Sketch JSON (host notes) · novolis-apps

Authoritative contract

Full wire format (versions, fields, examples, legacy v1):

[`novolis-governance/docs/sketchjson.md`](../../../novolis-governance/docs/sketchjson.md)

Implementation: Novolis.Avalonia.Controls.Sketch → SketchJson.Serialize / Deserialize.

This page only covers how Sketch Studio uses the format.

Host responsibilities

Concern	Host behavior
File filter	`*.sketchjson` on Open / Save As
Extension	Appends `.sketchjson` if the user omits it
Grid sync	Copies `SketchControl` grid props onto `doc.Grid` before serialize
Dirty / MRU	Outside the file — [Documents](./documents.html)
PNG / SVG	Outside the file — [Export](./export.html)

Features that need version 2+

Speech bubble / text / text box / image / rotation / fuse groups require v2 fields (kind, rotationDegrees, groupId, text, fontSize, imagePngBase64).

Layers (version 3)

When extra layers exist (or elements leave the default layer), documents write version: 3 with:

layers[] — id, name, optional visible / locked
activeLayerId
element layerId (omitted when default)

Hidden layers are skipped in the canvas and in PNG/SVG export. Locked layers reject paint-bucket / erase / transform.

Colors

strokeColor / fillColor accept #RRGGBB or #AARRGGBB (alpha). Fully transparent: #00000000.

Round-trip checks

Unit: Novolis.Avalonia.Unit / SketchDocumentTests
Host: --smoke exercises serialize → deserialize of fused + text + layers + fill — Smoke and release

Not CAD

Do not confuse with `.cadjson` (Draft Studio). Sketch is freehand / whiteboard; Draft is analytic CAD-light.