Calle I want to learn more about using ecash offline. Can you point me in the right direction to some resources?
Tap-to-pay with CashuBTC ecash — for bitcoin.
Fiat credit cards nailed the UX: fast, offline, works anywhere.
I always wanted that for Bitcoin.
Now it’s open-source. Private. Instant. Beep, done.
In the video: two Cashu wallets for bitcoin.
Left: nostr:npub1kvaln6tm0re4d99q9e4ma788wpvnw0jzkz595cljtfgwhldd75xsj9tkzv (PoS)
Right: cashu.me (payer)
Ecash is sent directly via NFC — no internet, no delay. Beep, boop.
Ecash is a bearer token — the money lives on your device, not on a server. That’s why it pairs so well with NFC. Pick an amount, tap to send. No talking to servers. No syncing. Just push it over. The payment is pretty much instant. A PoS can accept ecash from any mint and receive payments via Lightning.
Still early days, but we’re experimenting. Card-to-phone works, but phone-to-phone? That’s the real killer use case.
Apple famously locks down the iPhone’s NFC chip — good monopolist.
F*k that. I found a workaround.
As long as one phone (ideally the PoS) is Android, you can send data both ways between iPhone and Android.
(You don’t really own your iPhone.)
Peace!
Discussion
Some slides on that topic. I am releasing offline tokens feature to nutstash.app this weekend! I plan on writing a short blog about it. Stay tuned!
If we can use p2pk locks with ecash when both sender and receiver are offline... that would be ground breaking!
So I am very eager to know more. Currently I can't do it on chasu.me, but I assume there's a technical limitation that I don't fully understand yet. So want to understand more.