An example script that counts the active subscribers in a Spreedly site using the transaction history.

active_subscriber_counter.rb

SITE = ARGV[0]
TOKEN = ARGV[1]

require 'rubygems'
require 'nokogiri'

def next_transactions(since=0)
  puts "Requesting transactions since #{since}"
  doc = Nokogiri::XML(`curl -s -S -u #{TOKEN}:X https://spreedly.com/api/v4/#{SITE}/transactions.xml?since_id=#{since}`)
  (doc/'transaction').collect do |t|
    {:id => (t/'id').first.content,
     :type => (t/'detail-type').first.content,
     :customer_id => (t/'subscriber-customer-id').first.content,
     :succeeded => (t/'succeeded').first.content}
  end
end

def process(transaction, subscribers)
  return unless transaction[:succeeded] == 'true'

  subscriber = subscribers[transaction[:customer_id]]
  case transaction[:type]
  when 'Subscription', 'ComplimentarySubscription', 'LifetimeComplimentarySubscription', 'Renewal'
    subscriber[:active] = true
  when 'Expiration', 'Cancellation'
    subscriber[:active] = false
  end
end

last = 0
subscribers = Hash.new{|h,k| h[k] = {}}
loop do
  transactions = next_transactions(last)
  break if transactions.empty?
  transactions.each do |transaction|
    process(transaction, subscribers)
  end
  last = transactions.last[:id]
end

currently_active = subscribers.values.select{|subscriber| subscriber[:active]}.size
puts "Currently active subscribers: #{currently_active}"

output

ntalbott@joshua:~/git/spreedly/tmp$ ruby active_subscriber_counter.rb [site] [token]
Requesting transactions since 0
Requesting transactions since 231501
Requesting transactions since 240493
Currently active subscribers: 64