The Customer.io PHP Sample Code by Customer.io demonstrates API interaction, providing code to identify customers and track a customized event. Additional examples available at https://github.com/customerio/customerio-php/
Twilio has introduced the Twilio Proxy API, a new API for building private text and voice conversations between customers and mobile workers. The company also announced the new Twilio Engagement Cloud, a suite of Declarative APIs with additional business process and logic built in.
Nexmo's mission is to take SMS global, putting messages on the 5 billion smartphones across continents and languages, with 800 carriers in 200 countries. As Alex Williams noted in Techcrunch, Nexmo raised $3 million from Intel Capital, NHN Investment Corporation and Initial Capital. Nexmo is:
"one of a new generation of companies that are disrupting the telco market. It streamlines the layers between the telcos and developers, removing the hubs by offering a carrier grade service based upon a worldwide network that gives companies like Airbnb an international messaging platform for communicating between buyers and sellers over SMS."
The RESTful and SMPP APIs save large multinationals from having to build their own infrastructure.