The Ethereum Foundation and Open Anonymity Project announced the joint launch of zkAPI on October 1, stating that it is now operational on the Ethereum mainnet. Users can deposit ETH or USDC into a treasury contract once, and then authorize amounts using zero-knowledge proofs without revealing their payment identity to service providers.

The foundation's blog post was published by Vittorio Rivabella from the dAI team. The design corresponds to research published by Ethereum co-founder Vitalik Buterin and dAI head Davide Crapis on February 11. The mainnet contract records amounts as USDC credit, with the same set of tests deployed on Sepolia.

Service providers can see the request content but not the payer. The payment layer can only see the consumption amount and cannot link the amount to a specific request or user. On-chain records only include deposits, settlements, and withdrawals, without noting which service the funds were used for. User devices generate proofs indicating that a certain amount of funds is sufficient to cover the current consumption and has not been used previously. After off-chain verification by the server, a temporary key with a limit and validity period is issued.

Users can directly request service providers using this key. Service providers record actual usage and generate signed receipts, and the system deducts from the private balance according to actual usage. The proof uses Groth16, with a curve of BN254, and commitment and cancellation symbols using Poseidon hash, with the state stored in a 32-layer Merkle tree. The treasury is controlled by Ethereum contracts. If the server goes down, users can withdraw funds directly from the chain without server cooperation.

The first scenario is artificial intelligence inference. The foundation states that currently every API call carries identity, with keys pointing to accounts, and accounts pointing to payment methods, merging prompts into the same file. Health and finance-related prompts are therefore prioritized for separation. The same mechanism can also be used for blockchain RPC, image, and video generation interfaces that charge based on usage.

The buyer is a model user who does not want to link prompts and payment identity, while the seller is an API service provider that still charges based on usage. This is a settlement diversion driven by product launch, not a new token issuance. Beneficiaries are inference users seeking anonymous limits and service providers willing to connect to this treasury. Those under pressure are model platforms that price based on long-term account profiles and data merchants treating payment addresses as user identities.

Mainnet operation means that the treasury and proof process are available. The announcement did not specify how many model service providers are connected, the scale of deposits, or actual usage.

Source: Public Information