Developer Calle Releases BitNotes Ecash Wallet App
The new open-source tool enables users to print physical ecash notes and verify them offline.
Updated on Oct. 23, 2026 in Software
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Developer Calle has launched BitNotes, a free, open-source multi-mint Cashu wallet available for Android and macOS. The application allows users to convert Bitcoin into paper-based ecash notes that can be verified offline.
Why it matters
The tool is specifically designed to provide financial access in regions where banking infrastructure is limited or internet connectivity is unreliable. By enabling offline verification and physical notes, it seeks to bridge the gap between digital assets and local commerce.
BitNotes is built as a multi-mint Cashu wallet that leverages the Ark protocol to convert on-chain Bitcoin into tokens. The application also includes specialized integration for Rwandan Francs and supports both Android and macOS platforms.
The players
Calle
Calle is the software developer who created the BitNotes application and the underlying Cashu protocol.
The details
BitNotes facilitates transactions by routing them through independent mints and automating swaps, with users generating physical notes verified by mint public keys. The software is released under MIT and Apache licenses and integrates with Bitcoin Lightning for digital transfers.
Timeline
October 2022: Development of the Cashu protocol began.
October 22, 2026: Developer Calle officially released the BitNotes application.
The Tech Race
The introduction of BitNotes signals a major push to make the Cashu protocol a practical tool for daily financial transactions. It replaces traditional reliance on constant network connectivity by prioritizing offline verification and physical representation of digital assets.
Users in areas with unstable internet can now hold and verify ecash without needing constant cloud or server access. The app enables individuals to move between traditional currency bridges, such as the Rwandan Franc, and digital assets with greater ease.
The takeaway
BitNotes offers a novel approach to financial inclusion by allowing digital currency to be treated with the physical utility of cash. Users should exercise caution as the application has not yet undergone independent external security audits.
Further reading
Learn more about the latest innovations in digital tools within the Software section.
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