A demo app built with Elements.
Sticky notes, pen, shapes and arrows on shared boards, with named live cursors, real-time edits and per-person undo.
Demo: Sketchmoor
- Agent: Claude Code, Opus 5.5 Medium
- Time: 22 min
- Cost: $6.93 at API rates, September 2026
elements create sketchmoor -scaffold=elementscode/demo-sketchmoorSketchmoor needed boards that several people draw on at once, named cursors that follow each person's pointer, strokes that appear as they are drawn, undo for each person and accounts with shared links. Each of those is a part of Elements, so the agent spent its 22 minutes on the whiteboard itself.
-
Shapes that sync. Shapes are a LiveTable, one view per board. Notes, pen strokes, rectangles, arrows and text are rows, and the board adds and moves them straight through the view, so every open copy updates as each edit lands.
-
Cursors and strokes in flight. A channel carries what is seen but never stored: each person's named cursor, the stroke under their pen and a shape mid-drag. Each browser drops its own echo.
-
Undo for each person. Erasing marks a shape as deleted, so it can come back. Each person keeps their own undo and redo steps, applied through the same view.
-
Shared by link. Opening a board's link adds the signed-in user to its members, and every edit checks that membership.
-
Thumbnails from the data. The board list shows each board drawn as an SVG from its shapes, cached until the next edit.
-
Data and sessions from SQL. Migrations define the boards and seed three demo accounts sharing two boards, a sprint retro of sticky notes and an architecture sketch. Each person signs in with a session.
The project server runs alongside the agent and answers as soon as a file is saved: it type-checks the templates, TypeScript and SQL, applies migrations and reruns the tests, so every question came back right away and the agent kept building.
The app type-checks with zero errors and all 22 tests pass. Every page works on desktop and phone.
The seed creates two boards that all three accounts share: "Sprint 14 retro",
sticky notes in three columns, and "Checkout architecture", a sketch of
services, arrows and notes. Every account's password is sketchmoor, and the
sign-in page lists them. Open a board in two browsers signed in as different
people to see each other's cursors and edits live.
| Name | |
|---|---|
| Ada Lovelace | ada@sketchmoor.dev |
| Grace Hopper | grace@sketchmoor.dev |
| Alan Turing | alan@sketchmoor.dev |
Demo: Sketchmoor
MIT. See LICENSE.