I'm a bit confused 😀 I read a bit about the Ark Protocol some time ago, and am looking forward to using it more! At 'Arkade.money', I expected to be able to pay with Lightning to top up my (Ark?) wallet. I assumed it would be able to pay the ASP (or something like boltz) to get a small Ark balance by paying a small Lightning invoice But arkade.money wanted me to send to an on-chain address. I thought that Ark could stay entirely off-chain until a user chooses to exit?

I haven’t tried it yet, but here is what I understood. Ark is a payment batching protocol on top of Bitcoin L1. When you want to embark an ark you send a UTXO (thus onchain payment) to ark provider that will give you in exchange some Virtual UTXOs (VTXOs). These VTXOs can be exchanged in the ark provider. The only involvement of lightning, afaik, is for moving VTXOs between different ASPs and between different layer. Does it make sense?

My assumption was that ASPs would have some (Ark) balance already prepared in advance, and that they could therefore send some of that - via a VTXO - to new users like me. And I assumed that - to pay the ASP for this service - I would just need to pay the ASP somehow (e.g. via Lightning) So basically, I thought I could pay the ASP via Lightning, in return for a VTXO. I think that _should_ be possible in Ark in theory, and I think that would be fantastic for onboarding new people

... although I guess there's nothing stopping other people (like you or I!) from implementating this on top of Arkade We could maintain a balance on Ark, and then sent that balance to noobs in return for a non-Ark payment (Lightning, Cashu, on-chain, ...)

A small update. They now do have an option to send via Lightning. It wasn't there last night, but now I can click 'Lightning invoice' and new QR code appears. But it doesn't really work yet. I tried to send 500 sats and the payment failed. One of my Lightning wallets told me that the receiver doesn't support the keysend feature Anyway, I'm happy that they are working on this, and I assume they'll get it working sooner or later! Who are Arkade? Are they open source and so on? I can't find that info on their wallet

Sorry for the late response! Yes, everything is open-source, here is the link:

GitHub

Arkade

Bitcoin is Programmable Money. Arkade has 10 repositories available. Follow their code on GitHub.

Thanks! I'm more inclined to be excited about this - and maybe contribute someday - if it's open source. I've been thinking for a while that cashu mints should also be ASPs (Ark Service Providers). This Arkade code, and the Cashu code, should be linked together so that people can just trivially deploy them as a combination and to allow easy swaps between Ark and Cashu And also, we should have wallets that combine all this: Cashu and Ark for new users and small balances, with support for on-chain and Lightning too. I accept that Lightning support would practically require something like the Phoenix model, as each phone can't be a fully Lightning node, but I like the idea of putting all the 'lightweight device, beginner friendly' options into one app with easy swaps between them

Yeah, this is the idea behind a graduated wallet, which accompanies a user in the different steps from full custodial to self-custody!

Btw, cashu is adding support for onchain mints if I’m not mistaken. Given the fact that Ark works with the same principle (VTXOs), it should be quite effortless to have a mint on Ark. What do you think?

Indeed. On-chain is, I think, being discussed here:

GitHub

onchain bitcoin payment method by gudnuf · Pull Request #283 · cashubtc/nuts

CDK onchain cdk#995 Nutshell cashu-ts implement onchain (NUT-26) cashu-ts#349 nutmix

I guess that the Cashu proposal assumes that the transaction will be signed and immediately broadcast for confirmation. But I suppose it's shouldn't be too hard to send the signed-but-not-broadcasted vTXO to the ASP instead. Although maybe it's more complex and might require the ASP's involvement (and signature) too

My desktop client (iris.to) thinks every instance of 'cashub' in a post is a cashu token 😀. They should look at the capitalization - i.e. cashuB (or cashuA for earlier versions of Cashu)

I don’t really know, unfortunately I’m not so knowledgeable. But I guess that the mint operator would have to be inside an Ark to receive VTXOs and then minting tokens.