Following this discussion on the forum:

Active Pagination and Active Search

My lean approach

# app/controllers/concerns/pagination.rb

module Pagination
  extend ActiveSupport::Concern

  def default_per_page
    25
  end

  def page_no
    params[:page]&.to_i || 1
  end

  def per_page
    params[:per_page]&.to_i || default_per_page
  end

  def paginate_offset
    (page_no-1)*per_page
  end

  def paginate
    ->(it){ it.limit(per_page).offset(paginate_offset) }
  end
end

class ApplicationController < EvenMoreAbstractController
  include Pagination
end

Now, in controllers, you can call:

def index
	scope = Record.scoped
  scope.then(&paginate)
end

# which is a shortcut for

def index
	scope = Record.scoped
  scope.limit(per_page).offset(paginate_offset)
end

The params are :page and :per_page.

Current gems

kaminari

https://github.com/kaminari/kaminari

Creates .page scope on AR models. Okay.

User.page(1)