Well look I have a multisite.
The main site that uses the sites/all folder for its modules and libreries and another subdomain that uses sites/subdomain for its modules, themes, etc...
they are in separate databases but share the same drupal instance
In the main site I have an inventory app for a local store they manage their inventory and their invoices there.
In the subdomain I did a ecommerce store so they will sell their products through that subdomain, I need that when an user buys a product in the ecommerce store ten automatically I need that purchase to be registered in the inventory that is in the other site.
How to do this connection betweed the 2 sites in a multisite config?
Thanks for your help