Modifying JupyterLab static JS


Sorry in advance if this is a stupid question!

I’ve been attempting to modify the JupyterLab JS to remove the “Overwrite file” dialog prompt.

To do this I modified the code in packages/docregistry/context.js - however, when I deploy this to our server and build it via pip install ., the old JS is still being served up.

Is this the right way to modify the JS, and if so what am I missing in the build process?


You need to run jupyter lab with the --dev-mode flag to see your changes. See the developer instructions at

Ah… is there no way to build it in a way I can see my changes without dev-mode?