How To Receive SMS Messages with Ruby on Rails

Using the Twilio Gem

Assuming you have a Twilio account and API credentials, add the following to your Gemfile:

gem 'twilio-ruby'

Alternatively you can gem install twilio-ruby.

To have Twilio send an incoming SMS to a particular route in your application, you need to configure the Messaging URL for your phone number. Once that’s done, you need to set up a route in config/routes.rb:

TwilioSample::Application.routes.draw do
  resources :messages
end

This creates a set RESTful routes (GET /messages to list messages, POST /messages to create a message, etc.) that will send requests to the MessagesController. With these routes defined, you would set the Messaging URL in the Twilio dashboard to https://your.site/messages as an HTTP POST Webhook.

Your controller handles the message:

class MessagesController < ApplicationController

  def create
    # First, check to see if this message really came from Twilio
    uri, signature = [request.protocol, request.host_with_port, request.path].join, request.env['HTTP_X_TWILIO_SIGNATURE']
    validator = Twilio::Util::RequestValidator.new(ENV['TWILIO_AUTH_TOKEN'])
    
    if validator.validate(uri, request.request_parameters, signature)
      # The params hash has the data from the Twilio payload
      Rails.logger.info "I just got this message from #{params[:From]}: #{params[:Body]}"

      # Send back a response that Twilio can handle
      render xml: { Sms: "Thanks, I got your message" }.to_xml(root: 'Response')

    else
      # This request didn't come from Twilio, so return a "Forbidden" response
      head(403)
    end

  end

end