Account Abstraction

• Account Abstraction (AA) is a concept in Ethereum that enhances user experience by allowing smart contracts to act as user accounts(EOAs)

• This removes the traditional process of EOAs for initiating transactions!!!

• Account Abstraction modifies the traditional Ethereum account model by introducing smart contract wallets that can act like EOAs

• AA improves

What is ERC-4337?

ERC-4337 is a specification that aims to use an entry point contract to achieve account abstraction without changing the consensus layer protocol of Ethereum.

• Instead of modifying the logic of the consensus layer itself, ERC-4337 replicates the functionality of the transaction mempool in a higher-level system

• ERC-4337 also introduces paymaster mechanism -> Other users can pay the gas fees for the transaction in ERC-20 tokens

There are several main components to ERC-4337 :-

1. UserOperation:

   • This are transaction objects that are used to execute transactions with contract accounts.
   • UserOp struct contains ->> sender address, nonce, bytes functionData, signature...
   • sender -> address of the smart contract account
   • functionData -> Data that's passed to the sender for execution (function selector!!!)

2. UserOperation mempool(Bundlers):

   • UserOperations will be sent to the UserOperation mempool
   • Bundlers listen to the UserOperation mempool and bundle multiple UserOperations together into a "classic" transaction.

3. Bundlers Service:

   • These are specialized nodes that collect UserOperations from multiple users and package them into a single Ethereum block for efficiency
   • A bundler is the core infrastructure component that allows account abstraction to work on any EVM network
   • This work with a new mempool of UserOperations and get the transaction included on-chain.
   • This package UserOperations from a mempool and send them to the EntryPoint contract on-chain

4. Paymasters contracts:

   • This are smart contract accounts that can pays the gas fees for Account Contracts
   • Users can also pay in ERC-20 tokens instead of ETH
   • Paymasters are included -> because the wallet owner needs to find a way to get some ETH before interaction with DApps on-chain
   • With paymasters, ERC-4337 allows abstracting gas payments altogether, meaning ​​someone other than the wallet owner can pay for the gas instead.
   • This makes user experience better!!!

5. Entry point contract:

   • This contract verifies and executes the bundles of UserOperations sent to it from bundlers!!!
   • The use of a single EntryPoint contract simplifies the logic used by smart contract wallets
   • Bundlers will send many userOps to entrypoint contract
   • This will verify each userOps with contract accounts
   • After verification -> EntryPoint contract will asks contract account to execute the specific function

6. Smart contract Account:

   • An smart contract wallet of user
   • This contract account should consist two functions -> validateUserOps and executeUserOps
   • one to verify signatures, and another to process transactions.

7. Aggregrator(optinal)

Account Abstraction Flow!!!

1. AA user -> Bundlers

   • AA user will signed userOp (where sender will be contract account)
   • Bundlers will collect many userOps
   • Verifies the userOps -> Sign them in a TNX -> Send it off to the entryPoint contract

2. Bundlers will simulate each userOps:

   • Bundlers after collecting all userOps -> Send that to the entrypoint contract for simulating and verifying each userOps with contract account and paymasters
   • EntryPoint contract will verifies each userOps on-chain with contract account

3. Bundlers will submit TNX to entry point contract:

   • Entrypoint will checks for verified userOps with contract account
   • Paymasters will verify the userOps
   • After verification -> Contract account executes the function and perform the state changes!!!

Sources

1. Account abstraction github repo!!!

   • https://github.com/eth-infinitism/account-abstraction
   • https://github.com/stackup-wallet

2. Blogs and articles for AA

   • https://www.erc4337.io/docs
   • https://www.cyfrin.io/blog/what-is-blockchain-account-abstraction-a-5-minute-guide
   • https://eips.ethereum.org/EIPS/eip-4337
   • https://ethereum.org/en/roadmap/account-abstraction/

3. Blog to create AA from Scratch!!!

   • https://www.alchemy.com/blog/account-abstraction