An annotation is a small themed circle holding a fixed note glyph, a way to pin a piece of explanation to a spot on the canvas without adding a box of text that gets in the way. The note itself stays hidden until you want it: hover the marker to read it, click it to edit. It's perfect for footnotes, callouts, and reviewer comments that should be available but not in the foreground.
What it is
- A fixed-size circle (around 44 pixels) themed like a shape, with fill and stroke from the active theme and a single note glyph centred inside, tinted by the stroke colour.
- It's a marker, not a box: it doesn't resize and has no corner or rotate handles, so a canvas full of annotations stays tidy and uniform. The glyph is always the same note marker, not pickable per annotation.
- You can still move it, recolour it (via the Colours controls), bring it to front or send it to back, lock it, group it, link it, and delete it like any other element.
Adding one
Click Annotation. A new marker drops at the centre of the viewport, already selected, in one undoable step.
It inherits the active theme's colours, so it matches your diagram out of the box.
Reading and editing the note
- Hover to read. Pointing at an annotation that has note text floats a read-only preview of the note above every canvas element, so it's legible even when other shapes are painted on top of the marker. The preview vanishes when you move away. An annotation with no note yet shows nothing on hover.
- Click to edit. A plain click opens the editable note popover (the same one the note badge opens elsewhere). Type, then commit, and the change goes through history like any other edit. Clicking the same annotation again closes the popover. Dragging moves the marker instead of opening the editor, so a click that doesn't move opens it and a drag never does.
- Read-only viewers can hover to read and open the note read-only, but can't edit, move, or delete it, the same as every other element.
Exporting
In visual exports (PNG and SVG) an annotation renders as its themed circle; the note text isn't drawn, since it's a hover affordance rather than page content. Markdown export lists a labelled annotation under Elements with an (annotation) tag.
Use annotations for review notes and caveats you want available on demand without crowding the diagram. They keep a consistent size, so a dozen of them still look neat.
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