Permit USDC with Gelato

permitWithGelato.ts

// These values are for Goerli
const CHAIN_ID = '0x5';
const USDC_ABI = 'import USDC ABI as JSON';
const USDC_ADDRESS = '0x07865c6e87b9f70255377e024ace6630c1eaa37f';
const SEAPORT_CONDUIT_ADDRESS = '0x1E0049783F008A0085193E00003D00cd54003c71';

const PERMIT_DOMAIN = {
  "name": "USD Coin",
  "version": "2",
  "chainId": CHAIN_ID,
  "verifyingContract": USDC_ADDRESS
}

const PERMIT_TYPES = {
  "Permit": [
      {
          "name": "owner",
          "type": "address"
      },
      {
          "name": "spender",
          "type": "address"
      },
      {
          "name": "value",
          "type": "uint256"
      },
      {
          "name": "nonce",
          "type": "uint256"
      },
      {
          "name": "deadline",
          "type": "uint256"
      }
  ]
}

const {wallets} = useWallets();
const wallet = wallets[0];
if (!wallet) throw new Error('No wallet');

const provider = await wallet?.getEthersProvider();
const signer = provider?.getSigner();

// Initialize ethers contract
const usdcContract = new ethers.Contract(USDC_ADDRESS, USDC_ABI, signer);

// Construct permit
const nonce = await usdcContract.nonces(wallet.address);
const value = ethers.utils.parseEther("1000"); // Replace this with the amount of USDC in wei for the permit
const deadline = Math.floor(Date.now() / 1000) + (60 * 60 * 24); // Replace this with your desired permit expiration
const values = {
  owner: wallet.address,
  spender: SEAPORT_CONDUIT_ADDRESS,
  nonce: nonce,
  deadline: deadline,
  value: value
}

// Sign permit
const signature = await signer?._signTypedData(PERMIT_DOMAIN, PERMIT_TYPES, values);
const {v, r, s} = ethers.utils.splitSignature(signature as string);

// Produce transaction calldata
const {data} = await usdcContract.populateTransaction.permit!(wallet.address, SEAPORT_CONDUIT_ADDRESS, values, v, r, s);

const request = {
  chainId: CHAIN_ID,
  target: USDC_ADDRESS,
  data: data as string,
  user: wallet.address
}

// Relay permit transaction with Gelato
const {taskId} = await relay.sponsoredCallERC2771(request, provider, process.env.NEXT_PUBLIC_GELATO_API_KEY as string)

// Then poll taskId for a transaction hash as usual
// https://docs.gelato.network/developer-services/relay/tracking-your-relay-request