A built-in add-on under Object › Plug-ins › Smart Pen:
- The Smart Pen Tool draws and edits Bézier paths without switching
tools: a click adds the next segment straight or curved (a panel
toggle; Tab flips the segment being placed or the last one), a drag
makes a smooth point (Alt breaks the handle, Shift snaps to 45°, Space
moves the point), a curve after a straight segment joins it tangent.
- On existing paths it selects and moves points, removes a point keeping
the shape (Alt-click), toggles smooth/corner (double-click), drags
handles, reshapes a segment by dragging it and inserts a point on it
(Alt-click); it closes, continues and joins open paths.
- The Smart Pen panel: next segment straight or curved, remove points
keeping shape, make smooth, make corner, retract handles, close or
join.
The tool stays out of both toolbars as shipped; the All Tools drawer
lists it under the add-on's heading. Commands are addon.pen.*; the
existing Pen tool, commands and menus are unchanged.
