@ Dikaios1517
2025-05-13 16:38:17
Dang, there’s a lot to chew on there!
I think you are probably correct that Cashu is the future for zaps. However, there are a few things that have me hesitant about it.
First, Cashu is by its very nature custodial only, unless you are running your own mint, and there are far less folks running their own mint than there are running their own lightning node. If Nostr goes the direction of eCash exclusively for zaps, it will mean that almost all users have to trust a custodian. Yes, the vast majority already are doing so, but there are still plenty of us out there who zap from our own nodes, and unless we also want to learn how to run our own mint, we’re going to have a meaningful percentage of move over to using custodians instead.
Next, I am not a fan of the idea that someone can receive funds without any intentional setup of a wallet to receive them to, particularly at a time when not all Nostr clients have Nostr wallets built into them so that the user sees within the app’s UI where they can go to retrieve those funds. The user should always be in control of how they receive funds. We probably need something like a “Preferred Payment Method” note kind that flags whether or not the user wants to accept Cashu or Lightning, and if the note can’t be found, clients should default to Lightning if they have a Lightning address in their kind 0, or treat them as unzappable if they have neither.
It’s funny that you mentioned you have found NWC to be unreliable. I have actually found NIP-60 wallets, such as Nutsack, Honeypot, and the one built into Olas to be unreliable. I have yet to have a NIP-60 wallet that is built into a client work, so I have never had the pleasure of trying out zapping with it. Now, that could entirely be due to the fact that it was Olas, a Pablo app, that I was trying it out with, and Olas is just broken… I would definitely be willing to check out other clients that have NIP-60 wallets if you have suggestions.
Also, there is nothing intrinsically tying eCash to Bitcoin’s fixed supply. Now, you can say this is an issue for custodial Lightning as well, but there is an important difference, especially in the context of zaps. Whenever a zap happens on Lightning, the custodian has to prove they actually have the sats, because they will be routed to the receiving wallet via payment channels, unless the receiver happens to be using the same custodian. With Cashu, as I understand it, the receiver just gets tokens from the sender’s mint, regardless of whether they have a trust relationship with that mint or not, and if they want to redeem them over to a different mint, that is a separate transaction, even if it is done automatically. So they could end up receiving eCash as a zap, and when they go to redeem it, they can’t, because the sender’s mint was malicious and had no underlying sats. Unless there is a way to block receipt of eCash from mints you don’t trust that I am unaware of?
Outside of that, I LOVE the idea of Nostr wallets built on Cashu protocol, where the tokens are stored on your relays and you can just redeem them out to your Lightning wallet once you start building up a balance. Multi-mint payments are exciting. Web-of-trust based mint recommendations is exciting. I am generally bullish about Cashu, with the exception of my above reservations.
Now to work through what you wrote…
“The problem with NWC is that it’s quite unreliable in my experience and sluggish.”
Ironically, the only NWC connection that is currently unreliable and sluggish for me is when using Minibits with NWC. Outside of that, it works as quickly as any other Lightning transaction, and my only downtime has been when either my own node or the relay for passing NWC messages back and forth is down. Now, this could definitely be something Cashu tokens saved to multiple relays can address, since one relay being down wouldn’t affect my ability to zap or receive zaps.
“...the UX of copy pasting random strings all over the place is also a hurdle.”
I agree. I don’t think it’s as much of a hurdle as it’s made out to be, given that copy/pasting isn’t exactly hard to do, but the UX could definitely be improved. Alby Hub’s scanning of a QR code to establish the connection is really nice, and more NWC enabled apps need to support that option.
“...payments are much faster and more reliable, alas the balance could be unreliable…”
Tradeoffs, right? I absolutely see why Cashu payments would be faster. No need to calculate routing paths and such. Just find out the receiver’s inbox relays and save the token there, encrypted to their npub. But balance information is going to be an interesting one to try and solve for, with a single user likely having received tokens from several different mints, and they may or may not all be saved to the same relays… Users will also need to be careful about changing relays, since they will need to make sure they migrate their tokens to the new relay they want to use first. Hopefully that will be made clear in a Nostr client’s UI, along with some built-in tools for doing so.
“...you don’t need to pray to a node to publish a zap receipt…”
YES! Absolutely this is an improvement on the current way things are done with Lightning receipts! Since the transaction is happening ON the relays, Nostr clients can see that the payment has taken place, whereas with Lightning, the transaction itself is happening outside of the Nostr ecosystem, and therefore it relies on the node to confirm the payment was received.
“When you as an outside observer want to calculate reputation of a pubkey and pull in zaps…”
You might need to break this down further for me. Are you talking about using zaps as a method for calculating the reputation of a particular Nostr user, based on the reputability of the Cashu mints they are using?
“The way I see rn is that NWC has been a good interim solution but there is more potential in Cashu…”
This is probably true. And yes, the reason I am so excited about NWC is probably because I run a node, and it so easily resolved my remote connection issues. Couldn’t stand using Tor and having to wait and hope that Zeus would be able to connect so I could see my balance and make a transaction…
Cashu absolutely does have a lot of potential, and I love to see the new developments and improvements coming along. I don’t think we’re ready for it to take over fully, even on Nostr, but it’s getting there.
I see NWC as an interesting option for setting up recurring payments, with a budget, too. For instance, if you have a service provider that you want to be able to pull a payment every month, you can give them a NWC connection that you maintain the ability to revoke at any time, and with a budget of exactly the monthly payment, so they can’t increase the price on you without your permission. So, NWC could still be useful outside of a Nostr context, and even paired with a Cashu wallet, such as Minibits.
Imagine a NIP-60 Cashu wallet app that had NWC for interacting with the broader Lightning ecosystem as well. In fact, I don’t see why NWC couldn’t be modified for reoccurring payments with eCash, too, so the wallet would send via Lightning if the receiver prefers, or send eCash instead if the receiver doesn’t mind having tokens from the sender’s mint(s). NWC is really just a means for messages to be passed between two apps, with the one who created the connection dictating the terms of what sorts of messages are permitted and what information they can or must contain. Heck, a user could have a NIP-60 wallet that supports creation of NWC connections that they use to connect it to an Alby account so they also receive Lightning payments to the same wallet, and they can use the Alby extension to make payments from their NIP-60 wallet to an online retailer that accepts Lightning, but not eCash.
So, I think NWC and NIP-60 wallets can absolutely coexist and complement one another.