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Twilio SMS Python Quickstart

With just a few lines of code, your Python application can send and receive text messages with Twilio Programmable SMS.

This Python SMS Quickstart will teach you how to do this using our Communications REST API, the Twilio Python helper library, and Python’s Flask microframework to ease development. Prefer to use Django? Check out this blog post.

In this Quickstart, you will learn how to:

  1. Sign up for Twilio and get your first SMS-enabled Twilio phone number
  2. Set up your development environment to send and receive messages
  3. Send your first SMS
  4. Receive inbound text messages
  5. Reply to incoming messages with an SMS

Prefer to get started by watching a video? Check out our Python SMS Quickstart video on Youtube.

Show me how it's done!

If you already have a Twilio account and an SMS-enabled Twilio phone number, you’re all set here! Feel free to jump to the next step.

Before you can send an SMS from Python, you'll need to sign up for a Twilio account or sign into your existing account and purchase an SMS-capable phone number.

You can sign up for a free Twilio trial account here.

  • When you sign up, you'll be asked to verify your personal phone number. This helps Twilio verify your identity and also allows you to send test messages to your phone from your Twilio account while in trial mode.
  • Once you verify your number, you'll be asked to create a project. For the sake of this tutorial, you can click on the "Learn and Explore" template. Give your project a name, or just click "skip remaining steps" to continue with the default.
  • Once you get through the project creation flow, you'll arrive at your project dashboard in the Twilio Console. This is where you'll be able to access your Account SID, authentication token, find a Twilio phone number, and more.

If you don't currently own a Twilio phone number with SMS functionality, you'll need to purchase one. After navigating to the Buy a Number page, check the "SMS" box and click "Search."

Buy a SMS-Capable Twilio Phone Number

You’ll then see a list of available phone numbers and their capabilities. Find a number that suits your fancy and click "Buy" to add it to your account.

Select an SMS-enabled phone number

Now that you have a Twilio account and a programmable phone number, you can start writing some code! To make things even easier, we'll next install Twilio's official helper library for Python applications.

No problem! Take me through the setup.

If you’ve gone through one of our other Python Quickstarts already and have Python and the Twilio Python helper library installed, you can skip this step and get straight to sending your first text message.

To send your first SMS, you’ll need to have Python and the Twilio Python helper library installed.

Install Python

If you’re using a Mac or Linux machine, you probably already have Python installed. You can check this by opening up a terminal and running the following command:

python --version

You should see something like:

$ python --version
Python 3.4  # Python 2.7+ is okay too

Windows users can follow this excellent tutorial for installing Python on Windows, or follow the instructions from Python's documentation.

Twilio’s Python server-side SDK supports both Python 2 and Python 3. You can use either version for this quickstart, but we recommend using Python 3 for future projects with Twilio unless there are specific libraries your project needs which are only compatible with Python 2.

Install the Twilio Python Server-side SDK

The easiest way to install the library is using pip, a package manager for Python that makes it easier to install the libraries you need. Simply run this in the terminal:

pip install twilio

If you get a pip: command not found error, you can also use easy_install by running this in your terminal:

easy_install twilio

If you'd prefer a manual installation, you can download the source code (ZIP) for twilio-python and then install the library by running:

python setup.py install

in the folder containing the twilio-python server-side SDK library code.

All set! Let's send a text message.

Send an outbound SMS with Python

Now that we have Python and twilio-python installed, we can send an outbound text message from the Twilio phone number we just purchased with a single API request. Create and open a new file called send_sms.py and type or paste in this code sample.

        This code creates a new instance of the Message resource and sends an HTTP POST to the Messages resource URI.

        Send an SMS Using Twilio

        This code creates a new instance of the Message resource and sends an HTTP POST to the Messages resource URI.

        You’ll need to edit this file a little more before your message will send:

        Replace the placeholder credential values

        Swap the placeholder values for account_sid and auth_token with your personal Twilio credentials. Go to https://www.twilio.com/console and log in. On this page, you’ll find your unique Account SID and Auth Token, which you’ll need any time you send messages through the Twilio Client like this. You can reveal your auth token by clicking on the 'view' link:

        Reveal your Auth Token in the Twilio Console

        Open send_sms.py and replace the values for account_sid and auth_token with your unique values.

