A native macOS CAD/CAM studio for leathercraft, pattern making, and sewing.
Pathstitch is for makers who want CAD precision without CAD overhead. Sketch a pattern with snapping and
live dimensions, round corners parametrically, drop in saddle‑stitch holes and glue tabs, then export
cut‑ready DXF/SVG/PDF — or import a 3D .step model and unfold it into flat panels you can actually cut
and sew. It's a fast, native SwiftUI app backed by a real geometry kernel (ezdxf, shapely, OpenCASCADE),
not a web wrapper.
⬇ Download the latest release — grab
Pathstitch-x.y.z.dmg, drag it into Applications, and you're running.
- Requires: an Apple‑Silicon Mac (M1 or newer) on macOS 14 (Sonoma)+.
- This app is not Apple Notarized: The app is ad‑hoc signed, not Apple‑notarized (notarization needs a paid $99/yr Apple Developer ID, which this project doesn't have yet), so the very first launch needs a one‑time Gatekeeper approval — a 15‑second, two‑click bypass. See Installing. After that first approval it opens normally forever.
Is it safe? Yes, completely. The app is 100% open-source, so the entire source code is public and auditable. The only reason it isn’t officially 'notarized' is because Apple charges a $99/year fee to maintain a developer account, which this free project doesn't have yet.
Line, circle, rectangle, polygon, text, and an Illustrator‑style pen tool, all with point/edge/grid snapping and
on‑creation dimensions — type a width, Tab, type a height, Enter, done. No hunting through panels.
1.-.Shapes.snapping.mp4
- Parametric fillet & chamfer (G1/G2). Every corner is independent, draggable to size, and stays editable forever — it can even grow until adjacent fillets meet. Works on polylines, the corner where two separate lines meet, and imported geometry.
- Trim, Fusion‑style: hover a segment to see exactly what will be removed, then click — or drag across several — to cut at every intersection.
- Boolean union / subtract / intersect on closed shapes, and Explode to break a compound back into its individual edges.
- Move/rotate gizmo, point‑to‑point move, scale, mirror, reflect, duplicate.
2.-.Fillet.mp4
- Stitch holes & saddle‑stitch patterns generated along any path, with spacing and corner controls.
- Offset, convert‑lines (dashed/perforated styles), fill / hatch a closed region, patterning (grid, circular, or along a path), and paper folding (crease lines + glue tabs) for assembling 3D objects from flat stock.
Video.3.-.Sewing.Holes.mp4
Import .step / .stp, inspect it in a Three.js viewport, and unfold developable surfaces into flat
nets ready for the 2D tools — the thing most pattern tools simply can't do. Drag in several models at once
and they auto‑arrange; take a cross‑section from any plane to sketch against.
Video.4.-.3D.mp4
DXF, SVG, PDF, and PNG export; native .stch project files; and Finder QuickLook previews + thumbnails
for DXF and STEP — press Space on a file and see the real geometry, not a generic icon. Plus the niceties:
customizable keybinds, light/dark themes, a ⌘K command palette, and a rearrangeable toolbar.
Video.5.-.Export.mp4
Draw
- Line / Circle / Rectangle — core primitives with live dimensions.
- Polygon — N-sided shapes, drag to set radius/rotation, tab for sides.
- Text v3 — double-click to edit inline, choose system fonts, adjust size, spacing, bold, italic, underline, and multi-line.
- Pen — Illustrator-style bézier paths.
- Snapping — point/edge/grid snapping while drawing.
- Reference images — import, calibrate, transform, and trace/vectorize image underlays.
Edit
- Fillet / Chamfer — parametric, per-corner, G1/G2, draggable; shared radius for corners picked together.
- Trim — hover-to-preview, click or drag to cut at intersections.
- Offset — chain-select, live ghost, flip side, construction lines.
- Join / Cleanup — bridge hanging endpoints with straight lines.
- Convert Lines — restyle to dashed / perforated / decorative lines.
- Boolean — union, subtract, and intersect closed shapes.
- Fill / Hatch — fill a closed region with a solid or hatch pattern.
- Explode — break a compound / polyline back into its individual edges.
- Move — gizmo + exact point-to-point.
- Scale — live drag, from center or a picked point.
- Mirror — objects/mirror-line modes with live ghost.
- Reflect / Flip / Duplicate — quick transforms.
- Layers v2 — organize geometry by layer; click a layer in the panel to select its geometry.
Measure & dimension
- Measure — ad-hoc distance lines.
- Dimension — linear / radius / point-to-point with a parameter engine (formulas, variables, units,
fx:/driven).
Make
- Stitch holes — saddle-stitch generation along any path, spacing/corner controls.
- Keep-out avoidance — gap the stitch line around tagged hardware.
- Patterning — rectangular, circular, and along-a-path arrays with live ghost preview.
- Paper folding — crease lines + glue tabs for 3D assembly.
3D → 2D
- STEP import — load
.step/.stpinto a 3D viewport. - 3D bodies — drag-and-drop to import multiple 3D models with auto-distribution and 3D translation gizmos; plane cross-section previews.
