Google Apps Activity API

[Nick H]

I've been trying unsuccessfully to use the Google Apps Activity API to retrieve the activity on a specific file. The API is enabled within the Developer Console. However, whenever I try to execute the action against the API I receive the error below.

"error": {
    "code": 403, 
    "message": "Access Not Configured. Please use Google Developers Console to activate the API for your project.", 
    "errors": [
      {
        "domain": "usageLimits", 
        "message": "Access Not Configured. Please use Google Developers Console to activate the API for your project.", 
        "reason": "accessNotConfigured"
      }
    ]

  }

This is happening in the Oauth Playground, as well as in my C# application. All other Google APIs I'm using (Admin, Drive, Directory, etc) work fine. I haven't been able to find much discussion on this API. Are people using it, or is there another way to list a files activity that I'm missing? I've been using Revisions, but doesn't seem to list all the activity done by multiple users.

Thanks for any help.