Good day,
I was wondering about official Plesk 12 support in Blesta. When I add a server in Blesta and select Plesk 11.5, it seems to work. So the API seems to be compatible.
The API documentation says: Every version of Plesk supports several versions of XML API that were released with and before this version of Plesk. For instance, Plesk 11.0 supports version 1.6.3.5 of XML API, and it is also compatible with versions 1.6.3.4 and earlier.
It might still be worth a look to see what they actually changed and make version 12 officially supported.
http://download1.parallels.com/Plesk/Doc/en-US/online/plesk-api-rpc/index.htm
Kind regards,
Job