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+_This is a work in progress. Do **not** start implementing anything without discussing with @knolleary first_
+
+There are some requirements around allowing dynamic contributions to the UI.
+
+Nodes can already contribute a custom panel to the sidebar. That is a stable API - albeit one that needs documenting.
+
+We do not have an api available to contributing elements to the menus or buttons in the header. This design note looks at what is required and how it should be done.
+
+<img width="400px" src="images/ui-customisation/ui-elements.png" />
+
+Ideally, whatever apis are provided for content in the header, the existing UI elements should be updated to use them.
+
+