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EIP-7702 Quickstart

EIP-7702 upgrades current Ethereum External Owned Accounts (EOAs) by upgrading them to smart contract accounts

  • Gas sponsorship: abstract away gas fees, allowing third-party sponsorship or payment in ERC-20 tokens
  • Transaction batching: improve UX and security by combining approvals and contract interactions into a single step
  • Permissions: grant specific, limited access to third-parties, enabling use cases like recurring payments
  • Forward compatibility with end-game AA: Remains compatible with ERC-4337 and future native account abstraction.

To learn more about EIP-7702, visit the dedicated 7702 Overview.

In this example, you will learn how to upgrade an EOA to a Smart Account to leverage features such as batching and gas sponsorship

Prerequisites​

  • Sepolia Bundler and Paymaster endpoints from the Dashboard
  • Node and a package manager (yarn or npm)

Here's the complete code for you to reference if you prefer to run directly.

Step 1: Get setup​

  1. Create a new directory for your project:
mkdir candide-eip7702-upgrade-eoa
cd candide-eip7702-upgrade-eoa
yarn init
  1. Install required dependencies
yarn add abstractionkit@0.2.16 dotenv ethers
note

abstractionkit@0.2.16 is the version release with EIP-7702 support before the official upgrade with Pectra.

  1. Configure Environment Variables
  • Create a .env file and add the following environment variables with your own values
.env
CHAIN_ID=11155111
JSON_RPC_NODE_PROVIDER=https://ethereum-sepolia-rpc.publicnode.com
BUNDLER_URL=https://api.candide.dev/bundler/v3/sepolia/APY_KEY
PAYMASTER_URL=https://api.candide.dev/paymaster/v3/sepolia/APY_KEY
  1. Create a empty file and a function to run our script
index.ts
async function main(): Promise<void> {
  // Rest of the code will go here...
}

main();

Step 2: Generate Account Address​

To generate an account address, we will be using Simple7702Account, a fully audited minimalist smart contract account that can be safely authorized by any EOA. It adds full support for major smart account features like batching and gas sponsorship.

index.ts
import { Simple7702Account } from "abstractionkit";
import { Wallet } from "ethers";

const eoaDelegator = Wallet.createRandom();

const smartAccount = new Simple7702Account(eoaDelegator.address);

console.log("Account address(sender) : " + smartAccount.accountAddress);

Let's run this code

Terminal
npx ts-node index.ts

If everything worked, you will get the calculate address of the smart account in the console.

Details

Result example Account address(sender): 0x32afdcfa1e3bfe70d03ecb55b5c8045c26515c9d

Step 3: Generate callData for minting NFTs​

Not only we can upgrade the EOA to a smart account, we will also be demonstrating how to execute minting two NFTs, all in the same transaction.

index.ts
import {
  MetaTransaction,
  getFunctionSelector,
  createCallData,
} from "abstractionkit";

// We will be mitting two random NFTs in a single tx
const nftContractAddress = "0x9a7af758aE5d7B6aAE84fe4C5Ba67c041dFE5336";
const mintFunctionSignature = 'mint(address)';
const mintFunctionSelector = getFunctionSelector(mintFunctionSignature);
const mintTransactionCallData = createCallData(
    mintFunctionSelector,
    ["address"],
    [smartAccount.accountAddress]
);
const transaction1: MetaTransaction = {
    to: nftContractAddress,
    value: 0n,
    data: mintTransactionCallData,
}

const transaction2: MetaTransaction = {
    to: nftContractAddress,
    value: 0n,
    data: mintTransactionCallData,
}

Step 3: Create UserOperation​

Now the fun part. Call createUserOperation, which will:

  1. Compute the r and s values for the eip7702Auth. These values are part of signature authorization tuple needed to upgrade the EOA. This is only used once, during the upgrade transaction of the EOA.
  2. Determine the nonce and fetch the gas prices from the provided node rpc
  3. Estimate gas limits from the provided bundler

This returns a unsigned user operation. Use calculateUserOperationMaxGasCost to calculate its cost.

