I’m referring to projects like redlib or invidious.
I was thinking about doing something similar for a local second-hand marketplace and got curious. Redlib seems to use token spoofing to get past rate limits and Invidious doesn’t even use the official YouTube API.
The only way I thought of, which would be slow, is to scrape the site (like you would with Beautiful Soup).
RedLib and Invidious hoster here;
I can confirm they do not use any backend API, however this means eventually they (YouTube and Reddit) kick on automatic rate limiting after a while and I have to switch up my vpn connection on my server. it’s annoying, but it works if you know a thing or two about proxies and web scraping (the knowledge from scraping can be cross applied to implementing a suitable proxy config)
that said, RedLib’s backend token spoofing works a lot better than the Invidious method (Invidious emulates web traffic via Android mobile devices and gets the videos from Google Videos directly, bypassing YouTube for the heavy lifting).