Geralt_of_Rivia: According to my experience you only get stuck in ReCraptcha hell if you either log in often within a short time or after several failed login attempts. And once your IP is flagged you will have to train the AI for the next 1-2 days if you want to log in before you get out again.
Through normal use you should never get recaptcha unless your memory is so bad that you screw your login up often or you share your IP with many other people (e.g. the IP of a VPN exit point). So logging in is actually as simple as a GET to retrieve a CSRF token followed by a POST with your email, password and the token.
I'd love to believe so, but certainly wasn't my experience in the past. Before making gogcli, I tried gogrepo and I got stuck into login hell. Never managed to actually try out the tool successfully because of the recaptcha.
In the end, what worked for me (and is gogcli's way to this day) is grabbing the bloody cookie from my browser session and sticking it in a file for the client to use although what sude describes seem somewhat simpler than that from a end user standpoint (I might actually try it out when I have more time), but it is still kind of hammy and not great for a user experience.
The only way to really make it really nice from a user standpoint and always working as Timamat16 mentions here is to use a browser engine (I might tryout a Tauri wrapper at some point now that I know Rust), so yeah, I think gog could make integrating authentication in third parties a lot better.
Anyways, I will not debate it to death in this thread, but that is my opinion, as far as authentication is concerned. Overall though, we are in agreement that the gog api could be greatly steamlined to allow third party clients to give a better user experience while backing up their collection (and also hammer gog's services less heavily while doing so).