The Pagination filter extracts segments matching /page/:page from the end of the recognized url and exposes the page parameter as params[:page]. When a url is generated the filter adds the segments to the url accordingly if the page parameter is passed to the url helper.

  incoming url: /products/page/1
  filtered url: /products
  params:       params[:page] = 1

You can install the filter like this:

  # in config/routes.rb
  Rails.application.routes.draw do
    filter :pagination
  end

To make your named_route helpers or url_for add the pagination segments you can use:

  products_path(:page => 1)
  url_for(:products, :page => 1)