How do I make my custom kernel the default when starting a Jupyter interactive environment? I have written a native Jupyter kernel for Groovy, that is, a Jupyter kernel written in Groovy that listens to, and responds on, the appropriate ZMQ sockets. I have also extended the bgruening/docker-jupyter-notebook docker image to add my kernel and modified the jupyter.ini file to use my Docker image. This all works. I can launch a Jupyter Notebook (or use 'jupyter console --kernel groovy' from the command line) and interact with Galaxy. I can launch an interactive Jupyter environment in Galaxy and select 'Kernels -> Change kernel -> Groovy' and all of the above works fine; I just want my kernel to be the default. ------------------------------ Research Associate Department of Computer Science Vassar College Poughkeepsie, NY