Observed arrival · 2026-10-24
Cashu Card puts ecash on an NFC smart card
An NFC smart-card implementation of Cashu ecash, with a draft protocol, code, installation instructions, and a phone-based tap flow.
○Open
⊠Login
$Paid
†Ads
✦Pretty
●Pro
◎Niche
◉Human
⚑Risk
ƒJS
- For
- Cashu developers and merchants testing offline ecash
- Worth noticing
- A 21-sat example names 1-, 4-, and 16-sat pieces; the merchant bears double-spend risk until mint settlement.
Field notes
The card’s key is generated on the chip and stays there; a wallet loads ecash into 128 slots, with eight unspent pieces shown in the example. At checkout, the merchant phone chooses denominations, receives a one-time signature, and checks mint signatures offline. That acceptance is provisional: the page says the merchant carries double-spend risk until the phone later reconnects and swaps the pieces with the mint. The protocol is explicitly marked as a draft.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
○OpenPublic substance visible
⊠LoginAccess appeared gated
$PaidCommerce or pricing visible
✦PrettyNotable craft visible
●ProPolished or operationally mature
◎NicheUnusually specific use
One card from the complete issue