I was thinking a simple way to do it might be to also store the cookie info in a DB online. When the user visits from the cookied machine, allow them to create a "one time use" URL with a GUID which dies say 2,7,30 or whatever, days later. The URL can be shared by the user to whoever they ...

I signed up to say, I went looking for a service exactly like yours. A friend was starting to play factorio and we tried to play together. Self-hosted wouldnt work but we found your service and (very skeptically) I ran a server and 5 hours of laughing and fun later we signed off (and have played sev...