Bazel encourages you to list geographically diverse sources to download from for workspace setup. That said, you could run a local proxy with something like Squ

Bazel encourages you to list geographically diverse sources to download from for workspace setup. That said, you could run a local proxy with something like Squid or Varnish, turn on caching in a remote build server, or set up a mono-repo and never use npm (as Google does), each has advantages and tradeoffs... you could also archive and backup your Bazel folders to hermetically reproduce workspaces and builds if patching is necessary, though you’d have to also archive a copy of your host or build environment if you’re paranoid about host tools or configurations changing.