gem 'tbk'

TBK.configure do |config|
  config.commerce_id YOUR_COMMERCE_ID
  config.commerce_key YOUR_RSA_KEY

  # When certifying with Transbank you'll need to use the official logger
  config.webpay_logger :official do |logger|
    # On this path will be the config file and logs in the KCC format.
    logger.directory Rails.root.join('log/webpay')
  end
end

class WebpayController < ApplicationController

  # ...

  # Start a payment
  def pay
    # Setup the payment
    @payment = TBK::Webpay::Payment.new({
      request_ip: request.ip,
      amount: ORDER_AMOUNT,
      order_id: ORDER_ID,
      success_url: webpay_success_url,
      # Webpay can only access the HTTP protocol to a direct IP address (keep that in mind)
      confirmation_url: webpay_confirmation_url(host: SERVER_IP_ADDRESS, protocol: 'http'),

      # Optionaly supply:
      session_id: SOME_SESSION_VALUE,
      failure_url: webpay_failure_url # success_url is used by default
    })

    # Redirect the user to Webpay
    redirect_to @payment.redirect_url
  end

  # ...
end

class WebpayController < ApplicationController

  # ...

  # Confirmation callback executed from Webpay servers
  def confirmation
    # Read the confirmation data from the request
    @confirmation = TBK::Webpay::Confirmation.new({
      request_ip: request.ip,
      body: request.raw_post
    })

    if # confirmation is invalid for some reason (wrong order_id or amount, double payment, etc...)
      render text: @confirmation.reject
      return # reject and stop execution
    end

    if @confirmation.success?
      # EXITO!
      # perform everything you have to do here.
    end

    # Acknowledge payment
    render text: @confirmation.acknowledge
  end

  # ...

end