trackings_controller.rb

class TrackingsController < ApplicationController
  def create
    @tracking = Tracking.create(tracking_params)
    render json: { success: true }
  end

private

  def tracking_params
    params.require(:tracking).permit(:ip, :url)
  end
end

class TrackingsController < ApplicationController
  def create
    data = tracking_params.merge(ip: request.remote_id)
    @tracking = Tracking.create(data)
    render json: { success: true }
  end

private

  def tracking_params
    params.require(:tracking).permit(:ip, :url)
  end
end

$('a').click (e) ->
  # exemplo: "http://www.icasei.com.br/sobre"
  url = e.currentTarget.href

  $.ajax
    url: '/trackings'
    method: 'POST'
    data:
      tracking:
        ip: url

$('a').click(function(e) {
  var url = e.currentTarget.href;
  $.ajax(url: '/trackings', method: 'POST', data: { tracking: { ip: url } });
});