[immibis]

We need a browser or extension that does this stuff automatically in the browser, so it looks like a normal browser request.

By "this stuff" I mean BreezeWiki, Invidious, Nitter, whatever that one for Reddit was called.

[pfg_]

Can't work for twitter because they block logged out requests (unless you're logged in)

[Dracophoenix]

There's already an extension called LibRedirect that can do this.

[noirscape]

Fully in the browser is unfortunately impossible/unworkable due to CORS (basically the same technique that prevents someone from easily faking a bank login page to leak your details/allowing for XSS attacks prevents you from doing this locally).

We're essentially reliant on these serverside solutions to proxy requests because that's the easiest way to do cross-origin requests without making whatever browser deity you annoyed that morning suddenly angry at you. (Extensions can mark domains to be allowed to run on, but this is restricted by the manifest, allowing for really easy whack-a-mole by server authors, not to mention the fact that each update would need signing from Mozilla/Google.)

Irritatingly, the same mechanism that's used to stop fraudulent sites can also be used as an easy deterrent against deshittification interfaces.

[immibis]

Of course it's possible. CORS is a way for a browser to sandbox one site from another. When you are the browser, or an extension, you don't sandbox yourself from doing things you want to do.