The Help Scout Ruby Library by Hector Ramos in beta stage helps to access the API features of fetching users, mailboxes, customers, and conversations. API required available at http://developer.helpscout.net/
Rebel is known for its interactive emails. But, developers had asked for Rebel to launch an API that allowed them to build emails with JSON (same process as Rebel Actionable API) without the need for interactive functionality. In response, Rebel has launched the Rebel Lite API.
Twilio has launched Twilio Flex, a cloud-based contact center platform that is fully programmable and allows businesses to engage with customers via a variety of channels. Twilio Flex is currently in preview and the company plans on making the platform generally available by the end of 2018.