Fiat Paymaster
Account Abstraction Paymaster that allows paying for gas fees with PayPal
Screenshots
Problem Statement
This project is an implementation of an account abstraction paymaster using the ERC-4337 paradigm that was recently deployed throughout the Ethereum ecosystem. Using a PayPal integration, we allow users to pay for any transaction fees with fiat.This paymaster is generic and can be used by any dapp or wallet by setting thepaymasterAndDatafield to the address of our paymaster.This project is cross-chain by nature, as it is deployed on many different chains that support AA:Optimism MainnetPolygon zkEVMGnosis ChainScrollGoerliYou can test it using our PayPal test account:email: sb-mx70425265463@personal.example.compassword: &$}0XzO4
Solution
We implemented aTokenPaymastercalled FPUSD (short for Fiat Paymaster USD). This paymasterisan ERC-20 token that is used to pay for ERC-4337 transactions, and represents an USD balance in PayPal.Since there aren't currently many ERC-4337 supporting wallets, we use the high-level@account-abstraction/sdkto create UserOperations and sign them in Metamask, which is later sent to a bundler to be included on the mempool.We spent some time doing a pull request to add token paymaster support to the trampoline wallet but this wallet was too unstable to complete it.