Send an SMS during a phone call. Powered by Twilio and Python/Flask

This template is part of Twilio CodeExchange. If you encounter any issues with this code, please open an issue at github.com/twilio-labs/code-exchange/issues.

About

Learn how to send an SMS to someone who's called your Twilio phone number while they're on the call.

This small sample application will say a short message to an inbound caller and, at the same time, send them an SMS.

Read the full tutorial here!

Implementations in other languages:

.NET	Java	Node	PHP	Ruby
Done	Done	Done	Done	Done

Features

• Flask web framework
• Twilio Python Helper Library
• Unit tests using pytest

Set up

Requirements

• Python >= 3.6.x version

Twilio Account Settings

You need to collect all the config values to run the application.

Config Value	Description
TWILIO_ACCOUNT_SID / TWILIO_AUTH_TOKEN	In Twilio Account Settings.

Local development

1. First clone this repository and cd into it.

   git clone https://github.com/TwilioDevEd/send-sms-during-inbound-calls-python.git
   cd send-sms-during-inbound-calls-python

2. Create the virtual environment, load it and install the dependencies.

   make install

   If you're using a Windows machine, you'll activate your environment in one of two ways:

   PowerShell: . .\venv\Scripts\activate.ps1

   Cmd shell: .\venv\Scripts\activate.bat

3. Copy the sample configuration file and edit it to match your configuration.

   cp .env.example .env

   See Twilio Account Settings to locate the necessary environment variables.

4. Start the server, the following command will run the application on port 5000. Before running the following command, make sure the virtual environment is activated.

   make serve

5. Expose the application to the wider Internet using ngrok.

   ngrok http 5000 -host-header="localhost:5000"

6. Configure Twilio to call your webhooks

   You will need to configure Twilio to call your application when calls are received in your Twilio Number. The voice url should look something like this:

   https://0f72e8a8.ngrok.io/answer
   

7. Finally, call your Twilio number to test it out.

That's it!

Docker

If you have Docker already installed on your machine, you can use our docker-compose.yml to setup your project.

1. Make sure you have the project cloned.
2. Setup the .env file as outlined in the Local Development steps.
3. Run docker-compose up.
4. Follow the steps in Local Development on how to expose your port to Twilio using a tool like ngrok and configure the remaining parts of your application.

Tests

To run the tests locally, execute the following command. Before running the following command, make sure the virtual environment is activated.

python3 -m pytest

Cloud deployment

Additionally to trying out this application locally, you can deploy it to a variety of host services. Here is a small selection of them.

Please be aware that some of these might charge you for the usage or might make the source code for this application visible to the public. When in doubt research the respective hosting service first.

Service
Heroku

Resources

• The CodeExchange repository can be found here.

Contributing

This template is open source and welcomes contributions. All contributions are subject to our Code of Conduct.

Visit the project on GitHub

License

MIT

Disclaimer

No warranty expressed or implied. Software is as is.