On Github, there is a repository that provides a server-side extension (SSE) protocol based on gRPC that allows you to extend the Qlik built-in expression library with functionality from external calculation engines. Users can use external calculation engines in both load scripts and charts. In Qlik Sense and QlikView, the instance can connect to these server-side extensions (SSEs) by defining analytic connections.
This repository includes documentation that describes the SSE protocol, how to use it and how to build client customized plugins. Also included are examples written in a couple of different languages.
Resolution:
Qlik Server-Side Extension: https://github.com/qlik-oss/server-side-extension
Documentation:
Server side extensions syntax | Help.qlik.com (Qlik Cloud)
Analytic connections | Help.qlik.com (Qlik Sense on premise)
Overview and Considerations
Communication Flow
Guide to Certificates
Configuring SSE Plugins
Writing your own SSE Plugin
Protocol Documentation
Example Plugins
R-Plugin for connecting to R via RServe