files_create

// 201 created

{
 "id":616,
 "url":"http://google.com",
 "convert_to":"pdf",
 "created_at":"2013-07-08T01:38:12Z",
 "status":"queued",
 "download_url":"",
 "notifications":[]
}

files_create_error

// 422 Unprocessable Entity
 
{"errors":
 {
  "url":["can't be blank"],
  "convert_to":["can't be blank"]
 }
}