Ethereum Foundation Launches zkAPI for Private AI Payments

Overview

• Ethereum and the Open Anonymity Project deployed the protocol to mainnet on Thursday, October 1, 2026, making the code and docs publicly available and labeled experimental.
• Users fund on-chain vaults with ETH or USDC and the client creates private notes that let a device prove available funds with zero-knowledge proofs without naming a specific deposit.
• A gateway that validates the proof issues a short-term API key with a spending limit so the user sends prompts directly to the AI provider while billing is handled separately.
• The design relies on Groth16 proofs, Baby-JubJub commitments and a 32-level Merkle tree but uses a trusted-setup whose published files do not prove the setup secret was destroyed, and notes can expire or be claimed by the treasury under current rules.
• The system does not hide prompt content or network metadata like IP addresses so users must add network-level privacy tools and client integrations plus clear UI warnings before they can rely on it for stronger anonymity.