Bumping RBF Enabled Transaction Fees using BDK-Kotlin

A quick guide on how to use the BDK-Kotlin 0.8.0 library to bump Replace-By-Fee(RBF) enabled transaction fees. You can use the Padawan Wallet and dev-kit open-source projects as reference.

TxBuilder

With the TxBuilder() you can create the transaciton as per usual.

var txBuilder = recipientList.fold(TxBuilder()) { builder, recipient ->
    builder.addRecipient(recipient.address, recipient.amount)
}
txBuilder = txBuilder.enableRbf()
txBuilder = txBuilder.feeRate(satPerVbyte = feeRate)
return txBuilder.finish(wallet)

As you can see we are just adding the recipient address and amount normally, while adding a .enableRBF() method. Creating the new transaction to replace that one will be covered in a different blog post since that is a whole separate issue with tons of UI etc.