This is an instance of the LOFAR pipeline template into the LOFAR rest API (https://github.com/EOSC-LOFAR/lofar_workflow_api).
The run_pipeline() function is modified to allow the inclusion of a third parameter to pass a calibrator observation along with the target becoming run_pipeline(observation1, observation2, **kargs).
It use both IEE and xenon-flow to start the computations on a given cluster using xenon and CWL.
The step-by-step guide to add a pipeline to the LOFAR rest API is given here.