How to sell a script?

Question

PHP

There is PHP code showing the current phase of the moon, horoscope and so on in the form of a widget (like those social media polls). I'd like to provide code to add to the sources with a unique link to the buyer's site, something like this:

<?php require_once ("http://domain.com/api/moon.php"); 
...
moon_api($date);
?>

And after that, for example, my moon successfully appears in the left column of the site. And so, the question is: how to protect the code from unscrupulous copy-pasters (perhaps you just need to transfer the source?) and how can it be safely sold to both parties?

Answer 1

sell access to api, what's wrong with that. To access api, let's say you need to create an account on your service and get an access token.

Answer 2

There is a solution - to encode with a yoncube.
be careful: in principle, it will be decoded, but not very cheaply, so first (before encoding) try to obfuscate.
It's like an alternative to API distribution.