Calle launches BitNotes, a multi-mint Cashu wallet that prints ecash on paper

The free, open-source app for Android and macOS turns Bitcoin-backed ecash tokens into physical notes that can be checked offline Bitcoin has spent years trying to act like cash. A pseudonymous developer has now taken that idea literally. Calle, the developer behind the Cashu ecash protocol, announced BitNotes on October 22, 2026. It is a free, open-source, multi-mint Cashu wallet that lets users print ecash as physical paper notes. Those notes can be verified offline before anyone tries to redeem them. At its core, BitNotes is a wallet for Cashu, an ecash system built around Bitcoin.