How do I add containers programmatically v.9

I’ trying to rebuild our v.8 theme into v.9. I’m all excited about the container feature. I was able to integrate containers manually. But how to include it on install? Does it go in the controller of the theme or into the pagetheme. I have basic programming knowledge in PHP.
Thanks in advance.

Here is the basic documentation link (I’m guessing you already have this) Set Up your First Container :: Concrete CMS

Here is the XML that I used upon package install

<?xml version="1.0"?>
<concrete5-cif version="1.0">
            name="Container Display Name"

Thanks Hutman,
That should work, I’ll try that!
I just wonder if it would also possible via controller, like installing page templates.

The dashboard page for adding is at

At a guess, similar code in a package controller may work. You probably also need to set the package.

Maybe there is a simpler interface than that, like there is for adding page types or pages. Or maybe that is wishful thinking :scream: