Bounty Context
I got a question from a dev in another ecosystem about extending lightning and I've written my best effort at addressing it, but I'm a bit lost. The bounty goes to the best answer to extend, elaborate, or refutes my provisional answer to provide a better one. Assume the audience is a dev from another blockchain ecosystem just getting familiar with Lightning. Zaps go to anyone providing a solid as well.
Question from Dev
What im looking to do is "a decentralized lightning node client that extends the network". Like many nodes working together to be one node on lightning network or maybe many instances of that.
Provisional Answer
The best short answer is Cashu coming from Peter Todd's review article [1]:
...This is also why so many future L2 systems are expecting to also participate in the Lightning network. We also see this in how existing not-quite-L2 systems like Cashu rely heavily on the Lightning network to actually be useful: the primary usage of Cashu is probably to send and receive Lightning payments...
I don't know much about Cashu though so I'll lay some extra information...
It's not a new idea that lightning would be the "common language" of other Layer2's as Roy Sheinfeld layed out in his blog last month [2], [3].
One way to get a more concrete / code-oriented view of that is to check out this presentation from TABconf this week [4], [5]. (I think recordings should be available soon for this.)
If you want something very simple to prototype with, I'd recommend LNBits plugins on LND running on Voltage for a custodial lightning prototype app [6], [7].This won't "extend" LN on new nodes but simply give each user a separate wallet.
References
[1] https://petertodd.org/2024/covenant-dependent-layer-2-review
[2] https://medium.com/breez-technology/lightning-is-the-common-language-of-the-bitcoin-economy-eb8515341c11
[3] https://www.youtube.com/watch?v=sgaTlU2pEPs&t=1138s
[4] https://github.com/supertestnet/l2_generator
[5] https://github.com/TABConf/6.tabconf.com/issues/35
[6] https://github.com/lnbits/lnbits
[7] https://www.voltage.cloud/
5,000 sats bounty