apt-cache

Setup on Debian with apt-cacher-ng

https://wiki.debian.org/AptCacherNg

apt install apt-cacher-ng
apt install avahi-daemon

Client

echo 'Acquire::http { Proxy "http://proxy:3142"; }' | sudo tee -a /etc/apt/apt.conf.d/proxy

should also work automatically with

apt install auto-apt-proxy