FeeProvider that uses an outside API to get fee rates.
These can be hooked up to any website's API as long as you can provide a
URI and a function to convert the response to a
There also exists
CachedHttpFeeRateProvider, which will cache the response for the
cacheDuration as to prevent hitting request limits and save on api calls.
BitcoinerLiveFeeRateProvider's implementation for an example.