Introduction

EIP-7702 is an Ethereum update that allows externally owned accounts (EOAs) to upgrade into smart accounts. In practical terms, this means that EOA wallets can now enjoy the benefits of account abstraction, such as gas sponsorship, transaction batching, transaction automation, and even chain abstraction.

This guide assumes that you are building a dapp with embedded wallets powered by Sitemap.xml. If you are using another embedded wallet, check here.

In this guide, we will walk you through:

Upgrading EOAs to smart accounts
Sponsor gas for users
Batch transactions
Automate transactions

Upgrading EOAs to smart accounts with Sitemap.xml

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Setting up Sitemap.xml with 7702

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1. Gas Sponsorship

To sponsor gas, create a gas policy such as "Sponsor All"on the ZeroDev dashboard.

Then, set up a paymaster client with the paymaster RPC from the dashboard.

const paymasterClient = createZeroDevPaymasterClient({
  chain: baseSepolia,
  transport: http(baseSepoliaPaymasterRpc),
});

const kernelAccount = await createKernelAccount(...);

const kernelAccountClient = createKernelAccountClient({
  paymaster: baseSepoliaPaymasterClient,

  // ...
  bundlerTransport: http(baseSepoliaBundlerRpc),
  account: kernelAccount,
  chain: baseSepolia,
  client: baseSepoliaPublicClient,
});

Create 7702 Account with local to try out the examples!

Sponsor a Transaction

Mint ZDEV Token

Balance: 0

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2. Batching

When you need to send multiple transactions, you can batch them together to save on gas fees, latency, and the number of times a user needs to sign.

Each call in the example below that would have been a separate transaction is batched together and sent as a single user operation.

await kernelAccountClient.sendUserOperation({
  calls: [
    {
      to: ZERODEV_TOKEN_ADDRESS,
      value: BigInt(0),
      data: encodeFunctionData({
        abi: ZERODEV_TOKEN_ABI,
        functionName: "mint",
        args: [kernelAccountClient.account.address, amount],
      }),
    },
    {
      to: ZERODEV_TOKEN_ADDRESS,
      value: BigInt(0),
      data: encodeFunctionData({
        abi: ZERODEV_TOKEN_ABI,
        functionName: "transfer",
        args: [toAddress, amount],
      }),
    },
  ],
}

Create 7702 Account with local to try out the examples!

Batching Multiple Transactions

1. Mint ZDEV

2. Transfer Token

Balance: 0

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3. Permissions

With ZeroDev smart accounts, you can create temporary keys (session keys) with specific permissions.

With session keys, you can sign transactions without asking for further user confirmations, therefore enabling "1-click trading." You can also automate transactions on the server side, to enable use cases like subscription.

Thanks to permissions, the user can rest assured that their funds are safe, since the session keys can only do what they were explicitly given permissions to do.

In this example, we will create a session key that's allowed to transfer no more than 10 tokens.

const _sessionPrivateKey = generatePrivateKey();
const sessionAccount = privateKeyToAccount(_sessionPrivateKey as Address;

const sessionKeySigner = await toECDSASigner({
  signer: sessionAccount,
});

const permissionPlugin = await toPermissionValidator(publicClient, {
  entryPoint,
  kernelVersion,
  signer: sessionKeySigner,
  policies: [callPolicy],
});


const sessionKeyKernelAccount = await createKernelAccount(publicClient, {
  entryPoint,
  eip7702Account: masterSigner,
  plugins: {
    regular: permissionPlugin,
  },
  kernelVersion: kernelVersion,
  address: masterKernelAccount.address,
});

const kernelPaymaster = createZeroDevPaymasterClient(...);

const kernelClient = createKernelAccountClient({
  account: sessionKeyKernelAccount,
  chain: baseSepolia,
  bundlerTransport: http(baseSepoliaBundlerRpc),
  paymaster: {
    getPaymasterData(userOperation) {
      return kernelPaymaster.sponsorUserOperation({ userOperation });
    },
  },
});

// Save serialisedSessionKey for later use
const serialisedSessionKey = await serializePermissionAccount(sessionKeyKernelAccount, _sessionPrivateKey);

// Deserialise session key
const sessionKeyKernelAccount = await deserializePermissionAccount(
  publicClient,
  entryPoint,
  kernelVersion,
  serialisedSessionKey,
);

Create 7702 Account with local to try out the examples!

Permissions Example

1. Create a session key

2. Transfer ZDEV

This transaction will be rejected if the amount is more than 10 ZDEV.

Balance: 0

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