We’ve just released v2beta1 of the 
DoubleClick Ad Exchange Buyer REST API. Unlike previous releases, this is an early access open beta that only allows three new resources—
Clients, 
Invitations, and 
Users. In order to access this version, new users will need to go to the API Manager in the 
Google Developers Console and enable “Ad Exchange Buyer API II”; current users will have this enabled automatically. For access to existing resources such as Accounts or Creatives, you should continue using 
v1.4.
The new resources available in this release allow you to add and manage clients programmatically rather than through the 
Ad Exchange UI. A 
Client represents an advertiser, agency, or brand that can view, negotiate, and/or approve deals in areas of the Ad Exchange UI related to the 
Marketplace. You can send 
Invitations on behalf of a Client to add 
Users—the individuals accessing the UI as the Client.
To get even more familiar with these new resources, check out the 
Client Access Overview. There are some subtle differences when using the 
client libraries with this version, so we recommend that you look at our 
samples for guidance on initializing clients and making API calls. At this time, the 
Java, 
PHP, and 
Python samples have been updated for compatibility with this version and the others are planned for the near future. If you have any questions or feedback related to these changes, feel free to reach out to us at the 
DoubleClick Ad Exchange Buyer API forums or the 
Ad Developers Google+ Page.
 - Mark Saniscalchi, DoubleClick Ad Exchange Team
 - Mark Saniscalchi, DoubleClick Ad Exchange Team