Try it

Round every edge. Then turn it over.

A wall bracket made in Kloss, with two screw holes and a slot. Drag it round to look at it from any side, and move the slider to change the fillet on every edge at once.

Fillet, every edge
Rnone
What Kloss measures
Size64 × 36 × 44 mm
Volume–
Weight in PLA–
Triangles–

Each step is Kloss's own STL export of this bracket. At 3 mm the kernel refused (the walls are 6 mm thick) and changed nothing, so the slider stops at 2.5.

The window

Everything on one screen.

Models in tabs. Shapes on the left, Properties on the right, and a workplane measured in millimetres in the middle.

Kloss's window: tabs, the Shapes panel, the toolbar, a phone stand selected on the workplane with its sizes, and its Properties. 1 2 3 4 5 6
  1. Tabs. Every model in its own tab, next to the Dashboard (⌘1).
  2. Shapes. 17 basic shapes and 22 code starters. Click to add one, or drop it onto another shape's face.
  3. Tools. Group, align and mirror, fillet and chamfer, sketch, workplane, ruler and measure.
  4. The workplane. Handles resize, lift and turn. Click a size and type 80, 2cm or 30+5.
  5. Properties. Size, colour, solid or hole, the shape's own settings, its fillets, and its weight in your material.
  6. Print, export and AI. Send the model to your slicer, export STL, OBJ or 3MF, or open the AI on either side.

In the beta

Every feature, on screen.

All of this is in the free beta. It runs on your Mac and saves to local files.

A blue phone stand selected on the workplane, with its handles and dimension lines reading 80.00, 70.00 and 83.28.

Shapes on a millimetre workplane

Box, cylinder, polygon, star, slot, teardrop, gem and ten more. Pull a handle, turn an arrow, or click a size and type it. Sizes snap to the grid you pick.

A red bracket in edge mode: three edges along the top of its wall picked in orange, and the radius box reading 3.

Fillet and chamfer any edge

Press ⇧F, click the edges, type a radius and see it before you press Return. An exact B-rep kernel builds it, even after holes and groups.

An SD card holder with eight slots, and the Parts list: one box and eight holes in a group.

Holes and groups

Make any shape a hole (H) and group it (G): the group is the solids minus the holes. Bundle and intersect too, and every boolean comes out watertight.

The Code tab of the Shapes panel: rounded box, enclosure with lid, egg, spur gear, gear rack, bolt, nut, threaded hole and hinge, beside a gear on the workplane.

22 parametric starters

Gears and racks, bolts, nuts, threaded holes, a print-in-place hinge, springs, snap-fit clips and enclosures. Pull a starter's handles and its settings follow.

The spur gear's JavaScript in the code panel, with line numbers and its log line, beside the gear.

Ask for a part, the AI writes it

Describe what you need and the AI writes it as a code shape: a part with its own settings, like teeth, size or wall thickness, that you change in Properties. Into code? Open the script and edit it yourself. It runs as you type. OpenSCAD files open the same way.

Sketch mode: the word Kloss over a rounded tag with a ring hole, and the sketch tools in the toolbar.

Sketch, extrude, revolve

Press K and draw lines, arcs, curves, rectangles and circles on the workplane or any face, then extrude or revolve. SVG logos come in as sketches.

A green key tag with a ring hole and raised white letters reading Kloss.

Text in any Mac font

Type a name and pick a font you have. It becomes a solid you can raise, engrave or cut through: key tags, labels and lids.

The AI sidebar beside an SD card holder: the request, the steps it took, its answer with sizes and weight, and a second request in progress.

AI beside your model

Claude Code or ChatGPT (Codex) in the sidebar (A), on your own subscription. Describe a part or attach a photo or PDF; it lists each step, and you can undo any of them.

The Export menu: STL whole model, OBJ, 3MF with colours, Open in Bambu Studio, Open in OrcaSlicer, Kloss file.

Export, or print in one step

STL, OBJ, or 3MF with your colours. Print… (⌘P) opens the model in Bambu Studio or OrcaSlicer, ready to slice.

The Dashboard's Recents: a twisted vase, a gear pair, a wall bracket, a key tag, workshop parts and a desk set, with folders Desk, Workshop and Gifts.

A home for your models

Tabs, folders, favourites and search. Add a synced folder in Dropbox or iCloud Drive and its models open and save in place.

The same workplane of parts, the left half in light mode and the right half in dark mode.

Light and dark, like your Mac

Kloss follows your Mac's appearance as it changes. Models keep their colours, and sizes and handles stay readable in both.

The Keyboard shortcuts sheet: view, shape properties and helpers.

Simple keys

Single letters for shapes and tools, one modifier for the rest, and the Mac's own keys where they exist. ⇧H lists them all and ⌘K finds any command.

Bring your work

Bring your work with you.

Parts from your CAD app, a download site or OpenSCAD open in Kloss, and finished models go straight to your slicer.

In

  • STEP .step .stp from Shapr3D, Fusion, Onshape, SolidWorks or FreeCAD, with names, colours and assemblies. They come in as meshes, so Kloss's fillets don't reach them.
  • Meshes .stl .obj .3mf, checked as closed solids. Resize them, cut holes in them and group them like any shape.
  • OpenSCAD .scad, read by Kloss's own interpreter. Customizer variables become settings; MCAD and BOSL2 work.
  • SVG .svg logos and outlines, as sketches ready to extrude.

Out

  • STL .stl: one closed solid in millimetres, holes cut.
  • 3MF .3mf with each part's name and colour, and OBJ .obj with one object per shape.
  • Print… ⌘P opens the model in Bambu Studio or OrcaSlicer.
  • Kloss .kloss: one file, yours, on your Mac.

Choose File › Import… (⇧⌘O) or drop files onto the Dashboard or the model. Kloss says what it couldn't bring over, so keep your originals.

For your agents

Your agents can model here too.

While Kloss is open, it runs a small MCP server on your Mac. Any agent you point at it can add shapes, fillet edges, write code shapes, measure, export, and check its own work with a screenshot.

It works in a background tab and never takes over the model you're on. Copy Reference (⇧⌘C) hands it a model, or just the parts you've selected.

# the address and token: Kloss › Dashboard › MCP live
url   http://127.0.0.1:43160/mcp
auth  Bearer <your token>

# some of what an agent can do
get_document       apply {commands}
add_shape          group {union|bundle}
fillet_edges       chamfer_edges
create_code_shape  create_sketch
get_stats          screenshot {ids}
export_model {stl|obj|3mf}
A real Mac app
Native Swift and the system's WebKit, with an exact B-rep kernel built in. macOS 12 or later on Apple silicon.
Your files
Models stay on your Mac as plain files. No account and no cloud. It works offline.
Your AI
Claude Code or ChatGPT on the subscription you already have, or none at all.
Free in beta
No key needed while Kloss is in beta. From release: €79 once, a licence for life.