index.ts
import {
  ...
  calculateUserOperationMaxGasCost
} from "abstractionkit";

const bundlerUrl = process.env.BUNDLER_URL as string;
const chainId = BigInt(process.env.CHAIN_ID as string);
const eoaDelegatorPrivateKey = process.env.PRIVATE_KEY as string;

let userOperation = await smartAccount.createUserOperation(
    [transaction1, transaction2],
    jsonRpcNodeProvider,
    bundlerUrl,
    {
        eip7702Auth:{
            chainId, // chainId at which the account will be upgraded
        }
    }
);

const cost = calculateUserOperationMaxGasCost(userOperation)
console.log("This useroperation may cost upto : " + cost + " wei")
console.log("Please fund the sender account : " + userOperation.sender +" with more than " + cost + " wei")

Step 4: Sign the Delegate Authorization​

Sign the eip7702Auth tuple to delegate the authorization to the smart account. Again, this is only called once, during the upgrade transaction of the EOA.

userOperation.eip7702Auth = createAndSignEip7702DelegationAuthorization(
    BigInt(userOperation.eip7702Auth.chainId),
    userOperation.eip7702Auth.address,
    BigInt(userOperation.eip7702Auth.nonce),
    eoaDelegatorPrivateKey
)

Step 5: Get Paymaster data​

Optionally sponsor gas for your user transaction or offer them to pay gas in erc-20 tokens

import { CandidePaymaster } from "abstractionkit";

const paymasterUrl = process.env.PAYMASTER_URL as string;

const paymaster = new CandidePaymaster(paymasterUrl)

let [paymasterUserOperation, _sponsorMetadata] = await paymaster.createSponsorPaymasterUserOperation(
    userOperation, 
    bundlerUrl, 
);

userOperation = paymasterUserOperation;

Step 6: Sign and Submit​

  1. Call signUserOperation, which will create a signature for the private key provided of the owner of the EOA.
index.ts
const privateKey = process.env.PRIVATE_KEY as string;

userOperation.signature = smartAccount.signUserOperation(
    userOperation,
    eoaDelegator.privateKey,
    chainId,
);
  1. Use the Bundler URL to send the userop to the bundler with sendUserOperation, and await the return SendUseroperationResponse object to confirm the on-chain inclusion of the user operation.
index.ts
const sendUserOperationResponse = await smartAccount.sendUserOperation(userOperation, bundlerUrl)

console.log("UserOperation sent. Waiting to be included ......")
  1. Track the userOperation and wait for its inclusion onchain
let userOperationReceiptResult = await sendUserOperationResponse.included()

console.log("Useroperation receipt received.")
console.log(userOperationReceiptResult)

if (userOperationReceiptResult.success) {
    console.log("EOA upgraded to a Smart Account and minted two Nfts! The transaction hash is : " + userOperationReceiptResult.receipt.transactionHash)
} else {
    console.log("Useroperation execution failed")
}

Now let's run this code again

Terminal
npx ts-node index.ts

You've now sent upgrade your EOA to a Smart Account! If everything went well, you should see the bundler returning a user operation receipt