- Plane projection — sketch from a cutting plane with cross-section previews.
- Unfold & Unwrapping — flatten developable surfaces and doubly-curved faces (conformal LSCM).
- Home v2 — press Home to frame all geometry or return to the default startup view if the canvas is empty.
Export & integrate
- Export — DXF, SVG, PDF, PNG with filters for selected-only or measurements and clear indicator checkmarks.
- Projects — native
.stchfiles. - QuickLook Previews — Finder previews + thumbnails for DXF (full curve support) & STEP (native fast 3D renderer).
- Batch mode — operate over many files at once.
Workspace
- Command palette — search-optimized palette (
Sor⌘K) to find and run any tool. - Keybinds & themes — customizable shortcuts and appearance (light/dark).
- Toolbar — zoned, rearrangeable, resizable panels with collapsible options.
- Recent projects — welcome screen with reveal/remove.
Single-key, Fusion/Photoshop-style defaults (all rebindable in Preferences → Shortcuts, taking effect immediately. Secondary standard macOS shortcuts like ⌘K for search are also supported).
| Key | Tool | Key | Tool | Key | Action |
|---|---|---|---|---|---|
V |
Select | L |
Line | S / ⌘K |
Search |
M |
Move | C |
Circle | ⌘Z / ⌘⇧Z |
Undo / Redo |
H |
Pan | R |
Rectangle | ⌘D |
Duplicate |
O |
Offset | P |
Pen | ⌫ |
Delete |
T |
Trim | D |
Dimension | ⌘⇧H / ⌘⇧J |
Flip H / V |
F |
Fillet | I |
Measure | N |
Toggle snapping |
B |
Chamfer | E |
Convert Lines | A |
Toggle chain-select |
G |
Add Holes | J |
Join / Cleanup | ⇧G |
Toggle grid |
Tools without a default key (Scale, Polygon, Text, Mirror, Patterning, Paper Folding) are reachable from the toolbar or the search palette, and can be bound in Preferences.
Pathstitch is a thin, fast SwiftUI front‑end over a persistent Python geometry worker. The UI never blocks on geometry: every operation is a JSON request streamed to a long‑lived backend process and rendered back.
┌──────────────────────────────┐ JSON over stdin/stdout ┌────────────────────────────┐
│ SwiftUI front-end (macOS) │ ─────────────────────────────────▶ │ Python engine │
│ AppState · DxfCanvasView · │ PythonBridge ↔ pathstitch_core │ ezdxf · shapely · numpy │
│ ThreeDViewport (WKWebView) │ ◀───────────────────────────────── │ pythonOCC (STEP) · │
└──────────────────────────────┘ │ matplotlib (PDF/PNG) │
└────────────────────────────┘
- Front‑end — Swift / SwiftUI (
Pathstitch/Pathstitch).PythonBridge.swiftkeeps onepython -m pathstitch_core.workerprocess alive and streams framed JSON to it. - Engine —
pathstitch_core/:dxf_ops.py(2D),step_ops.py/surface_unfold.py/net_unfold.py(3D & unfolding), driven byworker.py. - 3D viewport —
viewport3d.html(Three.js) inside aWKWebView.
For a packaged build, a trimmed copy of the Python environment and the engine are bundled into
Pathstitch.app/Contents/Resources/, so the shipped app has no external dependencies.
You only need this if you want to develop Pathstitch; users just download the .dmg.
Requirements
| Component | Version | Notes |
|---|---|---|
| macOS | 14.0 (Sonoma)+ | Developed/tested on macOS 26. |
| Xcode | 16+ | Built with Xcode 26.5 / Swift 6.3. |
| Python | 3.11 | The geometry backend. |
Python packages (pathstitch_core/requirements.txt + 3D/raster extras):
ezdxf # DXF read/write + 2D geometry
shapely # offsets, booleans, polygon ops
numpy # math
svgwrite # SVG export
matplotlib # PDF / PNG raster export
pythonocc-core # STEP import + 3D (OpenCASCADE) — install via conda-forge, not pip
Steps
# 1. clone
git clone https://github.com/Mason363/pathstitch.git
cd pathstitch
# 2. backend env (conda recommended for pythonocc-core)
conda create -n pathstitch python=3.11
conda activate pathstitch
conda install -c conda-forge pythonocc-core
pip install -r pathstitch_core/requirements.txt matplotlib
# 3. sanity check the engine
PYTHONPATH=. python pathstitch_core/test_dxf_ops.py # → "ALL TESTS PASSED SUCCESSFULLY!"When run from Xcode, the app falls back to your local interpreter + repo. Set the two fallback paths
once near the top of
Pathstitch/Pathstitch/Bridge/PythonBridge.swift:
"/opt/homebrew/Caskroom/miniconda/base/envs/pathstitch/bin/python" // your env (echo $CONDA_PREFIX/bin/python)
"/absolute/path/to/this/repo" // this checkoutThen open Pathstitch/Pathstitch.xcodeproj and ⌘R (or xcodebuild ... -configuration Debug build).
