prepareTokenPaymasterUserOp

This method prepares a user operation with token paymaster configuration, including ERC20 token approval. It handles:

1. Checking current token allowance of Smart Account
2. Creating an approval transaction for the token paymaster if needed
3. Preparing the user operation with the approval and user transactions

Usage

import { nexusClient } from "./nexusClient"
 
const userOp = await nexusClient.prepareTokenPaymasterUserOp({
  calls: [
    {
      to: recipientAddress,
      value: 1n,
      data: "0x"
    }
  ],
  feeTokenAddress: "0x...", // ERC20 token address
  customApprovalAmount: usdcFeeAmount // optional
})

Parameters

• calls { to: Address, data: Hex, value: bigint }[]: Array of transactions to be executed
• feeTokenAddress Address: Token address used for paying for the gas
• customApprovalAmount bigint (optional): Custom approval amount for the token paymaster. If not provided, max uint256 will be used

Response

• Promise<Omit<UserOperation<"0.7">, "signature">>: Returns a prepared user operation without signature (will be signed by the Smart Account when sent)

Error Handling

The method will throw an error if:

• Client account is not properly configured
• Paymaster context is not properly configured