Container & Extension Proxy

Container & Extension Proxy is a fork of the original "Container proxy" extension by Aleksey Bekh-Ivanov (original code: https://github.com/bekh6ex/firefox-container-proxy — original listing: https://addons.mozilla.org/firefox/addon/container-proxy/). All credit for the original extension goes to its author. This fork does not claim any originality or priority — it simply adds one feature on top of the existing extension.

Like the original, it lets you assign a proxy (SOCKS4, SOCKS5, HTTP or HTTPS) to each Firefox container, so that traffic in a given container goes through the proxy you choose.

What this fork adds: the ability to route another browser extension's own traffic through one of your already-configured proxies. Some extensions — SponsorBlock, for example — send their network requests from their own background context, which is not tied to any container. With container-only routing, that traffic went out directly and bypassed the proxy. A new "Extensions" settings page lets you map such an extension to a proxy, so its traffic follows the proxy as well.

Why a separate listing: the original project has had no activity for about five years, so the change was not submitted upstream. Published under the same BSD 2-Clause license as the original.