One command produces a self‑contained, drag‑to‑install image:
bash scripts/package_app.sh
# → dist/Pathstitch-1.0.dmg (~400 MB, self-contained, ad-hoc signed)It builds the Release app, copies a trimmed Python env (≈2.8 GB → ≈1.1 GB — OpenCASCADE stays; dev‑only
LLVM/Qt/VTK/headers are dropped) plus pathstitch_core into the bundle, ad‑hoc signs it, and creates a
.dmg whose window has the app next to an Applications shortcut (drag one onto the other). Point it at a
different env with CONDA_ENV=/path/to/env bash scripts/package_app.sh.
Styled installer window. Drop a scripts/dmg/background.png (500 × 500) and the packager builds a
positioned drag‑to‑Applications window over your artwork; without it you get a plain (but still functional)
drag‑install DMG. Use scripts/dmg/background-template.svg as the guide — it marks exactly where the app
and Applications icons land so you can paint a matching background (e.g. a leather‑cut texture). See
scripts/dmg/README.md.
The bundled env is arm64, so the image targets Apple‑Silicon Macs. For a no‑warning install you'd need a paid Apple Developer ID signature + notarization (
xcrun notarytool); without it, users do the one‑time bypass below.
Because Pathstitch isn't Apple‑notarized, Gatekeeper warns on first launch. Do this once:
- Open the
.dmg, drag Pathstitch onto Applications, and double‑click it. - On the “…cannot be opened because Apple cannot check it…” dialog, click Done.
- Go to System Settings ▸ Privacy & Security, scroll down, and click Open Anyway next to the Pathstitch message. Confirm with Touch ID / your password.
(Terminal alternative, if you trust the source: xattr -dr com.apple.quarantine /Applications/Pathstitch.app.)
Checking your macOS version: ▸ About This Mac, or sw_vers -productVersion (needs 14.0+).
Pathstitch updates itself with Sparkle. On the second launch it asks whether to check for updates automatically; you can change that any time in Pathstitch ▸ About Pathstitch (the Check for Updates… button and the Automatically check for updates toggle), or via Pathstitch ▸ Check for Updates…. Your settings persist across updates.
Cutting a release (maintainer):
- Bump
MARKETING_VERSIONandCURRENT_PROJECT_VERSION(Sparkle compares the build number) in the Xcode target. bash scripts/package_app.sh→dist/Pathstitch-<version>.dmg.bash scripts/make_appcast.sh <version>→ signs the dmg (EdDSA key in your login Keychain) and writesdist/appcast.xml.gh release create v<version> dist/Pathstitch-<version>.dmg dist/appcast.xml --title "…" --notes "…".
The app's feed (SUFeedURL) points at releases/latest/download/appcast.xml, so uploading the appcast as a
release asset is all it takes for existing installs to see the update. The EdDSA public key lives in
Info.plist (SUPublicEDKey); keep the private key (in your Keychain) backed up — losing it means no
future signed updates.
pathstitch/
├── Pathstitch/ # Xcode project + Swift sources
│ ├── Pathstitch.xcodeproj
│ ├── Pathstitch/ # main app target (App/, Bridge/, Modes/, Welcome/)
│ ├── DxfPreviewer/ # QuickLook preview extension
│ └── PathstitchThumbnail/ # Finder thumbnail extension
├── pathstitch_core/ # Python geometry engine (worker.py, dxf_ops.py, *unfold*.py)
├── scripts/package_app.sh # build a self-contained .dmg
├── scripts/make_appcast.sh # sign the dmg + emit the Sparkle appcast.xml
└── README.md
Pathstitch is an actively developed 1.1. The 2D pipeline (draw → edit → stitch → export) is the mature core; 3D STEP import + unfolding works for developable surfaces and is expanding. Currently Apple‑Silicon only — an Intel/universal build is possible by repackaging the backend on an Intel Mac.
Found a bug, hit a rough edge, or have an idea? It genuinely helps.
- 🐛 Bugs → open an issue. Steps to reproduce + a screenshot or short screen recording make it far easier to fix — visual and interaction bugs especially.
- 💡 Feature requests → open an issue. Tell me what you're trying to do; the goal matters more than a specific implementation.
- 💬 Questions, ideas to talk through, or showing off what you made → Discussions.
Before filing, a quick search of existing issues avoids duplicates. That's it — no account hoops beyond a free GitHub login.
Built with ❤️ by Mason Chen.
If Pathstitch saves you time, you can buy me a coffee. ☕
Pathstitch is licensed under the GNU General Public License v3.0 — see LICENSE.
It uses Potrace (GPL) for raster-to-vector tracing, which is why Pathstitch as a whole is distributed under the GPLv3.
The Finder QuickLook preview/thumbnail for .step files tessellates the B-rep
into a triangle mesh using foxtrot
(MIT/Apache-2.0), wrapped as a small Rust static library in
native/step_mesh. A prebuilt lib/libstep_mesh.a is
checked in so the Xcode build needs no Rust toolchain. To rebuild it (e.g. after
bumping the foxtrot pin), install Rust and run
native/step_mesh/build.sh.