RestKit primary key attribute
As of the latest RESTKit version (0.23.2) you can define the primary key like this:
[_mapping addAttributeMappingsFromDictionary:@{ @"id" : @"objectId", @"name" : @"name" }];[_mapping setIdentificationAttributes:@[ @"objectId" ]];
Whereas objectId is you primary key on the core data object.