What Is the Role of a ‘Keeper’ in a DeFi Liquidation Process?

A 'keeper' is an external, often automated, entity (a bot or a user) that monitors the blockchain for undercollateralized positions that meet the criteria for liquidation. The keeper is incentivized to execute the liquidation transaction by a fee or a discount on the collateral they purchase.

They are not part of the core smart contract but are essential actors who ensure the financial health of the protocol by triggering the necessary liquidation function when market conditions demand it.