Fees

Protocolink charges fees based on the token amount and transaction type

This page explains the fee mechanism in the Protocolink contracts. The overview fee structure can be found at Fee Structure.

Protocolink calculates the fees on-chain or off-chain depending on the user called function. When users call the Protocolink contract directly (e.g., Execute Transactions), Protocolink calculates the fees on-chain. When users call the Protocolink contract with API data (e.g., Execute Transactions with API Data), Protocolink charges the off-chain fee.

On-Chain Fee

If users call the Router contract without the API data, Protocolink will calculate and charge the on-chain fee in the execute() function. The on-chain fee is charged from the token amounts transferred in the transaction. For ERC-20 tokens, the on-chain fee is charged in the _doPermit2() function, and for native tokens, the on-chain fee is charged in the _chargeByMsgValue() function. Protocolink charges the fee from the Agent.

function execute(
    bytes[] calldata permit2Datas,
    DataType.Logic[] calldata logics,
    address[] calldata tokensReturn
) external payable {
    if (msg.sender != router) revert NotRouter();
    _doPermit2(permit2Datas, true);
    _chargeByMsgValue();
    _executeLogics(logics, true);
    _returnTokens(tokensReturn);
}

Protocolink also charges the flash loan fee before returning the control flow back to flash loan services. You can find out more details in the AaveV3FlashloanCallback.

Off-Chain Fee

If users call the Router contract with API data, Protocolink will charge the off-chain fee in the executeWithSignerFee() function. The fees are calculated in Protocolink's API server off-chain and are charged by token types. If the token is an ERC-20 token, the fee is charged from the user address. If the token is a native token, the fee is charged from the Agent address.

function executeWithSignerFee(
    bytes[] calldata permit2Datas,
    DataType.Logic[] calldata logics,
    DataType.Fee[] calldata fees,
    bytes32[] calldata referrals,
    address[] calldata tokensReturn
) external payable {
    if (msg.sender != router) revert NotRouter();
    _doPermit2(permit2Datas, false);
    for (uint256 i; i < referrals.length; ) {
        _charge(fees, referrals[i], false);
        unchecked {
            ++i;
        }
    }
    _executeLogics(logics, false);
    _returnTokens(tokensReturn);
}