Besides the bug I also found a solution with help from InterSystems. We took JSON bundle example for base and wrote code to create class that would generate API app on server that would, when invoked with param, produce required JSON bundle in FHIR format. It took some time to refine and format everything to standard, but I found this example most helpful for my solution: https://github.com/inferno-framework/service-base-url-test-kit/blob/101f...