/gasback

RIP-7767

Primary LanguageSolidity

Gasback

A barebones implementation of a gasback contract that implements RIP-7767.

Suggested setup for OP stack chains

Requirements

  • The baseFeeVault is deployed at 0x4200000000000000000000000000000000000019.
  • The WITHDRAWAL_NETWORK of the baseFeeVault is set to 1.

Via script

See script/Delegate7702.s.sol for an automated script that can help you deploy.

This script requires you to have the private key of the baseFeeVault recipient in your environment.

For more information on how to run a foundry script, see https://getfoundry.sh/guides/scripting-with-solidity.

Manual steps

  1. Deploy the gasback contract which will be used as an implementation via EIP-7702.

  2. Use EIP-7702 to make the EOA RECIPIENT of the baseFeeVault delegated to the gasback implementation.
    After delegating, use the EOA to call functions on itself to initialize the parameters:

    • setGasbackRatioNumerator(uint256)
      900000000000000000
    • setGasbackMaxBaseFee(uint256)
      115792089237316195423570985008687907853269984665640564039457584007913129639935
    • setBaseFeeVault(address)
      0x4200000000000000000000000000000000000019

  3. Put or leave some ETH into the EOA RECIPIENT, which will be the actual gasback contract. The ETH will act as a buffer that will be temporarily dished out to contracts calling the EOA RECIPIENT in the span of a single block. The base fees collected in a block will only be accrued into the baseFeeVault at the end of a block. Try not to empty ETH from the RECIPIENT when you are actually taking out ETH from it.

  4. For better discoverabiity (for the devX), deploy the gasbackBeacon and use the system address to set the EOA RECIPIENT.
    The exact CREATE2 instructions are in ./deployments.md.