Is there a function keep track of theme installation ?

no.

anyone who can build something like this? I’m ready to pay for it

Unless you are doing this with blogs that you are hosting ..that that what you are asking for borders on malicious…you know that right?

there is no reason for a theme used in a stand alone version of WP to “phone home”.

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further to this, you appear to be using MU .. they have their own forums, and arguably someone over there might have already done something like that.

https://mu.www.ads-software.com/forums/

I am creating themes on closed circuit and licenses go for 1 domain only so what I want is to see if clients “pass” the themes to their friends

yes well thats malicious. Putting code into a theme that sends an email using someone else’s server resources is malicious, especially when Im sure you wont be telling anyone.

How about I expand on that idea, and put in some code to send out emails that contain a ton of links to viagra sites to 1000 ppl on gmail?

malicious.

In fact, thats so malicious, its my blog fodder for the night. Questions like that is one of the reasons why ppl need to be wary of the themes they use – the fact is you never really know what ppl put inside those themes, epsecially if you never look.

Ok, thank you.
You made me rethink my idea, so I’ll do another thing instead… I’m gonna make a little script that will check the website URL and if it matches the variable I set before I sell out the theme it will work if not it will show some blank page.
Thanks for your suggestions whooami

good, glad to hear it ??