# Gas Modes

# How does Auto gas mode works?

If you have 0.4 Ether as MAX_COST, and monitor picks up a listing for 0.0247 Ether for example, this special gas mode is going to add the difference in gas.

It's really suggested to use this mode with Flashbots, to avoid expensive fails.

This mode really comes in clutch if someone lists something by mistake for cheap. For other gas modes, please refer to GAS_MODE.