I just came across ICPay, which seems to already support x402 Ethereum payments on ICP.
@icpay I can’t find much in the docs about how ICPay works under the hood and code seems to be closed source? Are you using threshold signing to submit transactions or how does it work? I guess ICPay has custody of user funds?
Hey! Very happy you found icpay, we support payments in ICP, ckBTC, ckETH, ckUSDC, ckUSDT on ICP. We also support x402 and Base payments.
It is not a fully open-source project, but integration with icpay is free, icpay-sdk and icpay-widget are public. Interestingly, we do not custody user funds they are all held in smart contracts accessible only to the parent wallet.
As for how we are dealing with x402, it follows Coinbase’s guidelines and standards - using EIP3009 and signed payload header as per specifications and ed25519 signature.
There is some more info on docs.icpay.org but feel free to reach out to me hello@icpay.org or @tatruso on Telegram and we can discuss further.