This is a problem space our company (coil.com) is actively working on. Part of our approach is proposing an open standard https://webmonetization.org/ and are actively working with browser vendors and W3C.

It is a chicken and egg problem though as browsers won’t implement anything without scale and it’s difficult to get scale without lots of users. We polyfill it with a browser extension. It’s not a great solution though.

We always looking for feedback and users :)

I hadn't heard of this before. It would be nice if it works. Do you think that implementers could do so cost-effectively? (That is, not have to charge $1 to send $.01?)

Gotta say, this code sample on Interledger kinda threw me:

  fetch('http://localhost:8080/', {
    method: 'GET',
    maxPrice: 5000,
    plugin
   })
Seems like this kinda thing that would mandate https.

Would you expect https to be required on localhost? You gain very little (or nothing?) by doing it, but you do lose by adding complexity. Especially since you can't get let's encrypt to automatically issue a widely trusted certificate for localhost.

You don't need let's encrypt for a dev environment, you can use something like https://github.com/FiloSottile/mkcert and run Caddy locally to reverse proxy to whatever you need for development.