atlETH

atlETH serves as a wrapped representation of ETH within Atlas, enabling solvers to escrow funds for their gas consumption. Solvers pre committing to cover the gas costs for their respective operations allows bundlers to execute Atlas transactions that include multiple third party SolverOperations. It also discourages solver spam by leveraging the DoS protection inherent in the underlying chain's gas costs.

Verification of the solvers' atlETH balance is the responsibility of the OR and/or Atlas SDK. At the smart contract level, Atlas restricts solvers from participating in more than one auction per block to avoid double counting bonded atlETH across multiple applications and bundlers. Any attempt by solvers to execute a second operation in the same block results in a reverted operation, with solvers still incurring charges for their total gas costs. To engage in multiple intrablock Atlas auctions, solvers must use separate EOAs and maintain bonded atlETH balances in each.

In known bids mode the solver is responsible for approving payment for the sum of the following:

• The gas cost of the transaction so far, excluding costs attributed to reverted operations of other solvers.

• The gas cost remaining in the transaction up to the gas limit.

• The outstanding balance of any cross-operation flash loan initiated by the hooks.

In ex-post bids mode the exception to the above is that bundlers are responsible for the gas costs of the bid finding iteration.

A hold is placed on the solver’s bonded atlETH balance for the total owed, which is later decreased by the Atlas smart contract at the end of the transaction. Solvers may estimate the gas limit and value of the Atlas transaction before signing their operation. Solvers under attack by malicious originators, auctioneers, or bundlers will not be liable for their gas cost - an altered UserOperation or CallChainHash will attribute any accrued solver gas costs to the bundler.

To dis-incentivize bundlers from setting large gas limits, as that force solvers to maintain higher escrow balances, Atlas estimates the excess gas limit and charges the bundler for it during gas accounting.