With QGIS 3 and the processing module refactoring, it is easiest to add tools without the complexity of plugins.

We will discuss the way to add algorithms in python to QGIS and the advantage of using processing. We will also discuss the limit and future of processing modules. As described by Victor Olaya in 2016 during the 2nd International QGIS Conference, all the QGIS tools should be algorithms.