How to create and use a SimpleAccount with permissionless.js

SimpleAccount is the original reference sample implementation of an ERC-4337 made by the Eth-Infinitism team. Despite being a reference implementation, it is widely used in production. It allows for a single EOA signer to sign user operations for the account. This guide will show you how to create and use a SimpleAccount with permissionless.js.

Steps

Import the required packages

import { createSmartAccountClient, ENTRYPOINT_ADDRESS_V07 } from "permissionless"
import { signerToSimpleSmartAccount } from "permissionless/accounts"
import {
	createPimlicoBundlerClient,
	createPimlicoPaymasterClient,
} from "permissionless/clients/pimlico"
import { createPublicClient, getContract, http, parseEther } from "viem"
import { privateKeyToAccount } from "viem/accounts"
import { sepolia } from "viem/chains"

Create the clients

First we must create the public, bundler, and (optionally) paymaster clients that will be used to interact with the SimpleAccount.

export const publicClient = createPublicClient({
	transport: http("https://rpc.ankr.com/eth_sepolia"),
})
 
export const paymasterClient = createPimlicoPaymasterClient({
	entryPoint: ENTRYPOINT_ADDRESS_V07,
	transport: http("https://api.pimlico.io/v2/sepolia/rpc?apikey=API_KEY"),
})
 
export const pimlicoBundlerClient = createPimlicoBundlerClient({
	transport: http("https://api.pimlico.io/v2/sepolia/rpc?apikey=API_KEY"),
	entryPoint: ENTRYPOINT_ADDRESS_V07,
})

Create the SimpleAccount

You can create a SimpleAccount with the canonical module addresses by specifying the factory address the account will be deployed from. You can also pass an address to use an already created SimpleAccount.

const simpleAccount = await signerToSimpleSmartAccount(publicClient, {
	signer: privateKeyToAccount("0x..."),
	entryPoint: ENTRYPOINT_ADDRESS_V07,
	factoryAddress: "0x91E60e0613810449d098b0b5Ec8b51A0FE8c8985",
})

Create the smart account client

The smart account client is a permissionless.js client that is meant to serve as an almost drop-in replacement for viem's walletClient.

const smartAccountClient = createSmartAccountClient({
	account: simpleAccount,
	entryPoint: ENTRYPOINT_ADDRESS_V07,
	chain: sepolia,
	bundlerTransport: http("https://api.pimlico.io/v2/sepolia/rpc?apikey=API_KEY"),
	middleware: {
		sponsorUserOperation: paymasterClient.sponsorUserOperation, // optional
		gasPrice: async () => (await pimlicoBundlerClient.getUserOperationGasPrice()).fast, // if using pimlico bundler
	},
})

Send a transaction

Transactions using permissionless.js simply wrap around user operations. This means you can switch to permissionless.js from your existing viem EOA codebase with minimal-to-no changes.

const txHash = await smartAccountClient.sendTransaction({
	to: "0xd8da6bf26964af9d7eed9e03e53415d37aa96045",
	value: parseEther("0.1"),
})

This also means you can also use viem Contract instances to transact without any modifications.

const nftContract = getContract({
	address: "0xFBA3912Ca04dd458c843e2EE08967fC04f3579c2",
	abi: nftAbi,
	client: {
		public: publicClient,
		wallet: smartAccountClient,
	},
})
 
const txHash = await nftContract.write.mint()