Here is a simple wrapper for working with the Campaign Monitor API. I haven't tested all the API methods, but it's pretty simple.
https://github.com/calvinfroedge/FuelPHP---CampaignMonitor-API-Package
To use, you just do:
CampaignMonitor::api_method('GET');
or
CampaignMonitor::api_method('POST', 'param', 'param', $params, $query_string_params);
If it's a string it just chains it onto the method...ie api_method/param/param
If it's an array it puts it in the CURLOPT_POSTFIELDS array, and if it's an array with a key of 'qs_params', it adds those params to a query string after the endpoint ie ?email=myemail@something.com?name=calvin
I tested with three API methods I personally needed to use...get lists, create subscriber, update subscriber, but I imagine it should work for just about all of them.
If there are any problems it is probably in the response handling (breaking up strings can be kind of messy).
Hope this is helpful to someone! Seemed a better option to me than working with the SDK.
Not sure that anyone uses this - but had a good go at upgrading the the \Response Curl implimentation as I was having trouble with parsing of data. I have also used \Format to parse the data. So far this has worked for what I have needed.