# Partwright

> AI-driven parametric CAD in the browser. Modeling engines: JavaScript (manifold-3d mesh API, incl. `api.sdf` signed-distance fields and `api.params`), OpenSCAD (.scad), BREP (replicad/OpenCASCADE solids with selective fillets/chamfers and STEP export), and voxel. All interaction is via the `window.partwright` console API. `window.mainifold` is a legacy alias.

## Entrypoint

Navigate to `/editor` -- you drive the tool programmatically via `window.partwright`, and see your geometry by calling the render tools (below), so there is no tab to click.

## Quickstart

```js
partwright.help()                        // List all available methods
await partwright.createSession("name")   // Start a named session (uses active language)
await partwright.runAndSave(code, "v1 - description", {
  isManifold: true, maxComponents: 1    // Validate before saving
})
// JS code must end with: return <Manifold object>;
// SCAD code uses standard OpenSCAD syntax (no return)
```

`await` every async method. Without `await` you'll inspect a Promise object instead of the actual result.

## Verify visually after structural changes

Stats alone miss warped roofs, twisted spires, and wrong proportions:

```js
partwright.renderView({ elevation: 0,  azimuth: 0,  ortho: true })  // front
partwright.renderView({ elevation: 0,  azimuth: 90, ortho: true })  // right
partwright.renderView({ elevation: 90,              ortho: true })  // top
```

Or call `await partwright.renderViews({ views: "box" })` for a single composite of all six faces (front, back, left, right, top, bottom) -- the all-faces check.

## Resuming a session

```js
await partwright.openSession(id)
const ctx = await partwright.getSessionContext()
// ctx.notes -- [REQUIREMENT]/[DECISION]/[FEEDBACK] context from prior work
// ctx.versions -- prior versions with geometry summary
// ctx.agentHints.recentErrors -- last 5 validation errors (avoid repeating them)
```

## Tagging faces with color

For a flat axis-aligned face, derive the seed from the bounding box:

```js
const bb = partwright.getBoundingBox();
await partwright.paintRegion({
  point:  [(bb.min[0]+bb.max[0])/2, (bb.min[1]+bb.max[1])/2, bb.max[2]],
  normal: [0, 0, 1],          // outward-pointing normal of the top face
  color:  [1, 0, 0],          // RGB 0..1
  name:   "Top",
})
// Save an uncolored baseline first -- re-running new geometry invalidates the painted triangle indices (call clearColors() before changing the model).
// Check {error} on the return and confirm with listRegions().
```

For organic shapes, code-authored features, or anything where flood-fill is unreliable, prefer `paintByLabels` (when you author the model with `api.label(...)`), `paintNear` / `paintInBox` (coordinate-driven), or `paintPreview` to dry-run a selector. See `/ai.md#color-regions`.

## Language switching

```js
partwright.getActiveLanguage()            // -> 'manifold-js' or 'scad'
await partwright.setActiveLanguage('scad') // Switch to OpenSCAD
```

## Docs

- [Full API reference and workflow guide](/ai.md)
- [What's new — recently shipped features](/whats-new)
- `partwright.help()` in the browser console for live method discovery