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Fee Setup and Management

Setting up fees is essential for your app to interact with both the offchainVM and supported blockchains. There are two types of fees you need to manage:

  1. OffchainVM transaction fees
  2. Onchain transaction sponsorship

OffchainVM Transaction Fees​

OffchainVM transactions require its native gas token. You can:

Transaction fees work similarly to standard blockchain transactions - specify gasPrice and gasLimit or use automatic estimation.

Onchain Transaction Sponsorship​

1. Deposit Sponsorship Tokens to pay for transactions​

First, deposit ETH to the PayloadDeliveryPlug contract on your chosen chain:

cast send <PLUG_ADDRESS> "deposit(address,uint256,address)" \
    0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE \
    <AMOUNT> \
    $COUNTER_APPGATEWAY \
    --value <AMOUNT> \
    --rpc-url $SEPOLIA_RPC \
    --private-key $PRIVATE_KEY
info

Currently only ETH is supported. Support for additional tokens is coming soon.

2. Configure Fee Data​

Set up the FeesData structure for your app:

struct FeesData {
    uint32 feePoolChain;
    address feePoolToken;
    uint256 maxFees;
}

FeesData feesData = FeesData({
    feePoolChain: <chain_slug>,
    feePoolToken: 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE,
    maxFees: <max_fee_per_tx>
});

3. Apply Fee Configuration​

Set the fee configuration in your contracts:

AppGateway(appGateway).setFees(feesData);
Deployer(deployer).setFees(feesData);

or set them in the constructor of the AppGateway and Deployer.

_setFeesData(feesData_);

The FeesData structure is designed to manage fee-related parameters for transactions in a dual-execution environment (offchainVM and onchain). Here's how it's implemented:

FeesData memory feesData = FeesData({
    feePoolChain: 421614,      // Chain ID where fees are collected
    feePoolToken: ETH_ADDRESS, // Token used for fee payments (ETH in this case)
    maxFees: 0.001 ether      // Maximum fee amount allowed
});

FeesData Key Components​

  1. feePoolChain Specifies the blockchain network ID where fees are collected and managed. In this case, it's set to 421614, which appears to be a specific chain ID (possibly a testnet or L2 network).

  2. feePoolToken Defines which token is used for fee payments. Here it's set to ETH_ADDRESS, meaning Ethereum is used as the payment token.

  3. maxFees Sets an upper limit for transaction fees, preventing excessive charges. In this example, it's set to 0.001 ETH.

Dual Purpose Usage​

OffchainVM Transactions

  • Acts as a fee configuration for processing off-chain computations
  • Ensures users have enough balance to cover computational costs
  • Provides a predictable fee structure for off-chain operations

Onchain Transactions

  • Sets parameters for standard blockchain transaction fees
  • Manages gas costs for contract interactions
  • Provides fee limits for user protection

Implementation Context​

The FeesData structure is passed to both the SuperTokenDeployer and SuperTokenAppGateway contracts, ensuring consistent fee handling across the entire system, whether transactions are processed off-chain or on-chain:

SuperTokenDeployer deployer = new SuperTokenDeployer(
    addressResolver,
    owner,
    address(auctionManager),
    FAST,
    SuperTokenDeployer.ConstructorParams({...}),
    feesData
);

SuperTokenAppGateway gateway = new SuperTokenAppGateway(
    addressResolver,
    address(deployer),
    feesData,
    address(auctionManager)
);

Contract Deployment​

1. Deploy to offchainVM​

Deploy your contracts using the DeployGateway.s.sol script by running:

forge script script/super-token/SetupSuperToken.s.sol --broadcast

2. Fund Your App​

After deployment, deposit fees against your SuperTokenAppGateway's address on any supported chain to enable offchainVM to execute transactions on your behalf.

3. Deploy to Target Chains​

Below is an example of how to complete the script DeployContracts.s.sol:

contract DeployContracts is Script {
    function run() public {
        (...)
        SuperTokenDeployer superTokenDeployer = SuperTokenDeployer(<deployerAddress>);
        superTokenDeployer.deployContracts(84532);     // Base Sepolia
        superTokenDeployer.deployContracts(11155420);  // OP Sepolia
        superTokenDeployer.deployContracts(421614);    // Arbitrum Sepolia
    }
}

Use DeployContracts.s.sol to deploy your token to desired chains:

forge script ./script/super-token/DeployContracts.s.sol --broadcast

Deployment typically takes a few minutes. Track deployment status and verify contract addresses using our APIs.