How to Receive and Respond to Incoming MMS Messages in Ruby with Rails and Plivo

Overview

This guide shows how to receive and automatically respond to incoming MMS messages on a Plivo number, as you might want to do for someone who’s out of the office or who leaves the company.

Here’s how to use Plivo’s SMS APIs to build this use case.

Prerequisites

To get started, you need a Plivo account — sign up with your work email address if you don’t have one already. To receive incoming messages you must have a Plivo phone number that supports MMS; you can rent numbers from the Numbers page of the Plivo console or by using the Numbers API. If this is your first time using Plivo APIs, follow our instructions to set up a Ruby development environment and a web server and safely expose that server to the internet.

Create a Rails server to receive MMS messages

Change to the project directory and run this command to create a Rails controller for inbound messages.

$ rails generate controller Plivo sms

This command generates a controller named plivo_controller in the app/controllers/ directory and a respective view in the app/views/plivo directory. We can delete the view as we don’t need it.

$ rm app/views/plivo/sms.html.erb

Create the autoresponder application using Rails server

Edit app/controllers/plivo_controller.rb and paste into it this code.

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include Plivo
include Plivo::Exceptions
include Plivo::XML

class PlivoController < ApplicationController
  skip_before_action :verify_authenticity_token
  def receive-mms
		from_number = params[:From]
		to_number = params[:To]
		text = params[:Text]
		media_url = params[:Media0]
      	puts "Message received - From: #{from_number}, To: #{to_number}, Text: #{text}, Media: #{media_url}"

		if text.downcase == "hi"
			text = "Hello!"
	   		media = ["https://media.giphy.com/media/888R35MJTmDxQfRzfS/giphy.gif"]
		elsif text.downcase == "bye"
			text = "Bye and have a nice day!"
			media = ["https://media.giphy.com/media/QM5lHSyFjz1XW/giphy.gif"]
		else
		    text = "I'm glad that we connected"
	        media = ["https://media.giphy.com/media/888R35MJTmDxQfRzfS/giphy.gif"]
		end
		
		api = RestClient.new("<auth_id>","<auth_token>")
		response = api.messages.create(
		src:to_number,
		dst:from_number,
		text:body,
		media_urls: media,
		type: "mms"
  )
  	render json: response.to_s
	end
end

Add a route

Edit config/routes.rb and change the line

Rails.application.routes.draw do
  get 'plivo/sms' 
end

to

Rails.application.routes.draw do
  post 'plivo/receive-mms/' => 'plivo#receivemms'
end

Test

Start the Rails server

$ rails server

You should see your basic server application in action at http://localhost:3000/plivo/receive-mms/.

Replace the auth placeholders with your authentication credentials from the Plivo console

Expose your local server to the internet.

Create a Plivo application

Associate the Rails server you created with Plivo by creating a Plivo application. Visiting Messaging > Applications and click Add New Application. You can also use Plivo’s Application API.

Give your application a name — we called our Receive-MMS. Enter the server URL you want to use (for example https://<yourdomain>.com/receive-mms/) in the Message URL field and set the method to POST. Click Create Application to save your application.

Assign a Plivo number to your application

Navigate to the Numbers page and select the phone number you want to use for this application. From the Application Type drop-down, select XML Application. From the Plivo Application drop-down, select Respond-MMS (the name we gave the application).

Click Update Number to save.

Test

Send a text message to the Plivo number you specified using any phone. The message should be replied to the destination number you specified.

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