[roasbeef]

Hi y'all, roasbeef here, the co-creator of the LSAT protocol!

Was really thrilled to see this link organically get so far up on HN. Since we initially released the linked website and corresponding blog post [1] a year ago, we've continued to develop Aperture [2], a pure-Go reverse proxy that natively speaks the LSAT protocol. We use Aperture in front of all our Lightning/Bitcoin related services, with the LSAT credential itself serving as richly featured API tokens.

We have a lot of cool stuff planned to bridge the gap here between the server-side/protocol and the web itself, in the form of a new "Lightning Browser Kernel" that'll abstract away a lot of the underlying flow, to make logging in or beginning to stream payments for a computational API as easy as clicking a button. Excited to be able to share more in this direction towards the end of the year.

On the web application side, since then developers like Buck have also started to release wrappers around _existing_ web application frameworks to allow developers to add Lightning-based monetization/metering/authentication directly into their web apps [3]. If you want to see the web app wrapper live, then check out this LSAT playground that lets you interactively produce/verify/satisfy an LSAT right from your browser [4].

Happy to field any questions related to LSAT our our vision of the Lightning Native web!

[1]: https://lightning.engineering/posts/2020-03-30-lsat/

[2]: https://github.com/lightninglabs/aperture

[3]: https://github.com/tierion/now-boltwall

[4]: https://lsat-playground.bucko.vercel.app/

[thinkmassive]

Awesome to see you drop in here! Great summary and related links.

For anyone interested in the Lightning Network in general, I'll mention one more great resource:

Builder's Guide to the LND Galaxy https://docs.lightning.engineering/

[Rafeeki9]

From the blog post link [1]: "This is rather powerful as it enables a strong decoupling of authentication and payment logic from application logic."

So an application could leverage the LSAT protocol for both auth and payments instead of Oauth and Apple Pay?

[roasbeef]

Exactly! Within the protocol, an atomic exchange happens where the user satisfies a payment over Lightning, and they receive the second half to "complete" their authentication token.

If this token is say 10 sats, then maybe it's just basic spam prevention for you to make an account on some online form. If it's say 100k sats, then maybe the LSAT itself also functions as a sort of licensing key or guards a download of some other artifact/file.

From the PoV of the application logic, all this happens "before" the main request even reaches the handler. If you're familiar with Python, it's as if you had a decorator on a handler that handled the auth+payment and only passed on valid requests once everything has been satisfied. Going even further, applications can start to utilize the power of macaroons to create LSATs that: expire after 24 hrs, or allow you to take your credential and make it read-only to give to your friend.

[jlrubin]

I've heard around the net that bitcoin can't really scale in terms of raw # of users -- even with LN, it's pretty capped (same number of users, but more txps).

If I want to build a web-scale startup how could I rely on something like LSATs to accomodate hockey stick growth?

[roasbeef]

I wouldn't necessarily agree that Bitcoin can't scale the number of raw users with something like LN. In fact, LN allows Bitcoin to reach a _wider array_ of users that may be priced out of doing routine transactions on the base chain. Excited to continue to see how the situation in El Salvador develops, as we now have our patient zero in the form of an entire country!

It is the case however that either scaling ceiling or costs prevent everyone from possibly _creating_ a root UTXO eventually. In this direction I'm excited about concepts like multi-party channels that allow users to conjointly share a UTXO and perform off-chain transactions using it. Another very powerful upgrade on the horizon for Bitcoin are the various flavors of covenants like BIP-119, that'll allow us to do things like open 100k Lightning channels in a single on chain transaction, in an irrevocable manner.

LSATs are interesting for start ups, as they allow for a lot of new experimentation w.r.t business models and pricing. Most say SaaS start ups typically allow for a free trial, then force users directly onto a subscription payment. Combined with the open nature of Bitcoin (anyone around the world can use it), LSATs and LN allows developers and entrepreneurs to potentially capture some of the user base that drops off after the free trial by advertising an in-between tier: stream the payment as you go.

Services like bitclouds.sh capture this spirit, as you just need to top off your account (zero log in, zero sign up, just sats) and you gain access to a VPS you can access. Sure you don't want to do anything very sensitivity in a instance like this, but it's perfect for running CI tests, building containers, etc.

The natural progression of LSAT powered bitclouds.sh-like services is a sort of programmatically driven distributed Function-as-a-Service network, wherein agents of the network are able to programmatically gain access to various computational resource or services all without being locked into any particular platform or having to be worried that a data leak will expose all their private information. So stuff like robots renting VPS space (payments streamed by the minute over LN) to be able to transcode some captured video to submit to a mechanical turk-like job listing.

[1]: https://www.bitclouds.sh/

[2]: https://github.com/bitcoin/bips/blob/master/bip-0119.mediawi...

[buck-o]

One nice thing about lsats is that you can have access to some network-based endpoint gated by payments but that authorization kind of carries its state around with it (to an extent). So you can do micro-payments as opposed to... nano-payments where one small payment can be re-used to access gated content and the lsat itself can be shared, delegated, even potentially sold and re-sold. On its own this probably doesn't take care of the number of users that can onboard onto lightning (I heard on the net that something like the Check template verify opcode, OP_CTV, can help even more on that end), but it does expand the scale of what could be done with a single channel which itself expands on what can be done with a single UTXO.