Result
Useroperation sent. Waiting to be included ......
Useroperation receipt received.
{
  userOpHash: '0x89a5111d40c4ca45977a28419a08ca33e496a88e973bc995ec6a5a28da564cb5',
  entryPoint: '0x4337084D9E255Ff0702461CF8895CE9E3b5Ff108',
  sender: '0xbdbc5fbc9ca8c3f514d073ec3de840ac84fc6d31',
  nonce: 0n,
  paymaster: '0x0000000000000000000000000000000000000000',
  actualGasCost: 243581295447n,
  actualGasUsed: 84429n,
  success: true,
  logs: '[{"address":"0x4337084D9E255Ff0702461CF8895CE9E3b5Ff108","topics":["0x49628fd1471006c1482da88028e9ce4dbb080b815c9b0344d39e5a8e6ec1419f","0x89a5111d40c4ca45977a28419a08ca33e496a88e973bc995ec6a5a28da564cb5","0x000000000000000000000000bdbc5fbc9ca8c3f514d073ec3de840ac84fc6d31","0x0000000000000000000000000000000000000000000000000000000000000000"],"data":"0x0000000000000000000000000000000000000000000000000000000000000015000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000038b6939b5700000000000000000000000000000000000000000000000000000000000149cd","blockHash":"0x51e49209271f31b831f466c256e971053f8d65fb71160a6da36277b56270a74c","blockNumber":"0x347611","blockTimestamp":"0x67c57b18","transactionHash":"0x763dc353dee853da059b9e8c4b9997cccd4597b4cfcfc5fc3133dcffc778d93a","transactionIndex":"0x8","logIndex":"0x3e","removed":false}]',
  receipt: {
    blockHash: '0x51e49209271f31b831f466c256e971053f8d65fb71160a6da36277b56270a74c',
    blockNumber: 3438097n,
    from: '0x6eb0296e64fb8d9d946c7b819e4ff55c7167b0ce',
    cumulativeGasUsed: 884430n,
    gasUsed: 96887n,
    logs: '[{"address":"0x4337084D9E255Ff0702461CF8895CE9E3b5Ff108","topics":["0x2da466a7b24304f47e87fa2e1e5a81b9831ce54fec19055ce277ca2f39ba42c4","0x000000000000000000000000bdbc5fbc9ca8c3f514d073ec3de840ac84fc6d31"],"data":"0x000000000000000000000000000000000000000000000000000000627c080142","blockHash":"0x51e49209271f31b831f466c256e971053f8d65fb71160a6da36277b56270a74c","blockNumber":"0x347611","blockTimestamp":"0x67c57b18","transactionHash":"0x763dc353dee853da059b9e8c4b9997cccd4597b4cfcfc5fc3133dcffc778d93a","transactionIndex":"0x8","logIndex":"0x3c","removed":false},{"address":"0x0000000071727de22e5e9d8baf0edac6f37da032","topics":["0xbb47ee3e183a558b1a2ff0874b079f3fc5478b7454eacf2bfc5af2ff5878f972"],"data":"0x","blockHash":"0x51e49209271f31b831f466c256e971053f8d65fb71160a6da36277b56270a74c","blockNumber":"0x347611","blockTimestamp":"0x67c57b18","transactionHash":"0x763dc353dee853da059b9e8c4b9997cccd4597b4cfcfc5fc3133dcffc778d93a","transactionIndex":"0x8","logIndex":"0x3d","removed":false},{"address":"0x0000000071727de22e5e9d8baf0edac6f37da032","topics":["0x49628fd1471006c1482da88028e9ce4dbb080b815c9b0344d39e5a8e6ec1419f","0x89a5111d40c4ca45977a28419a08ca33e496a88e973bc995ec6a5a28da564cb5","0x000000000000000000000000bdbc5fbc9ca8c3f514d073ec3de840ac84fc6d31","0x0000000000000000000000000000000000000000000000000000000000000000"],"data":"0x0000000000000000000000000000000000000000000000000000000000000015000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000038b6939b5700000000000000000000000000000000000000000000000000000000000149cd","blockHash":"0x51e49209271f31b831f466c256e971053f8d65fb71160a6da36277b56270a74c","blockNumber":"0x347611","blockTimestamp":"0x67c57b18","transactionHash":"0x763dc353dee853da059b9e8c4b9997cccd4597b4cfcfc5fc3133dcffc778d93a","transactionIndex":"0x8","logIndex":"0x3e","removed":false}]',
    logsBloom: '0x00000000000000000000000000000400000000000000000000000000000000000008000000000000000800010000000000000000000000000000020000000000000000000000000000000000000000000040000000000000000000000000200000000000020801000000000000000800000000000000000000000000000200000000000000000000000000000000000000000000000000008000000000000000000000000000000000400000000800000000000000000000000002000000000000000000000000410001000000000000000000000000000000000000000020000040000000000000000000000000000000000000000000000000000000000000',
    transactionHash: '0x763dc353dee853da059b9e8c4b9997cccd4597b4cfcfc5fc3133dcffc778d93a',
    transactionIndex: 8n,
    effectiveGasPrice: 2644614n
  }
}
EOA upgraded to a Smart Account and minted two Nfts! The transaction hash is : 0x763dc353dee853da059b9e8c4b9997cccd4597b4cfcfc5fc3133dcffc778d93a

You can lookup the hash on explorers that supports user operations like Blockscout.

