The Ethereum Foundation announced on October 1 that zkAPI, an AI payment system co-designed by Vitalik Buterin, is now live on the Ethereum mainnet. The system allows users to retrieve unused funds via an on-chain withdrawal path without server permission if the API service is interrupted. However, users' recovery capability depends on their held spending state, whether the vault is paused, and the validity period of the tickets. The mainnet configuration specifies a challenge period of 24 hours and a ticket lifecycle of 30 days. zkAPI's vaults currently hold deposits denominated in Ethereum (ETH).