Ethereum Foundation puts private API payments on mainnet
Ethereum Foundation and Open Anonymity put zkAPI on mainnet Oct. 1, separating AI API payments from identity while leaving prompts and IP addresses visible.
The Blockheight Editors··2 min read
The Ethereum Foundation and Open Anonymity Project launched zkAPI on Ethereum mainnet on Oct. 1, letting users pay for metered AI services without linking their payment identity to their requests, according to the Foundation’s announcement. The system uses zero-knowledge proofs to separate payment from API use.
Users deposit ETH, USDC or other supported funds into an Ethereum vault, then prove they have an unspent balance when requesting service. The Foundation says the Open Anonymity Project built the system with its dAI team; the GitHub repository describes the protocol as experimental.
How does zkAPI separate payment from an AI request?
A client on the user’s device sends a payment proof to a zkAPI server, which issues a short-lived API key with a spending cap. The user’s prompts then go directly to the AI provider in this mode, while the server handles authorization and later settles the bill using a signed usage receipt, the Foundation says.
One authorization can cover a session rather than requiring a proof for every model call. The key reserves a capped amount, and the server deducts the actual metered usage when the key expires. The Foundation says users can close their balance and withdraw remaining funds onchain.
What information can the provider still see?
The design hides the link between a user’s deposit and API requests; it does not hide the prompt or the user’s network address. The Foundation says providers can see request content and metadata such as an IP address, and may connect sessions through repeated personal details or writing style. The payment server does not receive prompt content in the runtime-key mode.
Unchained reported that Open Anonymity also offers zkAPI as a payment option in its OA Chat app. The Foundation says the local client supports standard OpenAI and Ollama APIs.
What happens after the mainnet launch?
zkAPI is live on mainnet, but the Foundation’s announcement does not identify other AI providers that have integrated it or say when wider adoption may follow. The project remains experimental, and users’ prompts and network metadata remain visible to providers.
Source material
- Foundation’s announcement — blog.ethereum.org