For the MetaMask plugin system we want to allow scripts to request permission to use web APIs (like fetch, or websockets), but ideally confined in a variety of ways, for example what domains those APIs would be allowed to access.
It occurred to me that there is probably a shared ecosystem need for a collection of Proxy wrappers for web APIs to confine them in common ways, and I mostly expect this doesn’t exist yet, but I figured I’d open this thread to both ask if anyone has written proxies for confining common web APIs, and as a place to post them as they are written, as I see a few of them in my near future.