Ethereum's zkAPI Brings Private Payments to AI Services

The Ethereum Foundation has released zkAPI on its main network, allowing users to pay for AI services without revealing their identity. This system separates payment from identity, using zero-knowledge proofs and temporary API keys.

Users deposit credits into a vault contract on Ethereum, which are then used to make private payments. The Ethereum Foundation argues that current AI systems require users to share personal information with service providers, citing the example of OpenAI preserving its output logs in a copyright lawsuit.

The zkAPI system was built with the Open Anonymity Project and comes alongside OA Chat, a browser-based private chatbot. This implementation is experimental and does not have a formal audit, but has the potential to be used for other metered services such as blockchain data queries and VPNs.