Canvas Editing

The board canvas edits like a design tool: you drag to select, use shortcuts, copy/paste across boards, and import or export whole diagrams. For element meaning, start at Nodes & Edges. For board setup, see the Boards Guide.

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Pointer and hand modes

The canvas has two interaction modes, toggled at the top of the tool rail on the left or with the V and H keys:

Pointer is the default for editors, and the canvas remembers your choice. In either mode, a middle or right drag, or Space held while you drag, also pans.

Read-only boards, such as published boards and previews, open in hand mode and do not run editing shortcuts.

Moving around

• Scroll pans; pinch or ⌘ + scroll zooms.
• The zoom readout in the bottom-right corner shows the current zoom. Click it for the View menu: zoom presets, fit, zoom to selection, auto-arrange and the background pattern.
• Double-click empty canvas to fit the whole board in view.

On Windows and Linux, read ⌘ as Ctrl throughout.

Auto-arrange

To restore the automatic layout after dragging nodes, open the View menu (click the zoom readout) and choose Auto-arrange. It discards every hand-placed position on the current layer and lays the board out again; ⌘Z undoes it. The item is greyed out when you haven't moved anything by hand.

Selecting and arranging

Click selects one element; ⌘-click adds to the selection; a pointer-mode drag selects everything it touches. From there:

Nudging or dragging an element pins it, and automatic layout stops repositioning it. A held arrow key counts as one action, so one undo moves the selection back.

Renaming inline

Select a node and press Enter or F2, or double-click the name.

Copy, paste, and duplicate

A copied container brings its children, and copied connected nodes bring the edge between them.

Paste works across boards: copy on one board, open another, even in a different tab, and paste.

Two things change when you paste:

• A pasted copy is yours. When you copy an element that a source owns, you get a plain, hand-authored copy without the source's claim. The same goes for a nested layer: the copy does not take the original's child layer, which stays where it was.
• Governed boards stage the paste. On an app board, pasted elements arrive as staged additions, badged and reviewable like any other edit.

Copy a style, paste a style

To copy one element's style to others:

Style means appearance: fill, stroke, text color, font, corners, and effects. It excludes shape, icon, size, and position. Pasting a node's style onto an edge applies only the parts an edge can use.

Import and export

Import a diagram

Import diagram appears only while the board or layer you're on has no elements, and only if you can edit it.

1. On the empty board, click Import diagram beside Add element.
2. Click Choose file, or paste the text into the box. The dialog detects the format from the file extension or the text.
3. Check the preview: node and edge counts, the archetype each element will get, how each archetype was matched, and any adjustments.
4. Click Import. The elements appear on the canvas as one step, so ⌘Z removes them all.
5. Click Save to keep them. Until you save, the import is an unsaved change like any other edit.

Import reads:

If someone adds elements to the board while the dialog is open, Import refuses to run. Import never merges into existing elements.

How archetypes are matched

Each element takes an archetype from your catalogue by the first rule that fits. The kind in the file wins, then the exact name. After that come keywords in the name ("Orders DB" is a data store), then the drawn shape (a Mermaid cylinder is a data store). A Mermaid class that names an archetype, such as :::data_store, overrides the rest. Edges match on the verb in their label, such as "reads" or "calls".

An element that matches nothing imports without an archetype; change it on the canvas. A Mermaid line the importer can't read is skipped whole, never half-applied, and the preview lists it with every other adjustment.

Export a board

Click the download button at the top right of the canvas. Under Data:

Export covers the board or layer you're on, including unsaved edits, but not the layers beneath it. It leaves out links to source code. Exporting an unchanged board twice produces the same file, so exports diff cleanly in a repo.

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