Ethereum Foundation launches zkAPI for private AI payments
The Ethereum Foundation has launched zkAPI, a system that allows users to pay for AI model access without revealing their identity. Users deposit USDC into an Ethereum vault and authorize spending with zero-knowledge proofs, ensuring the API provider cannot link requests to a payer.
Key takeaways
- Ethereum Foundation launched zkAPI on October 1, 2026 for private AI payments.
- Users deposit USDC into an Ethereum vault and authorize spending with zero-knowledge proofs.
- The API provider cannot link requests to a specific payer, enhancing user privacy.
- zkAPI separates payment and usage data so neither party sees both identity and query.
- The system uses USDC, a stablecoin pegged to the US dollar.
The Ethereum Foundation has introduced zkAPI, a system that lets users pay for AI model access without revealing their identity. Users deposit USDC into an Ethereum vault and authorize spending with zero-knowledge proofs, ensuring the API provider cannot link requests to a specific payer. The system separates payment and usage data so that neither the provider nor the payment layer sees both who the user is and what they asked.
How zkAPI works
Users prepay for AI services by depositing USDC into an Ethereum vault. When they want to query an AI model, they generate a zero-knowledge proof that authorizes a bounded amount of spending without revealing their identity. The API provider sees the requests, and the payment layer sees the spend, but neither can link the two. This design, detailed in the Ethereum Foundation's announcement, means no single party ever knows both who paid and what was asked.
Why privacy matters in AI payments
Privacy is a growing concern for AI services, particularly in sensitive fields like healthcare and finance. zkAPI addresses this by ensuring users can access AI models without compromising their identity. As Decrypt noted, the system lets users query AI models through cryptographic proofs so that no single party sees both who they are and what they ask.
What this means for you
For users, zkAPI offers a way to interact with AI services without linking their identity to their queries. For developers, it provides a privacy-preserving payment tool that can be integrated into applications. This could encourage broader adoption of AI services by users who are wary of sharing personal data.
The broader context
zkAPI arrives as zero-knowledge technology gains traction across the crypto space. The Ethereum Foundation previously launched better.codes, an open research challenge to improve hash-based SNARK security. Separately, World open-sourced ProveKit, its zero-knowledge identity toolkit, in September 2026.
Frequently asked questions
What is zkAPI?
zkAPI is a system developed by the Ethereum Foundation that allows users to pay for AI model access without revealing their identity. It uses zero-knowledge proofs to authorize spending.
How does zkAPI ensure privacy?
zkAPI ensures privacy by separating payment and usage data. The API provider sees the requests, and the payment layer sees the spend, but neither can link the two.
What cryptocurrency is used with zkAPI?
Users deposit USDC, a stablecoin pegged to the US dollar, into an Ethereum vault to use zkAPI.
Who benefits from zkAPI?
zkAPI benefits users who value privacy and want to keep their AI usage separate from their personal data. It also provides developers with a new tool to integrate privacy-preserving payment systems into their applications.
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