The Constant Contact REST API currently supports the OAuth 2.0 authentication model. Basic Authentication is no longer supported, and we strongly encourage developers to switch to OAuth 2.0 as soon as possible. Both the Server and Client flows from the OAuth 2.0 spec are now supported, so developers can choose the best approach for their application.
NOTICE: As of August 22, 2014, the v1 XML API Images and Folder resources (endpoints) have been retired and are no longer available. Developers wishing to access library resources must now use the v2 API image and folder resources for this functionality. Please refer to the v2 Library image and folder documentation.
Constant Contact provides a set of APIs that expose functionality in our Event Marketing product. The events collection and its assoicated operations let developers view events, event details, and event registrants.
The Campaign Events service provides access to the detailed results (Open, Click, Bounce and other Events) associated with any Campaign (email) sent in the last 90 days. It helps answer these kinds of question: What Contacts Opened my last email? What links in the Campaign did they Click On? When did the Contact perform the action?