OpenCash

The OpenCash Association is a Swiss nonprofit that funds and coordinates open-source work on Chaumian ecash systems built on Bitcoin. Its focus is the Cashu protocol, which lets users hold and transfer sats-backed ecash tokens with strong privacy guarantees. Mints issue tokens and handle Lightning settlement; users transact without revealing their identity, balance, or counterparty to the mint.

OpenCash operates through grants, bounties, and community coordination rather than shipping a single product. One bounty funded a BTCPay Server plugin that lets merchants accept Cashu payments or swap tokens automatically to Lightning. A Cashu track at the 2025 Bitcoin Designathon produced wallet UX patterns for setup, backup, multi-mint management, and NFC payments. Recurring public developer calls keep implementations aligned on standards like WebSocket subscriptions (NUT-17) and payment requests (NUT-18).

Why fund it?

Nobody owns Cashu. Wallets, mints, and libraries all implement it independently, but protocol coordination, bounties, design resources, and documentation still need funding. That's what OpenCash does.

OpenSats announced its support for OpenCash in Let a Thousand Flowers Bloom.

What's next?

OpenCash maintains opencash.dev as the central hub for grants and bounties, and contributes to cashu.space and docs.cashu.space as entry points for developers and users. For a detailed look at recent progress, see the Advancements in Ecash impact report.