What Are the Fee-Bumping Rules (E.g. Minimum Fee Increase) for a BIP125 RBF Replacement?

BIP125, the Opt-in RBF standard, specifies two primary fee-bumping rules for a replacement transaction. First, the replacement transaction's total absolute fee must be greater than the original transaction's fee plus the fee required to cover the new transaction's size.

Second, the replacement must pay a higher fee rate (sat/vbyte) than the original. This ensures the replacement is always more economically attractive to miners and prevents spamming the network with marginally higher-fee transactions.