The feature lets phones exchange Bitcoin-backed ecash tokens without internet access, extending Cashu’s push into contactless payments as wallets and merchant apps build around the protocol.
Cashu creator Calle demonstrated an NFC (near-field communication) tap-to-pay feature on July 7 that lets two phones transfer Bitcoin-backed ecash tokens without an internet connection, with the sender side requiring no connectivity. The open-source protocol uses bearer-style ecash tokens backed by Bitcoin or Lightning Network deposits held by third-party mints, allowing value to move directly between devices without blockchain confirmation delays at the moment of payment. The design separates token issuance from spending, so users can hand over tokens with a tap in a way that resembles physical cash while avoiding an on-chain transaction for each transfer. The demonstration adds to a growing ecosystem around Cashu, with Minibits supporting token transfers, Numo building point-of-sale functionality for merchants, and earlier 2025 work including NFChat for NFC wallet transfers and improved offline receiving in Nutstash. Cashu’s architecture traces back to David Chaum’s eCash ideas from the 1980s and continues to receive support from OpenSats. The model could expand Bitcoin payments in places with poor connectivity, though it also raises trust and regulatory questions because users must rely on mints to hold backing funds and honor redemptions while transactions leave no on-chain trace.