Enable gas fees in USDC

1// Encode a call to pay a merchant $5 USDC
2const calls = [
3  {
4    to: usdc.address,
5    abi: usdc.abi,
6    functionName: 'transfer',
7    args: [merchantAddress, 5000000n]
8  }
9];
10
11// Add the paymaster details
12const paymaster = circleTokenPaymaster;
13const paymasterData = encodePacked(
14  ['uint8', 'address', 'uint256', 'bytes'],
15  [
16    0n,             // Reserved for future use
17    usdc.address,   // Token address
18    1000000n,       // Allow $1 USDC maximum to be spent on gas
19    permitSignature // EIP-2612 permit signature from earlier
20  ]
21);
22
23// Use the bundler to estimate the necessary gas fees and limits
24const { standard: fees } = await bundlerClient.request({
25  method: 'pimlico_getUserOperationGasPrice'
26});
27const maxFeePerGas = hexToBigInt(fees.maxFeePerGas);
28const maxPriorityFeePerGas = hexToBigInt(fees.maxPriorityFeePerGas);
29const {
30  callGasLimit,
31  preVerificationGas,
32  verificationGasLimit,
33  paymasterPostOpGasLimit,
34  paymasterVerificationGasLimit
35} = await bundlerClient.estimateUserOperationGas({
36  account,
37  calls,
38  paymaster,
39  paymasterData
40});
41
42// Construct the entire user op
43const userOp = {
44  account,
45  calls,
46  callGasLimit,
47  preVerificationGas,
48  verificationGasLimit,
49  paymaster,
50  paymasterData,
51  paymasterVerificationGasLimit,
52  paymasterPostOpGasLimit,
53  maxFeePerGas,
54  maxPriorityFeePerGas
55};
56

1const userOpHash = await bundlerClient.sendUserOperation(userOp);
2const userOpReceipt = await bundlerClient.waitForUserOperationReceipt({
3  hash: userOpHash
4});
5