gc.rb

require 'net/http'
require 'net/https'

url = URI.parse('https://checkout.google.com/api/checkout/v2/checkoutForm/Merchant/1234567890')
req = Net::HTTP::Post.new(url.path)

req.set_form_data({'my'=>'params'})
res = Net::HTTP.new(url.host, url.port)
res.use_ssl = true

#send the response to stderr for debugging
res.set_debug_output $stderr

res.start {|http| http.request(req) }