Practical Guide to ERC-4337 Account Abstraction Implementation

While most online articles about ERC-4337 offer introductory explanations, hands-on implementation guides are scarce. This article bridges that gap by providing actionable steps for deploying and interacting with Account Abstraction (AA) smart contracts.

Prerequisites

Contract Deployment

1. EntryPoint Contract: Use the latest EntryPoint address from Infinitism’s Discord.

2. VerifyingPaymaster:

   • Deploy using multisol:

     cd account-abstraction
     multisol contracts/samples/VerifyingPaymaster.sol

   • Connect Remix to the generated multisol-verifyingpaymaster directory via remixd.
   • Deploy with MetaMask, passing the EntryPoint address and verifyingSigner account.

3. Other Contracts:

   • SimpleAccountFactory: Deploys AA instances.
   • TestToken: ERC-20 contract for minting tokens.

Contract Verification

Upload all .sol files from the multisol-verifyingpaymaster directory via Etherscan’s "Solidity (Multi-Part files)" option.

Staking and ETH Deposit

• Call addStake and depositTo for the paymaster via Etherscan, referencing sample transactions.

Key Addresses

• EntryPoint: 0x0F46c65C17AA6b4102046935F33301f0510B163A
• VerifyingPaymaster: 0xE0165B20422B0dC3802085D34013bA0E2a83f640

Bundler Setup

Use a local stackup-bundler for logging:

• Ensure the bundler’s account holds sufficient ETH for gas fees.
• Nodes must support debug_traceCall (e.g., Goerli RPC).

Commands

Run using config.json:

ETH Transfer

yarn run simpleAccount transfer --to 0x413978328AA912d3fc63929d356d353F6e854Ee1 --amount 0.001

ERC-20 Transfer

yarn run simpleAccount erc20Transfer --token 0x61a89342F52d9F31626B56b64A83579E5c368f4c --to 0x413978328AA912d3fc63929d356d353F6e854Ee1 --amount 0.1

Paymaster Integration

Append --withPaymaster:

yarn run simpleAccount erc20Transfer --token 0x61a89342F52d9F31626B56b64A83579E5c368f4c --to 0x413978328AA912d3fc63929d356d353F6e854Ee1 --amount 0.1 --withPaymaster

Transaction Analysis

1. ETH Transfer: Bundler submits handleOps to EntryPoint, which routes funds and reimburses gas.
   👉 View ETH Transfer
2. ERC-20 Transfer: Similar flow, but for token transfers.
3. Paymaster ERC-20 Transfer: Gas fees deducted from paymaster’s ETH balance.

Gasless Chains Recommendation

For gasless transactions, leverage Godwoken’s built-in AA support, eliminating the need for a bundler.

FAQs

Q: Why is debug_traceCall required for bundlers?
A: It validates UserOperation simulations, ensuring only viable transactions are bundled.

Q: Can I use Infura/Alchemy as a bundler node?
A: No—they lack debug_traceCall support. Use Goerli RPC or a local geth full node.

Q: How does paymaster sponsorship work?
A: The paymaster’s ETH balance in EntryPoint covers gas fees, verified via verifyingSigner signatures.
👉 Explore Paymaster Options