This quickstart will teach you to use Smooch's REST API, a Web messenger widget on a Website, and and some server-side code to create an auto response for when people send your business messages.
You should be able to follow along in node.js, or another programming language; you should also have ngrok (which creates secure tunnels to localhost), or be otherwise able to deploy a server; and you should have already signed up for a Smooch account.
First we'll set up a Web server: