Buterin uses Kohaku-CLI for private Ethereum payments

Ethereum co-founder Vitalik Buterin revealed in an October 31 essay that he employs the kohaku-cli command-line tool for private payments and a separate AI-written tool for ENS IPFS content-hash updates. Buterin distinguishes the two: the payment wallet manages privacy protocol transactions, while the ENS updater handles naming system records.

Local Control Over Web Interfaces

Buterin shifted away from web interfaces to retain control over the software executing his transactions. He noted that websites deliver application code from servers, making users dependent on the specific revision provided at access. Local applications allow users to choose, retain, and replace software revisions, reducing exposure to repeated code delivery.

The kohaku-cli documentation warns that the tool is unaudited, under active development, and AI-assisted. It advises against mainnet operations unless users fully grasp the potential for catastrophic fund loss. This warning applies to the wallet application specifically, not the broader Kohaku toolkit of protocol libraries and infrastructure.

Technical Architecture and Signing Risks

Kohaku-cli manages public Ethereum accounts and private balances via Tornado Cash, Railgun, and Privacy Pools V1. Installation requires Node.js 22 or later, using npm install and npm run build. At commit 0ef5c44, the manifest lists version 0.1.0 and pins dependencies including viem, Kohaku packages, and a Git dependency for kohaku-artifacts.

The tool’s architecture processes transactions in distinct stages. Public transfers use a dry run before broadcasting, requiring a private key to build a local wallet client. Conversely, private operations like Railgun unshielding can output a signed UserOperation even if broadcasting is withheld. Consequently, withholding submission does not always mean withholding a signature; compatible tools can later submit the signed operation via a Pimlico bundler.

The CLI includes --non-interactive and --broadcast flags for submission without confirmation prompts. While simulation and parameter checks remain, this feature suits scripts and agents. The README details encrypted disk seeds and owner-restricted password files for POSIX automation to govern secret access.

Provenance and Network Privacy

SLSA software provenance standards allow users to verify artifact origins by checking signatures and matching digests. These checks rely on the verifier’s trusted builders and source expectations. Because recursive verification of resolved dependencies is optional, authenticating a top-level artifact does not automatically authenticate every input.

Network privacy is distinct from application delivery. Kohaku-cli documentation notes that Tor is the default for certain non-RPC traffic, though Ethereum RPC traffic uses ordinary network connections. Running the interface locally does not ensure every external interaction is private.