Did you check the specs already? Is that somewhat compatible with L402? https://www.l402.org/
Coinbase jumped on the 402 bandwagon... yay!
When I talk to people about Cashu they usually ask me: "Why do we need Cashu? We got Bitcoin and Lightning". I used to tell them that Cashu offers a great alternative to custodial Lightning, but with better privacy. While this remains true, my answer today is that Cashu enables new use cases (or simplifies them drastically) where Lightning and Bitcoin struggle.
One example are Zaps. NIP-61 Zaps offer a very similar experience and value proposition as NIP-57 Zaps do, but require only a fraction of the implementation overhead.
The second example (and inspiration for this post) is HTTP 402. With Cashu, we can streamline payments for requested ressources into a single request. Because Cashu is a bearer asset the whole flow is pretty stateless. It is stupid simple to implement this. While it is definitely possible to make 402 work with other "assets", using Bitcoin / Cashu makes it a breez.
This is my favourite thing about Cashu.
https://blossom.primal.net/b0798bba893532f8eea97928c329a7a78a94f866dd3b71949f32a805198d1752.mov
Discussion
x402 is very verbose because it's goal is to make 402 work with many different blockchains. It also outsources a lot of work from the resource server to other entities (which makes sense when working with blockchains, especially multiple ones).
l402 on the other hand is similar to Cashu 402, but iirc is quite stateful, as it substitutes Lightnings non-bearer-asset nature by using macaroons.