        Please note: it's okay to hardcode your credentials when getting started, but you should use environment variables to keep them secret before deploying to production. Check out how to set environment variables for more information.

        Replace the from_ phone number

        Remember that SMS-enabled phone number you bought just a few minutes ago? Go ahead and replace the existing from_ number with that one, making sure to use E.164 formatting:

        [+][country code][phone number including area code]

        Replace the to phone number

        Replace the to phone number with your mobile phone number. This can be any phone number that can receive text messages, but it’s a good idea to test with your own phone so you can see the magic happen! As above, you should use E.164 formatting for this value.

        If you are on a Twilio Trial account, your outgoing SMS messages are limited to phone numbers that you have verified with Twilio. Phone numbers can be verified via your Twilio Console's Verified Caller IDs.

        When you send an SMS from your free trial phone number, it will always begin with "Sent from a Twilio trial account." We remove this message after you upgrade.

        Save your changes and run this script from your terminal:

        python send_sms.py

        That's it! In a few moments, you should receive an SMS from your Twilio number on your phone.

        Are your customers in the U.S. or Canada? You can also send them MMS messages by adding just one line of code. Check out this guide to sending MMS to see how it's done.

        I got the message! What’s next?

        Install Flask and set up your development environment

        In order to receive and reply to incoming SMS messages, we'll need to create a very lightweight web application that can accept incoming requests. We'll use Flask for this Quickstart, but if you prefer to use Django, you can find instructions in this blog post.

        For instructions on setting up Flask on Windows, you can check out this handy guide.

        Install Pip and Virtualenv

        To install Flask and set up our development environment, we’ll need two tools: pip to install Flask and virtualenv to create a unique sandbox for this project. If you already have these tools installed, you can skip this section.

        Pip comes pre-packaged with Python 3.4+, so if you’re on a recent version of Python, you don’t need to install anything new. If you’re on an earlier version, never fear: pip is included in virtualenv. So let’s install virtualenv!

        If you’re using Python 2.4, run the following command in your terminal:

        easy_install virtualenv

        If you’re using Python 2.5-2.7, run the following command in your terminal, specifying your version number:

        easy_install-2.7 virtualenv

        Replace the 2.7 with 2.5 or 2.6 if you have that version installed.

        To install virtualenv with Python 3.4+:

        # If you get 'permission denied' errors try running "sudo python" instead of "python"
        pip install virtualenv

        If you get any errors in this step, check out these tips for debugging.

        Create and activate your virtual environment

        Once you have virtualenv installed, use your terminal to navigate to the directory you’re using for this Quickstart and create a virtual environment:

        cd Documents/my_sms_quickstart_folder
        virtualenv --no-site-packages .

        Now, activate the virtual environment:

        source bin/activate

        You can verify that your virtualenv is running by looking at your terminal: you should see the name of the enclosing folder. It will look something like this:

        (sms_quickstart)USER:~ user$

        If you wish to point your virtual environment to a Python version that’s different from your default or just want to learn more about virtualenv, see this thorough guide.

        Install dependencies

        Now we’re ready to install Flask. Create a file called requirements.txt and add the following lines to it:


        Then install both of these packages with pip in your terminal:

        bin/pip install -r requirements.txt

        Test everything from scratch

        First, make sure your virtualenv is activated:

        cd Documents/my_sms_quickstart_folder
        source bin/activate     # On Windows, use .\bin\activate.bat

        Then, create and open a file called run.py and add these lines:

        from flask import Flask
        app = Flask(__name__)
        def hello():
            return "Hello World!"
        if __name__ == "__main__":

        Now it's time to try running it. In your terminal, type:

        python run.py

        You should see:

        * Running on

        Navigate to http://localhost:5000/sms in your browser. You should see a "Hello World!" message. You’re ready to create your first Twilio messaging app!

        If you encountered any issues or want instructions on setting up your environment with an older Python version (<3.4), check out our full guide to setting up a local Python dev environment.

