package a script called by http in a plugin way

I’d suggest that you start with Writing_a_Plugin.

Hi, thanks for your answer.
I’ll try to be more precise.

I have already read this resource and know how to write my own (very basic) plugin.

I have developed a script which instantiate an XML RPC client to synchronise content between 2 wordpress instances.

I perform HTTP requests to run this script : https://mywpinstance.com/myscript.php

now I would like to package it as a plugin.

To perform this, I think I’m gonna try adding a rewrite rule,
I will call : https://mywpinstance.com/myscript.php which will execute the code of https://mywpinstance.com/wp-content/plugins/myplugin/myplugin.php

Hope this will work !