jupyterlab-cell-toolbar
Domain: JupyterLab GUI
🎯 Motivation
A customizable toolbar above each notebook cell in JupyterLab. Extensions add buttons via the cell toolbar registry.
📋 Concrete Example
Register a toolbar item with nbCell.createCellToolbarItem('mybtn', rank, widget) to add a button to every cell.
🔗 Analogy
The cell toolbar is a mini remote on each cell — extension buttons sit there for quick per-cell actions.