According to CoinMeta, zkapi, jointly developed by the Ethereum Foundation and an open anonymous project, is now running on the Ethereum mainnet. This project separates payments from identities through zero-knowledge proofs, allowing users to deposit assets such as ETH and USDC into a vault contract, and then authorize AI API to use those funds without revealing their identity. Service providers cannot know the identity of the payer, and payment service providers cannot link transactions to the users. The solution utilizes technologies such as groth16, bn254, poseidon, and merkle trees, enabling users to withdraw funds from the blockchain. It is suitable for scenarios involving AI inference, blockchain RPC, and pay-as-you-go models.