Features

Simulation you can measure

Exact swept-capsule cutting on a heightmap: every move is applied in one pass, so cost follows the swept area, not the stamping density.
Precise cut edges: the simulator records where the cutter edge passed next to every step and the renderer slides wall vertices onto it. Curves stay round at any resolution (switchable per file).
Measurements: bounding dimensions of every remaining piece, surface heights, removed and remaining volume, rapid-collision and bed-collision warnings by move number.
Instant rewind: per-move undo patches and keyframes make scrubbing a 200k-move program cheap; long seeks stream across frames so the UI never freezes.
Work origin offset and Z zero: place a part anywhere on a larger blank; Z0 at the stock top or the bed.

A pseudo file system with nested folders; open/save dialogs manage folders in place.
Several files open at once in tabs; the set of open files is remembered.
50 MB of storage per account (file bodies plus saved simulation states). Files are yours: export or delete any time.
Loading is cached at three levels — the edge (Workers KV), the server (parsed summaries by content hash) and your browser (IndexedDB with ETag revalidation).

Filled shapes (rectangles, ellipses, polygons, paths) composed as objects and sub-objects that double as layers: visibility, lock, nesting, ordering.
Import SVG files; export SVG.
Assign a machining operation per shape or per layer: pocket, profile outside/inside, engrave — with depth, step-down, feed, plunge and step-over.
Generate the G-code and preview it in the renderer immediately; regenerate after edits.

A parametric feature timeline: sketches on XY planes at any height, extrusions that join or cut.
Architected so the kernel can grow (fillets, revolves, other planes) without changing documents.
Waterline roughing turns the part into a program: each distinct height is pocketed from the top down, and the result is previewed in the renderer.

An OAuth-protected MCP server: connect Claude web as a custom connector and it can list, read, create and edit your files, analyse programs, generate G-code from drawings and models, browse and publish designs.
Live view: while you have a file open, the assistant can see your camera, the region you highlighted and the playhead, and can draw labelled boxes in your 3D view or move the playhead to show you something.
Full documentation is served to the model through the get_help tool and at /docs/mcp.