How to batch an approve and a swap into one transaction

import { createSmartAccountClient } from "permissionless"
import { toSimpleSmartAccount } from "permissionless/accounts"
import { createPimlicoClient } from "permissionless/clients/pimlico"
import { createPublicClient, type Hex, http } from "viem"
import { entryPoint07Address } from "viem/account-abstraction"
import { privateKeyToAccount } from "viem/accounts"
import { base } from "viem/chains"
 
const pimlicoUrl = `https://api.pimlico.io/v2/${base.id}/rpc?apikey=YOUR_PIMLICO_API_KEY`
 
const publicClient = createPublicClient({
	chain: base,
	transport: http("https://mainnet.base.org"),
})
 
const pimlicoClient = createPimlicoClient({
	chain: base,
	transport: http(pimlicoUrl),
	entryPoint: {
		address: entryPoint07Address,
		version: "0.7",
	},
})
 
// The user's signer, for example an embedded wallet or passkey signer
const owner = privateKeyToAccount(process.env.PRIVATE_KEY as Hex)
 
const account = await toSimpleSmartAccount({
	client: publicClient,
	owner,
	entryPoint: {
		address: entryPoint07Address,
		version: "0.7",
	},
})
 
const smartAccountClient = createSmartAccountClient({
	account,
	chain: base,
	bundlerTransport: http(pimlicoUrl),
	// Remove `paymaster` if the account pays its own gas in ETH
	paymaster: pimlicoClient,
	userOperation: {
		estimateFeesPerGas: async () => {
			return (await pimlicoClient.getUserOperationGasPrice()).fast
		},
	},
})

import type { Address } from "viem"
 
// The fields most swap routers and aggregator APIs return for an exact-input quote.
// Map your provider's response onto this shape.
type SwapQuote = {
	to: Address // router contract to call
	data: Hex // swap calldata, with the minimum output (slippage limit) encoded in it
	value: bigint // native value to send, 0n when selling an ERC-20
	allowanceTarget: Address // contract that pulls the sell token
	sellAmount: bigint
}
 
declare function getSwapQuote(params: {
	chainId: number
	sellToken: Address
	buyToken: Address
	sellAmount: bigint
	taker: Address // the address that executes the swap: the smart account
	slippageBps: number
}): Promise<SwapQuote>
 
const USDC = "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913" // USDC on Base
const WETH = "0x4200000000000000000000000000000000000006" // WETH on Base
 
const quote = await getSwapQuote({
	chainId: base.id,
	sellToken: USDC,
	buyToken: WETH,
	sellAmount: 100_000_000n, // 100 USDC
	taker: account.address,
	slippageBps: 50,
})

import { erc20Abi } from "viem"
 
const calls = [
	{
		to: USDC,
		abi: erc20Abi,
		functionName: "approve",
		args: [quote.allowanceTarget, quote.sellAmount],
	},
	{
		to: quote.to,
		value: quote.value,
		data: quote.data,
	},
] as const

const userOpHash = await smartAccountClient.sendUserOperation({ calls })
 
const receipt = await smartAccountClient.waitForUserOperationReceipt({
	hash: userOpHash,
})
 
if (!receipt.success) {
	throw new Error(`Swap reverted: ${receipt.reason ?? "unknown reason"}`)
}
 
console.log(`Approve + swap included: https://basescan.org/tx/${receipt.receipt.transactionHash}`)