ProtocolFee.sol

Collects and distributes the 4% APR AsiliChain protocol margin from every loan repayment. All fee rates are annualized percentages on principal (same as interest). Controlled by a 3-of-5 multisig. Transparent on-chain — every fee collection is publicly auditable.

Fee Structure

Every auto-repayment distributes as follows (rates are APR on principal):

  Gross repayment from buyer USDC payment
        │
        ├── Principal + MFI interest (10% APR) → LendingVault MFI pool (repaid)
        ├── 4% APR protocol fee                → ProtocolFee.sol (this contract)
        ├── 2% APR credit loss reserve         → LendingVault reserve buffer
        └── Net balance                        → Farmer via Fonbnk

  Total cost to farmer: 10% + 4% + 2% = 16% APR

Fee Allocation (Protocol Treasury)

The 4% protocol fee collected by this contract is allocated by governance vote:

Allocation	Percentage	Purpose
Protocol operations	40%	API infrastructure, Hedera HCS fees, Pinata costs
Development reserve	30%	Smart contract upgrades, audits, new integrations
Credit loss backstop	20%	Additional insurance beyond per-loan reserve
Community / impact	10%	Cooperative training, field agent support

Interface

// State variables — auto-generated public getters
uint256 public totalCollected;      // cumulative USDC received
uint256 public totalDistributed;    // cumulative USDC sent out
address public usdcToken;           // USDC token address (immutable)

// Core functions
function collect(uint256 amountUsdc) external onlyRole(VAULT_ROLE);

function distribute(
    address recipient,
    uint256 amount,
    string calldata purpose           // ← required, e.g. "Operations Q3 2026"
) external onlyRole(MULTISIG_ROLE);

function pendingDistribution()
    external view returns (uint256);  // totalCollected - totalDistributed

Push-Model Collection

Important: collect() does not pull USDC from LendingVault.

The correct flow is:

1. LendingVault calls usdc.transfer(protocolFeeAddr, amount)
2. LendingVault then calls collect(amount) to record the arrival
3. ProtocolFee emits FeeCollected with running total

This separation means ProtocolFee never holds a USDC allowance on behalf of LendingVault. It simply records what has already arrived.

Distribution Rules

Check	Revert if violated
recipient != address(0)	"ProtocolFee: zero recipient"
amount > 0	"ProtocolFee: zero amount"
bytes(purpose).length > 0	"ProtocolFee: empty purpose"
amount <= pendingDistribution()	"ProtocolFee: insufficient balance"

Multisig Governance

Protocol fee withdrawals require 3-of-5 MULTISIG_ROLE approval. Signers at launch:

Signer	Role
AsiliChain founding team wallet 1	Co-founder
AsiliChain founding team wallet 2	Co-founder
Independent technical advisor	External signer
MFI representative wallet	Institutional accountability
Reserved	Future: community / MAAIF observer

This prevents unilateral treasury withdrawal and provides institutional confidence for MFI partners.

Events

event FeeCollected(
    uint256 amountUsdc,
    uint256 totalCollectedToDate,
    uint256 timestamp
);

event FeeDistributed(
    address indexed recipient,
    uint256         amountUsdc,
    string          purpose,
    uint256         timestamp
);

These events are permanently readable on Mantle explorer and mirrored to Hedera HCS for the governance audit trail.