Build a WhatsApp Chatbot with PHP, Mezzio, and Twilio

A chatbot is a software application that enables conversation between humans and computers, either in written or spoken form. A simple chatbot can only answer limited questions, while others use artificial intelligence (AI) and machine learning (ML) to interact more human-like. The tutorial on building a WhatsApp chatbot with PHP, Mezzio, and Twilio uses the Weather API to retrieve the current weather forecast for any city around the world. The chatbot receives user input through Twilio's WhatsApp service, queries the Weather API, and sends back a nicely formatted response to the user, including temperature, humidity, wind speed, and other relevant details. To develop this chatbot, one needs PHP 7.4, a free Twilio account, Composer installed globally, ngrok, a smartphone with an active phone number and WhatsApp installed, and configuration of the Twilio WhatsApp Sandbox. The application is then built using Mezzio Skeleton, with the required dependencies installed, environment variables registered, and the chatbot's logic implemented using PHP. The chatbot can be started by running Composer serve and ngrok in separate terminal windows, and tested by sending a message to the Twilio number containing the name of the city for which the weather report is needed.