The Nutshell Python SDK by Emil Stenström allows API interaction and provides JSON-RPC protocol. Resources explain how to create an API key and a username to make calls. Documentation available at https://www.nutshell.com/api/detail/class_core.html
Handshake, sales order processing platform, offers the Handshake API that allows developers to integrate Handshake with third party applications and services. Handshake allows users to write, accept, and sync orders across any device or server running the Handshake platform. Additionally, Handshake supports barcode scanning for more streamlined order processing.