Ethereum's New zkAPI Tool: Private Payments for AI Services

The Ethereum Foundation has launched zkAPI on mainnet, allowing users to pay for AI services without linking their requests to their wallet. This system was built in collaboration with the Open Anonymity Project and is designed to provide a more private payment experience.

To use zkAPI, users first deposit tokens into a vault contract on Ethereum, which records the deposit as a private note without revealing ownership information.

When making a request, the user's device creates a zero-knowledge proof that shows they have sufficient funds without revealing which deposit is theirs. A zkAPI server checks this proof and issues a temporary API key with a spending limit attached.

The system has real limits, as it does not hide network metadata or IP addresses, allowing some tracking to still be possible. However, the Ethereum Foundation lists several potential uses for zkAPI beyond AI chat, including blockchain data queries and payments between AI agents.