Thanks, this was a good overview of some of the challenges involved with designing a capability language.

I think I need to read up more on how to deal with (avoiding) changes to your public APIs when doing dependency injection, because that seems like basically what you're doing in a capability-based module system. I feel like there has to be some way to make such a system more ergonomic and make the common case of e.g. "I just want to give this thing the ability to make any HTTP request" easy, while still allowing for flexibility if you want to lock that down more.

In Java DI you can add dependencies without changing your public API using field injection. But really there needs to be a language with integrated DI. A lot of the pain of using DI comes from the way it's been strapped on the side.