        I'm set up. Show me how to let Twilio reach my application!

        Allow Twilio to talk to your Flask application

        We’re about to build a small Flask application to receive incoming messages. Before we do that, we need to make sure that Twilio can reach your application.

        Most Twilio services use webhooks to communicate with your application. When Twilio receives an SMS, for example, it reaches out to a URL in your application for instructions on how to handle the message.

        When you’re working on your Flask application in your development environment, your app is only reachable by other programs on your computer, so Twilio won’t be able to talk to it. We need to solve this problem by making your application accessible over the internet.

        While there are a lot of ways to do this, like deploying your application to Heroku or AWS, you'll probably want a less laborious way to test your Twilio application. For a lightweight way to make your app available on the internet, we recommend a tool called Ngrok. Once started, Ngrok provides a unique URL on the ngrok.io domain which forwards incoming requests to your local development environment.

        It works something like this:

        How ngrok helps Twilio reach your local server

        If you don’t already use Ngrok, head over to their download page and grab the appropriate binary for your operating system. Once downloaded, unzip the package.

        If you're working on a Mac or Linux, you're all set. If you're on Windows, follow our guide on how to install and configure ngrok on Windows. For more info on ngrok, including some great tips and tricks, check out this in-depth blog post.

        Once downloaded, start that Hello World application we made previously:

        python run.py

        Your local application must be running locally for Ngrok to do its magic.

        Then open a new terminal tab or window and start Ngrok with this command:

        ./ngrok http 5000

        If your local server is running on a different port, replace 5000 with the correct port number.

        You should see output similar to this:

        Ngrok server terminal output

        Copy your public URL from this output and paste it into your browser, appending our /sms route to the ngrok URL. You should see your Flask application's "Hello, World!" message.

        My server is publicly accessible. Teach me how to receive messages!

        Receive and reply to inbound SMS messages with Flask

        When someone sends an SMS to your Twilio phone number, Twilio makes an HTTP request to your server asking for instructions on what to do next. Once you receive the request, you can tell Twilio to reply with an SMS, kick off a phone call, store details about the SMS in your database, or trigger something else entirely - it’s all up to you!

        For this Quickstart, we’ll have our Flask app reply to incoming SMS messages with a thank you to the sender. Open up run.py again and update the code to look like this code sample:

              When your phone number receives an incoming message, Twilio will send an HTTP request to your server. This code shows how your server should respond to reply with a text message.

              Reply to an incoming message using Twilio SMS

              When your phone number receives an incoming message, Twilio will send an HTTP request to your server. This code shows how your server should respond to reply with a text message.

              Save this file and restart your app with

              python run.py

              Double-check that Ngrok is still running on your localhost port. Now Twilio will be able to find your application - but first, we need to tell Twilio where to look.

              Configure your webhook URL

              For Twilio to know where to look, you need to configure your Twilio phone number to call your webhook URL whenever a new message comes in.

              1. Log into Twilio.com and go to the Console's Numbers page.
              2. Click on your SMS-enabled phone number.
              3. Find the Messaging section. The default “CONFIGURE WITH” is what you’ll need: "Webhooks/TwiML".
              4. In the “A MESSAGE COMES IN” section, select "Webhook" and paste in the URL you want to use. Make sure to add the /sms route to the end of your ngrok URL here:

              Configure your SMS Webhook

              Save your changes - you’re ready!

              Test your application

              As long as your localhost and the Ngrok servers are up and running, we’re ready for the fun part - testing our new Flask application!

              Send a text message from your mobile phone to your Twilio phone number. You should see an HTTP request in your Ngrok console. Your Flask app will process the text message, and you’ll get your response back as an SMS.

              It worked! All done - what's next?

              Where to next?

              Now that you know the basics of sending and receiving SMS and MMS text messages with Python, you might want to check out these resources.

              We can't wait to see what you build!

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              Need some help?

              We all do sometimes; code is hard. Get help now from our support team, or lean on the wisdom of the crowd browsing the Twilio tag on Stack Overflow.