Ethereum Foundation and Open Anonymity launch zkAPI for private AI access

The Ethereum Foundation and the Open Anonymity Project have launched zkAPI, a system on Ethereum mainnet that lets people pay for API access without leaving a trail back to who they are. The launch went live on October 1, 2026. The setup centers on a smart contract vault deployed on Ethereum mainnet. Users deposit ETH or USDC into that vault. Those deposits become credits, and the vault contract holds them as USDC credits. When a user wants to call an API, such as an AI model, they generate a cryptographic proof authorizing the payment. The service gets paid, and the user gets their response. The authorization is designed to be unlinkable to any specific deposit or identity. Under the hood, zkAPI relies on three cryptographic building blocks: Groth16 proofs: a type of zero-knowledge proof that lets someone prove a statement is true without revealing the underlying data. Baby-JubJub commitments: a way of locking in a value, like a deposit, so it can be referenced later without being exposed. A 32-level Merkle tree: a data structure that bundles many commitments into a single fingerprint, which a user can prove membership in without pointing to their specific entry. User funds sit in...