Account Abstraction

Account abstraction is a term commonly used to address the use of smart contract wallets. These smart contract wallets are based on the ERC-4337 which aims at improving the user onboarding journey and enabling more sophisticated transaction patterns by abstracting details like validation, gas payment, and execution from the user.

Web3Auth's Native Account Abstraction

Effortlessly create and manage smart accounts for your users with just a few lines of code, using our native account abstraction. Additionally, SCWs offer enhanced control and programmability, enabling features like those listed below.

• Gas Abstraction: Cover transaction fees for users, or allow users to pay for their own transactions using ERC-20 tokens.
• Batch Transactions: Perform multiple transactions in a single call.
• Automated Transactions: Allow users to automate actions, like swapping ETH to USDT when ETH hits $4,000.
• Set Spending Limits: Allow users to set tailored spending limits.

Our native AA integration streamlines your setup, allowing you to create and manage smart accounts using your favorite libraries like Viem, Ethers, and Web3.js. With this, you don't need to rely on third party packages to effortlessly create ERC-4337 compatible Smart Contract Wallets (SCWs), and give users the ability to perform batch transactions and efficiently manage gas sponsorship.

Web3Auth's native account abstraction gives you the flexibility to choose your preferred account abstraction provider, configure your bundler client, and integrate your paymaster. Please checkout our documentation on how ERC-4337 components work for more information.

Getting Started

Web3Auth's native account abstraction gives you the flexibility to choose your preferred account abstraction provider, configure your bundler client, and integrate your paymaster. Learn how to use Web3Auth with Account Abstraction.

Components of ERC 4337

Smart contract wallets did exist before ERC 4337 but lacked a standardization across the ecosystem which reduced the interoperability. ERC 4337 helps to standardize account abstraction across all the Ethereum compatible chains. ERC 4337 consists of a few main components which help us achieve account abstraction.

UserOperation

A UserOperation is the transaction object for the smart contract wallets, and was introduced to avoid the changes on the EVM. Unlike EOA wallets, where the user signs the transaction, in smart contract wallets, the user signs a UserOperation.

UserOperation Structure

Field	Type	Description
sender	address	The address of the sender smart account
nonce	uint256	Anti-replay parameter
factory	address	Contract address for the Factory contract used to deploy new account, if not deployed.
factoryData	bytes	Data to be used during deploying the new account through Factory.
callData	bytes	The data to pass to the smart account during the main execution phase
callGasLimit	uint256	The amount of gas to allocate the main execution call
verificationGasLimit	uint256	The amount of gas to allocate for the verification step
preVerificationGas	uint256	Extra gas to pay the bundler
maxFeePerGas	uint256	Maximum fee per gas (see EIP-1559)
maxPriorityFeePerGas	uint256	Maximum priority fee per gas (see EIP-1559)
paymaster	address	Address of paymaster contract. Should be empty if account is paying for the fees itself.
paymasterVerificationGasLimit	uint256	The amount of gas to allocate for the paymaster validation code.
paymasterPostOpGasLimit	uint256	The amount of gas to allocate for the paymaster post-operation code.
paymasterData	bytes	Data for paymaster, only if the paymaster is used
signature	bytes	Data passed into the account to verify authorization

UserOp Mempool

Mempools for User Operation are separate from the regular blockchain transaction mempool.ERC 4337 introduces an alternative to the mempool, called UserOp Mempool, which helps to keep track of pending UserOperations. It acts as a waiting room and helps bundlers to keep track of UserOperations.

Bundler

Unlike the RPC nodes responsible for validating the transactions and submitting them to the blockchain, bundlers are third party nodes that bundles the UserOperations, perform the validation, and runs the simulations before submitting them on-chain.

The bundler is also responsible to validate that the Paymaster has enough balance to sponsor the gas fees for the batch transactions. For aggregated UserOperations, the bundler also ensures that the aggregated signature is created, and the UserOperations are updated with the same. The aggregated signatures are used to improve the efficiency and scalability of transaction processing by bundler.

EntryPoint

The EntryPoint contract, as its name suggests, serves as the global singleton that manages UserOperations by validating and executing them. When a UserOperation is submitted, the EntryPoint performs the following key tasks:

• If the UserOperations are bundled into a single transaction, the EntryPoint validates the aggregated signature to ensure its validity.

• The EntryPoint checks if the user's account is already deployed. If it isn't, the contract deploys the account using the CREATE2Factory. Afterwards, the EntryPoint uses the Account contract to validate the UserOperation.

• If a Paymaster is involved in the UserOperation, the EntryPoint verifies that the Paymaster has agreed to cover the transaction fees by validating its signature. If no Paymaster is used, the EntryPoint ensures that the user has sufficient balance to pay for the gas fees.

• After successfully validating the UserOperation and Paymaster details, the EntryPoint proceeds to execute the transaction.

Smart Account

Smart accounts are user facing accounts deployed through the CREATE2Factory. Each smart account contains a key function called validateUserOp, which validates the UserOperation. This function is triggered by the EntryPoint contract during the operation validation phase.

Beyond basic functionality, smart accounts can incorporate advanced features like account recovery, autopilot execution, spend limits, and other customizable, programmable capabilities.

Paymaster

The paymaster component of the ERC 4337 is responsible for sponsoring the gas fees for the UserOperations. The paymaster contract also allows the user to pay the gas fees with the supported ERC-20 tokens.

The paymaster contract must implement the validatePaymasterUserOp function which is called by the EntryPoint contract during the validation phase. The paymaster also has additional postOp function which is called by the EntryPoint contract after the transaction is executed. This function handles the additional logic required by the paymaster. For instance, withdraw the ERC-20 token from the user's account after the transaction is executed.

Aggregator

As the name suggests, the aggregator contract is responsible for aggregating the signatures of the UserOperations. The aggregator contract must implement the aggregateSignatures function which takes in a list of signatures and returns the aggregated signature. The signatues are usually aggregated by the bundler to improve the efficiency and scalability of transaction processing, as it allows bundler to submit multiple UserOperations in a single transaction.

For validating the aggregated signature, the Aggregator also has the validateSignatures function used by the EntryPoint contract during the validation phase.