mechanize

test.rb

require 'mechanize'
require 'json'

agent = Mechanize.new
headers = { 
  'X-Requested-With' => 'XMLHttpRequest',
  'Content-Type' => 'application/x-www-form-urlencoded',
  'Accept' => '*/*',
  'Cookie' => 'removed'
  }
params = {
  start: 0,
  limit: 19,
  sort: 'last_activity',
  dir: 'desc',
  filters: [{
    field: 'account',
    comparison: 'eq',
    value: 'something'
    }]
}.to_json
page = agent.post('https://top-secret-url', params, headers)

puts page.body