- config layout. xml? e.g.
...
<disk type="gpt" name="sda">
  <part size="50%" name="/" format="8303" />
  <part size="40%" name="/home" format="8302" />
  <part size="5%" name="swap" format="8200" />
  <part size="5%" name="/boot" format="ef02" />
</disk>
...

-use sgdisk? scripting (generated by python) for disk partitioning (part types listed at http://www.rodsbooks.com/gdisk/walkthrough.html )

-support serverside "autoconfig"- a mechanism to let servers automatically generate xml build configs. e.g.:
  kernel ... aif_url="https://build.domain.tld/aif-ng.php" auto=yes
would yield the *client* sending info via URL params, e.g.
  https://build.domain.tld/aif-ng.php?disk[]=sda&disk[]=sdb&disk[sda]=300GB&disk[sdb]=500GB
? something like that.