WhatsApp bot for currency conversion with Twilio service

Simple Whatsapp bot for currency conversion using Twilio service and ExchangeRate-API

Features

• Language detection of the incoming messages via fastText package
• Updated currency conversion values thanks to ExchanRate-API

Dependencies

• Developed with Python 3.7
• Flask, since we create a web application that reply to incoming WhatsApp messages
• ngrok, to connect the Flask application in the local system to a public URL that Twilio can connect to (needed in the development version at least, because the computer running the app is likely behind a router or firewall, so it isn’t directly reachable on the Internet)
• A smartphone with an active phone number and WhatsApp installed
• A Twilio account
• ExchangeRate-API API key.

Installation

To be able to run the python web application, you can install all dependencies automatically by running:

pip install requirements.txt

FastText distributes two models for language identification, which can recognize 176 languages, those are:

• lid.176.bin, which is faster and slightly more accurate, but has a file size of 126MB ;
• lid.176.ftz, which is the compressed version of the model, with a file size of 917kB.

In this project we use lid-176.bin. See Language identification in fastText website.

Usage

In order to make the bot works, you'll need a ExchangeRate-API API key. Once you get one, put it in a config.py python file in the project as follows:

API_KEY = "XXXXXXXXXXXXXXXXXXXXXX"

Twilio provides a WhatsApp sandbox, connect your smartphone to the sandbox. See Twilio resources and documentation for this.

Run the python web application:

python main.py

The service is now running as a private service on port 5000 in the local system and will sit there waiting for incoming connections.

In another shell, run ngrok to allocate a temporary public domain that redirects HTTP requests to our local port 5000.

ngrok http 5000

You'll get something like this:

Where the forwarding URL is something like https://XXXXXXXXXXX.ngrok.io.

Resources and bibliography

• Build a WhatsApp Chatbot With Python from Twilio Blog

Author and Institution

Gonzalo G. Fernández ggfernandez@unbosque.edu.co fernandez.gfg@gmail.com

Sistemas Inteligantes - Programa de Ingeniería de Sistemas - Universidad El Bosque, Bogotá, Colombia.