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Overview

You may want to have an application dial out for someone, so that it calls them on their phone, then connects them to the number they want. This involves three tasks:
  1. Make an outbound call to a caller.
  2. When the call recipient answers the phone, place a new call to a different number (second user).
  3. Bridge the calls (first and second user) after the second user answers.
Common use cases for this practice include click to call, where a server application directs a call to a person who clicks on a web link, then connects them with a company representative. This guide shows how to code connecting a user to second person on the Plivo platform, either by using our PHLO visual workflow builder or our APIs and XML documents. Follow the instructions in one of the tabs below.
Here‘s how to connect a call to a second person using XML.

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Prerequisites

To get started, you need a Plivo account — sign up with your work email address if you don’t have one already. You must have a voice-enabled Plivo phone number to receive incoming calls; 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.

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Create a Rails controller to connect calls to a second person

Change to the project directory and run this command to create a Rails controller for inbound calls.
rails generate controller Plivo voice
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/voice.html.erb
Edit app/controllers/plivo_controller.rb and add this code in the PlivoController class.
include Plivo
include Plivo::XML
include Plivo::Exceptions

class PlivoController < ApplicationController
	def outbound_call
		api = RestClient.new('<auth_id>','<auth_token>')
		response = api.calls.create(
			'<caller_id>',
			['<destination_number>'],
			'https://'+request.host+'/plivo/connect',
			{answer_method:'GET'}
		)
		render json: response.to_s
	end

	def connect
		response = Response.new
		response.addSpeak('Please wait while we connect your call')
		dial = response.addDial()
		dial.addNumber('<second_number>') # Dial to second number
		xml = PlivoXML.new(response)
		render xml: xml.to_xml
	end
end
Replace the auth placeholders with your authentication credentials from the Plivo console. Replace the phone number placeholders with actual phone numbers (for example, 12025551234).
Note: We recommend that you store your credentials in the auth_id and auth_token environment variables, to avoid the possibility of accidentally committing them to source control. If you do this, you can initialize the client with no arguments and Plivo will automatically fetch them from the environment variables. You can use ENV to store environment variables and fetch them when initializing the client.

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Add a route

Add a route for the inbound function in the PlivoController class. Edit the config/routes.rb file and add these lines.
  get 'plivo/outbound_call'
  get 'plivo/connect'
Start the Rails server.
rails server
You should see your basic server application in action at http://localhost:3000/plivo/outbound_call/.Set up ngrok to expose your local server to the internet.

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Test

Have your application make a call to a regular mobile phone. Plivo will send a request to your answer URL requesting a valid XML response and connect the call to a second user.