weth-paymaster

This repository is a sample implementation of WETHPaymaster, a trustless Paymaster built on top of ERC-4337: Account Abstraction Using Alt Mempool.

Features

Just like with Wrapped Ether, 1 ETH is always equal to 1 WETHP, deposited/withdrawn without relying in any oracles
Unlike Wrapped Ether, it can pay for your AA User Operations
Unlike the default Paymaster implementations, it is completely trustless

Motivations

The default BasePaymaster, VerifyingPaymaster and TokenPaymaster implementations all assume a trusted owner, which can impose security issues for users. In addition, using a ERC-20 tokens to pay for transactions, such as USDC, also introduces a security risks related to price oracles, liquidity conditions, and speed of operational controls in case of extreme events.

WETHPaymaster aims to eliminate this reliance on a trusted parties by providing a secure solution for ERC-4337 accounts.

How to use

deposit ETH and mint WETHP
transfer WETHP to your ERC-4337 account
use WETHP to pay for your UserOperations

Considerations

There is no owner associated with WETHPaymaster. As a result, it is necessary to first addStake to the EntryPoint so that the Paymaster can be accepted in the system as per the EIP-4337 requirements. This stake will be permanently locked in the EntryPoint, as there is no mechanism to differentiate between users who staked from the EntryPoint's perspective.
WETHPaymaster does not support first-time account creation since it does not assume any trusted factory contract.

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