Interface tour

This page describes the working build, not a mock-up: every screen region and every gesture here exists in the application today. Getting started covers the download and your first part.

One window

CoCAD is a single window with the layout CAD hands expect. An app bar runs along the top (file, undo/redo, the Ctrl+K hint), with the tool ribbon under it. The browser tree sits on the left, the viewport takes the centre, and an inspector on the right shows the properties of whatever is selected. Both side panels collapse. Along the bottom: a timeline strip that lists what you have made, and a status bar with the document’s display units.

Ribbon tabs and groups appear only when the connected build actually registers their tools — a build without the sketch solver is honestly one tab short rather than one broken button richer. Nothing in the ribbon is UI-only: every button sends the same command an AI would send over MCP.

The viewport

Navigation will feel familiar if you’ve used other CAD tools. Middle-drag pans (the grabbed point stays under the cursor), Shift+middle-drag orbits, and the scroll wheel zooms to the cursor. Two deliberate additions: a left-drag that starts on empty space orbits, so turning the model needs no modifier at all, and the right button splits by distance — drag and it pans, release within a few pixels and the context menu opens. Never a time threshold; the same motion always means the same thing.

F fits the model, keys 1–8 jump to the standard views, and Esc is always safe and never destructive. No middle button? The docked navigation bar arms Orbit or Pan as a mode, steps the zoom, fits, and toggles the projection — every gesture has a clickable spelling.

Hovering pre-highlights what a click would take, a click selects, and Ctrl toggles. The selection is shared session state: your AI sees exactly what you have selected, and you see what it selects.

Sketching

Starting a sketch arms a picker: planar faces, the three origin planes, and any construction plane light up under the cursor, and one click picks the support — the camera swings to look straight at it and the grid fades in. There is no fallback dialog; the pick is the route.

Drawing is single-key: line L, rectangle R, circle C, arc A, spline S (and P for the control-point kind), dimension D, trim T, offset O, text X, mirror M, pattern E. A mode picker on the sketch HUD switches each tool’s construction — three-point rectangle, centre rectangle, tangent arc — so nothing about a shape’s recipe is reachable by an AI and not by a person. Snapping (endpoints, midpoints, centres, the grid and more) can be toggled per kind in the preferences.

Sketches are edited, not just drawn: trim, extend, break, fillet, chamfer, move, mirror, offset and pattern all exist as gestures with live previews, and dimensions are edited in place — click the value, type the new one.

Solid tools

Extrude, revolve, fillet, chamfer, shell, mirror and combine are in today. The sweeping tools draw a translucent ghost of the result while you aim, and their numbers are edited on the geometry itself — the distance label on an extrude and the angle labels on a revolve are input fields hanging on the model, not rows in a distant panel. Extrudes reach distances, “to object”, “through all” and “to next”, and every boolean role (new body, join, cut, intersect) is a mode on the same tools.

The browser tree

The tree lists the document: an Origin folder first, then bodies, sketches and construction planes. Every row has a visibility eye; a folder’s eye has three states (all, some, none visible) and restores the per-child state you had rather than blanket-showing everything. A reference that breaks — a sketch on a face that a later edit consumed — gets a warning badge and a right-click repair that re-points it without losing what stands on it.

History

Undo is Ctrl+Z, redo is there beside it, and the history panel shows every step — yours and your AI’s, each attributed to whoever made it. You can jump the document to any step on the timeline, including all the way back to empty, and walk forward again. Undoing a step that is not yours asks first instead of silently discarding a collaborator’s work.

Keyboard first

Ctrl+K opens the command palette; ? opens the shortcut overlay. Both are generated from the same shortcut catalogue the tools themselves read, so a new tool appears in both the moment it ships — there is no second list to fall out of date.

Working alongside an AI

When an agent is connected over MCP, its work is visible: an activity indicator shows a command in flight, history steps carry the author’s name, and its selection and camera requests go through the same bus yours do. You can pause an AI’s edits and resume them; its queued work waits rather than fighting you for the model. The rule underneath the whole application: if an AI can do it, a person can, and the other way round.

Settings

The preferences window renders whatever the connected build declares — snap toggles, camera animation speed, dimension precision and more — so options never drift from the core that honours them. Display units live on the status bar per document; storage is always millimetres underneath, so changing units never touches geometry.