So the older environments ran thru SOAP commands. You can get the SDK for 2.1 here - http://software.intel.com/sites/manageability/AMT_Implementation_and_Reference_Guide/default.htm?turl=WordDocuments%2Fabouttheintelamtsdk.htm
You can build a SOAP query using something like Soapscope by MindReef - load up the libraries and chain the commands together to log into a system to call the inventory and log out. Remember you will need to have the system provisioned so your login credentials are valid.
it should be noted that iAMT actually is only a transport of the HW inventory and that it pulls this information for the SMbios table in the BIOS - so the alternate method is to pull the data using any standard SMBus tool you can find on the Internet.