bfUSD Fees

Overview

Fee configurations for bfUSD follow a silent rule: staking, minting, and standard redemption are fee-free, while instant redemption and cross-chain movement carry small factory-set charges. All fee details are exposed through the FeeLibrary helper so that front-ends can display transparent costs.

Fee Library Structures

• struct FeeConfig { uint128 percentageFee; uint128 fixedFee; } – each fee type is represented as a percentage (with precision) plus an optional fixed amount.

• redemptionFee() – returns the applicable fee for standard or instant redemptions, depending on the caller (a whitelist may bypass the percentage portion).

• crossChainFee() – calculates the share burn required when sending funds via LayerZero, covering cross-chain messaging and settlement costs.

Redemption Fees

• Standard redemption: redemptionFee() returns zero for the default path; the only cost is the epoch wait time and manual claim.

• Instant redemption: Charges 0.5% of the redeemed bfUSD and is capped by the redeemer's quota. The fee is collected in bfUSD contracts and emitted through WithdrawalClaimed or immediate redemption events.

Cross-Chain & Other Flows

• LayerZero transfers: crossChainFee() estimates the share-level fee prior to calling send; the vault also emits CrossChainFeeCollected so UIs can highlight the exact cost.

• Fee events: FeeUpdated, FeeWhitelistUpdated, and FeeCollected allow tracking when rates change, when an address is granted discounted treatment, and how much was collected per operation.

Fee Calculation Formula

percentageFee = amount * percentageFeeConfig / FEE_PRECISION
totalFee = percentageFee + fixedFee

The vault reverts when the total fee exceeds the requested output, ensuring users never receive a negative amount.