Forward Incoming SMS Messages Using Python

Overview

This guide shows how to forward SMS text messages received on your Plivo number, as you might want to do for someone who’s out of the office or who leaves the company.

You can forward SMS messages either by using our PHLO visual workflow builder or our APIs. Follow the instructions in one of the tabs below.

You can create and deploy a PHLO to forward an incoming message with a few clicks on the PHLO canvas.

How it works

Receive SMS

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 SMS. You can rent numbers from the Numbers page of the Plivo console, or by using the Numbers API.

Create the PHLO

To create a PHLO, visit the PHLO page of the Plivo console. If this is your first PHLO, the PHLO page will be empty.

Create a PHLO to forward SMS

  • Click Create New PHLO.

  • In the Choose your use case pop-up, click Build my own. The PHLO canvas will appear with the Start node.

    Note: The Start node is the starting point of any PHLO. It lets you trigger a PHLO to start upon one of three actions: incoming SMS message, incoming call, or API request.

  • From the list of components on the left-hand side, drag and drop the Send Message component onto the canvas. When a component is placed on the canvas it becomes a node.

  • Draw a line to connect the Start node’s Incoming Message trigger state to the Send Message node.

  • In the Configuration pane at the right of the canvas, configure the Send Message node with the phone number to which you want to forward the message.

  • Once you’ve configured the node, click Validate to save the configuration.

  • After you complete the configuration, give the PHLO a name by clicking in the upper left, then click Save.

Assign the PHLO to a Plivo number

Once you’ve created and configured your PHLO, assign it to a Plivo number.

  • On the Numbers page of the console, under Your Numbers, click the phone number you want to use for the PHLO.

  • In the Number Configuration box, select PHLO from the Application Type drop-down.

  • From the PHLO Name drop-down, select the PHLO you want to use with the number, then click Update Number.

Assign PHLO to a Plivo Number

Test

You can now send a message to your Plivo phone number and see how the inbound message is forwarded to the phone number you specified.

For more information about creating a PHLO application, see the PHLO Getting Started guide. For information on components and their variables, see the PHLO Components Library.

Here’s how to use Plivo APIs to forward incoming SMS text messages.

How it works

Forward SMS

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 SMS; 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 Python development environment and a web server and safely expose that server to the internet.

Create a Flask server to forward messages

Create a file called forward_sms.py and paste into it this code.

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from flask import Flask, request, make_response, Response
from plivo import plivoxml

app = Flask(__name__)

@app.route('/forwardsms/', methods=['GET', 'POST'])
def forward_sms():

    from_number = request.values.get('From')
    to_number = request.values.get('To')
    text = request.values.get('Text')
    print('Message received - From: {}, To: {}, Text: {}'.format(from_number,to_number,text))
    
    response = plivoxml.ResponseElement()
    response.add(
        plivoxml.MessageElement(
            text,
            src=to_number,  
            dst="<destination_number>"))
    print(response.to_string())  # Prints the XML
    # Returns the XML
    return Response(response.to_string(), mimetype='application/xml')

if __name__ == '__main__':
    app.run(host='0.0.0.0', debug=True)

Replace the destination number placeholder with an actual phone number in E.164 format (for example, +12025551234).

Add a route for the forwardsms function and expose your local server to the internet.

Create a Plivo application to forward messages

Associate the Flask 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 ours Forward SMS. Enter the server URL you want to use (for example https://<yourdomain>.com/forwardsms/) in the Message URL field and set the method to POST. Click Create Application to save your application.

Create 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 Forward SMS (the name we gave the application).

Click Update Number to save.

Assign Phone Number to Forward SMS App

Test

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