Full Example​

Below is the complete example code that you can copy directly to implement the functionality described in the tutorial.

index.js
import * as dotenv from 'dotenv'
import {
    Simple7702Account,
    getFunctionSelector,
    createCallData,
    createAndSignEip7702DelegationAuthorization,
    CandidePaymaster,
} from "abstractionkit";
import { Wallet } from 'ethers';

async function main(): Promise<void> {
    //get values from .env
    dotenv.config()
    const chainId = BigInt(process.env.CHAIN_ID as string)
    const bundlerUrl = process.env.BUNDLER_URL as string
    const jsonRpcNodeProvider = process.env.JSON_RPC_NODE_PROVIDER as string;
    
    const eoaDelegator = Wallet.createRandom();
    const eoaDelegatorPublicAddress = eoaDelegator.address;
    const eoaDelegatorPrivateKey = eoaDelegator.privateKey;
    const paymasterUrl = process.env.PAYMASTER_URL as string;


    // initiate the smart account
    const smartAccount = new Simple7702Account(eoaDelegatorPublicAddress);

    // We will be mitting two random NFTs in a single txs
    const nftContractAddress = "0x9a7af758aE5d7B6aAE84fe4C5Ba67c041dFE5336";
    const mintFunctionSignature = 'mint(address)';
    const mintFunctionSelector = getFunctionSelector(mintFunctionSignature);
    const mintTransactionCallData = createCallData(
        mintFunctionSelector,
        ["address"],
        [smartAccount.accountAddress]
    );
    const transaction1 = {
        to: nftContractAddress,
        value: 0n,
        data: mintTransactionCallData,
    }

    const transaction2 = {
        to: nftContractAddress,
        value: 0n,
        data: mintTransactionCallData,
    }

    let userOperation = await smartAccount.createUserOperation(
        [
            //You can batch multiple transactions to be executed in one useroperation.
            transaction1, transaction2,
        ],
        jsonRpcNodeProvider, //the node rpc is used to fetch the current nonce and fetch gas prices.
        bundlerUrl, //the bundler rpc is used to estimate the gas limits.
        {
            eip7702Auth:{
                chainId: chainId, // chainId at which the account will be upgraded
            }
        }
    );
    
    userOperation.eip7702Auth = createAndSignEip7702DelegationAuthorization(
        BigInt(userOperation.eip7702Auth.chainId),
        userOperation.eip7702Auth.address,
        BigInt(userOperation.eip7702Auth.nonce),
        eoaDelegatorPrivateKey
    )

    
    let paymaster: CandidePaymaster = new CandidePaymaster(
        paymasterUrl
    )

    let [paymasterUserOperation, _sponsorMetadata] = await paymaster.createSponsorPaymasterUserOperation(
        userOperation, bundlerUrl) // sponsorshipPolicyId will have no effect if empty
    userOperation = paymasterUserOperation; 

    userOperation.signature = smartAccount.signUserOperation(
        userOperation,
        eoaDelegatorPrivateKey,
        chainId,
    );
    
    let sendUserOperationResponse = await smartAccount.sendUserOperation(
        userOperation, bundlerUrl
    );

    console.log("userOperation: ", userOperation)
    console.log("userOp sent! Waiting for inclusion...");
    console.log("userOp Hash: ", sendUserOperationResponse.userOperationHash);

    let userOperationReceiptResult = await sendUserOperationResponse.included();

    console.log("Useroperation receipt received.")
    console.log(userOperationReceiptResult)
    if (userOperationReceiptResult.success) {
        console.log("EOA upgraded to a Smart Account and minted two Nfts! The transaction hash is : " + userOperationReceiptResult.receipt.transactionHash)
    } else {
        console.log("Useroperation execution failed")
    }
}

main()
Last updated on by sednaoui