The current WebExtensions JavaScript API is very weak. Many useful functional ideas cannot be realized.
For example, if I want to implement a clipboard management extension that statistically intercepts junk clipboard content, I need the hook clipboard API, but the current API simply cannot achieve such functionality.
There are still many things like this.
Yeah, you’re right the current WebExtensions API is quite limited in a lot of areas.
Clipboard access is a good example. Because of security restrictions, extensions don’t get low-level hooks, so things like real-time clipboard filtering or interception aren’t really possible in a clean or reliable way.
Most of these limitations are intentional for privacy/security reasons, but they do make it harder to build advanced utility tools like the one you described. In many cases, developers have to rely on workarounds or reduced functionality instead of full control.