You should maybe watch this video of David Marcus paying for coffee on a Square terminal using a stablecoin called USDB on bitcoin.
Well, this is an interesting thing: David Marcus from Lightspark paid a dollar invoice on a Square terminal using a stablecoin called USDB in a Spark wallet...and the whole payment took place on Bitcoin rails.
What the hell does that even mean?
I do not understand how all these things work together or even why they are necessary, so I did a little poking into each piece to see if I could understand what is going on:
First off, Lightspark is the parent company of Spark. Fairly easy to understand.
Spark is kinda like a statechain (#969221) and they claim you have unilateral exit back to bitcoin, which you might have if you have a large enough vUTXO, but when it comes to lightning directly from Spark, it seems more less like custodial lightning.
Second, Square terminals started allowing merchants to accept bitcoin payments via lightning (#1279069). This is custodial: the merchant doesn't actually have a node or any channels, but Square does.
Third, in June of this year, a company called Flashnet introduction posted this announcement:
Today, we’re introducing USDB, the first regulated, USD-backed stablecoin built directly for native Bitcoin. Issued by Brale, a U.S.-licensed entity, and distributed in partnership with Magic Eden, USDB puts a stable unit of account natively where it belongs: on Bitcoin.
Flashnet has this diagram to show what they are:
It's not exactly a full explanation, but it looks like Flashnet stuff happens in Spark and probably involves a vUTXO and they are saying it's "on bitcoin" because Spark has rough, kinda unilateral exit.
Then we've got this company called Brale. On their website, Brale says this about themselves:
Brale makes it easy to issue, move, and manage stablecoins. Using our services you can create your own stablecoin and leverage our APIs to power on/off ramps, automate payouts, or move stablecoins across ecosystems. Brale's APIs support Brale, Paxos, and Circle-issued stablecoins. Stablecoins created with Brale are usable for various use cases and can be swapped at any time with other popular stablecoins.
As the Flashnet announcement points out, Brale is a U.S. licensed entity, so that seems to be an important part of all this. On Brale's website, here's what they have to say about USDB:
USDB is the first regulated, USD-backed stablecoin issued natively on Bitcoin. Issued by Brale in partnership with Flashnet and Magic Eden, USDB enables builders, traders, and institutions to quote, settle, and hedge entirely on the world's most secure ledger for the first time.
So that brings us to a new thing: Magic Eden, which is pretty much an NFT marketplace. Their website hurt my computer and made it want to cry. On their website they claim:
We’ve built the largest cross-chain NFT marketplace and the #1 Bitcoin app, and with our acquisition of Slingshot, users can trade over 5 million tokens across all major chains. Our growing product suite includes a cross-chain wallet, mobile, advanced trading tools and the ability to mint, collect and trade, well, anything.
And finally, there's also this thing called Bridge, which had this to say about USDB in its announcement:
USDB is an infrastructure stablecoin issued by Bridge that's always backed 1:1 by the equivalent value of US dollars held in cash and short-duration money market funds at BlackRock. Unlike traditional stablecoins where issuers retain the economic benefits from the underlying reserves, USDB introduces a more equitable model where these benefits can be shared between the issuer, developers, and end users.
So what the hell is going on?
I don't really know why all these different things are necessary to make a payment at a coffee shop, but I'm going to take a shot at explaining it:
So, David Marcus had a wallet on his phone. That wallet interacted with Spark kinda like a Liquid wallet interacts with Liquid. Because it was interacting with Spark, David was able to have a bitcoin balance (held in vUTXOs) and a stablecoin balance, held as USDB in some kind of contract in a Spark vUTXO.
The USDB was issued by a company called Brale, which maybe uses Bridge to interact withe the USD tradfi system.
When David paid for his coffee, the wallet traded his USDB for bitcoin on Magic Eden. The bitcoin was then given to whoever runs Spark's lightning node and then it was routed over normal lightning channels until it got to Square's lightning node. Square then credited the merchant terminal for the payment.