See Advent of Code.
Located here, this script downloads all puzzle input and puts it in the input directory (mine is there in this repository). Time between downloads and which years to download can changed in the script. Puzzle input is user-specific, so a session id is needed. Get this from your browser while logged in.
Instructions (Firefox): On the Advent of Code website, open the inspector (F12), go to the Storage tab, in Cookies click https://adventofcode.com and look for the value of the session cookie (a 128 characters long hex string at the time of writing). Run the downloader script and paste this session id when it asks for it.