Error While Adding Tool

I am working on “Segmentation” page

I was trying to add PlanarFreeHandContourSegmentationTool.
However, after adding it, when I use that tool I get “A contour segmentation must be active” error

This doesn’t happen if I add other features like “PlanarFreeHandROI” or “LivewireContour”

We currently don’t support contour creation. You’ll need to create a contour-type segmentation first, then add it using the tool.

Hi @ecarmu, I’m trying to add similar tool to OHIF but I don’t know where to start. Would you mind sharing some tips how to add such a tool?