use vessel as an alternative to kimurai: https://github.com/rubycdp/vessel

vessel.rb

require 'bundler/inline'

gemfile do
  source 'https://rubygems.org'
  gem 'vessel', github: 'rubycdp/vessel'  # commit 3097da3daeb2b0f06182b2d4faa7693d82407538
end

class FirstMiddleware < Vessel::Middleware
  def call(item, _)
    item[:h1] += '!'
    puts item[:h1]
    item
  end
end

class SecondMiddleware < Vessel::Middleware
  def call(item, _)
    puts item[:h1] + '!'
    item
  end
end

class ApplicationCrawler < Vessel::Cargo
  delay 1
  threads max: 1

  middleware 'FirstMiddleware', 'SecondMiddleware'
end

class ExampleCrawler < ApplicationCrawler
  start_urls 'https://example.com/'

  def parse
    yield({ h1: at_css('h1').text })
  end

  def parse2
    p data
  end
end

# run (kimurai: crawl!)
ExampleCrawler.run

# parse (kimurai: parse!)
engine = Vessel::Engine.new(ExampleCrawler)
engine.parse 'https://example.com/2', :parse2, { foo: :bar }