ERC-4337

What is ERC-4337?

ERC-4337 is an Ethereum standard that enables account abstraction at the application layer without requiring changes to the core Ethereum protocol. Published in March 2023, it introduces a system of UserOperations, bundlers, and an EntryPoint contract that together allow smart contract wallets to function as first-class accounts with full transaction flexibility.

The genius of ERC-4337 is achieving account abstraction without a hard fork. By implementing the entire system through smart contracts and an alternative mempool, it provides immediate benefits while remaining forward-compatible with potential future protocol-level account abstraction.

How it Works

ERC-4337 defines a complete account abstraction infrastructure:

• A pseudo-transaction object containing user intent
• Includes sender (wallet), calldata, gas limits, and signatures
• Signed according to wallet's custom validation logic
• Submitted to a separate UserOp mempool

• A node that monitors the UserOp mempool
• Aggregates multiple UserOps into a single transaction
• Submits bundle to the EntryPoint contract
• Earns fees from successful execution

• Singleton contract deployed on each chain
• Receives bundles from bundlers
• Calls each wallet's validateUserOp function
• Executes operations that pass validation
• Handles gas accounting and refunds

• Smart contract implementing IAccount interface
• Custom validateUserOp for signature verification
• Any validation logic: multisig, social, biometric
• Executes arbitrary calls after validation

• Contract that sponsors gas for users
• Can charge users in different tokens
• Enables gasless transactions for end users
• dApps use paymasters for better UX

Practical Example

You install a wallet app supporting ERC-4337 and create an account secured by your phone's biometric authentication. To mint an NFT, you tap confirm on your phone. The wallet creates a UserOperation signed with your biometric key. A bundler picks it up from the mempool, bundles it with other UserOps, and submits to the EntryPoint. The NFT project's paymaster covers your gas, so you pay nothing. The EntryPoint verifies your wallet contract approves the operation, then executes the mint.

Why it Matters

ERC-4337 is transformative for Ethereum's usability:

• Works today without protocol changes
• Already deployed on mainnet and major L2s
• Growing ecosystem of wallets and tools

• Common interface across all AA wallets
• Interoperable bundler network
• Shared infrastructure reduces costs

• Coinbase Wallet using AA for smart accounts
• Safe integrating ERC-4337 compatibility
• Major L2s supporting native AA

• Foundation for protocol-level AA improvements
• RIP-7560 proposes native support building on 4337
• Investment in 4337 infrastructure carries forward

ERC-4337 represents pragmatic innovation, delivering account abstraction benefits today while the community works on longer-term protocol improvements.