So lets say my site is Examplesite.tld A user logins and i set this infomation. Then they go to Examplesite63.tld which is different company and different server. The script on there site gets that and other data then other site sees i'm Number 4939096 on Examplesite and can use that infomation to do http requests on my behalf. Then when they logout session 4939096 will be ended on my server. I'm building a API System and need something like this. I want to use cookies but told there not cross site. Is there anything i can do?