Source-Available Engineering Simulation & Optimization Platform
Visual Modeling · Parametric CAD · Topology & Lattice Optimization · FEA · Solution Spaces · Sensitivity Analysis · Surrogate AI · Multi-Objective Optimization
PyLCSS (Python Low-Code System Solutions) is an integrated product development environment for engineering design, enabling engineers to model and analyze multidisciplinary systems through an intuitive node-based visual interface, all within a single desktop application.
The core concept is the Solution Space approach for robust design: instead of seeking a single optimal point, it identifies box-shaped regions of valid designs that allow decoupled subsystem development, as introduced by:
Markus Zimmermann, Johannes Edler von Hoessle, "Computing solution spaces for robust design", Int. J. Numer. Meth. Engng., 2013. DOI: 10.1002/nme.4450
- Parametric CAD — CadQuery and linked FreeCAD parts
- FEA — CalculiX static analysis for single- and multi-body models
- Topology Optimization — structural and thermal SIMP workflows with CAD/STL output
- Lattice Optimization — variable-density gyroid, Schwarz primitive, BCC, octet, and honeycomb cells with STEP/STL/3MF output
- Impact — OpenRadioss setup, execution, playback, and checks
- Solution Spaces — feasible-region and product-family exploration
- Multi-Objective Optimization — local, global, evolutionary, and multi-start solvers
- Sensitivity Analysis — Sobol, Morris, FAST, and Delta
- Surrogate Models — MLP, random forest, gradient boosting, and Gaussian process
- System Modelling — graph-based functional architecture
- AI Assistant — multi-provider, tool-driven project editing
- Black-Box Integration — wrap external tools in an
evaluate(x)function
Detailed documentation on node types, workflows, and solver configuration is available in the Help widget inside the application.
Run PyLCSS-2.2.0-Setup-x64.exe. Setup displays the PyLCSS license and a
separate third-party notice, then installs an isolated Python runtime, the
declared Python packages, and Start Menu/desktop shortcuts. CalculiX,
OpenRadioss, and FreeCAD are downloaded only when their optional tasks are
selected. Normal startup is the terminal-free PyLCSS.exe at the application
root. Installed copies check the official GitHub Releases feed at most once a
day. When a newer stable version is available, the launcher offers to download
the matching Windows setup and SHA-256 file, requires a trusted Authenticode
signature, and hands the upgrade to Setup. Setup replaces release-managed
application files and installs any new or changed locked dependencies. The
check can be suppressed with PyLCSS.exe --skip-update-check or the
PYLCSS_DISABLE_UPDATE_CHECK=1 environment variable; use
PyLCSS.exe --check-for-updates to force a check. Developer checkouts never
auto-update. Normal application startup never runs pip or modifies the system
PATH.
The reproducible setup recipe and signing-ready installer source are under
installer/windows/. Windows CPython 3.12 package artifacts are pinned by
version and SHA-256 in requirements-windows-py312.lock.
For an update to be discoverable, publish a stable GitHub Release tagged
vX.Y.Z (or X.Y.Z) and attach both
PyLCSS-X.Y.Z-Setup-x64.exe and its generated .exe.sha256 file. Public
release artifacts must be built with build_windows_installer.ps1 -RequireSignature and a trusted code-signing certificate; unsigned online
updates are rejected.
Requirements: Python 3.10+ · Windows 10/11 (macOS/Linux: experimental)
git clone <repository-url>
cd pylcss
python -m venv .venv
.venv\Scripts\activate # Windows
# source .venv/bin/activate # Linux/Mac
pip install -r requirements.txt
# Optional: download CalculiX, OpenRadioss, FreeCAD (interactive)
python scripts/install_solvers.py
python -m pylcss.mainExternal solvers (CalculiX, OpenRadioss, FreeCAD) are optional. PyLCSS opens cleanly without them; solver nodes remain available for deck-only preparation and show their detected runtime status in the component-library tooltip. Attempting a full solve without the required executable reports a node error. The external tools are governed by their own upstream licenses (CalculiX: GPL, OpenRadioss: AGPL-3.0, FreeCAD: LGPL-2.1+).
Licensed under the PolyForm Shield License 1.0.0.
Examples of permitted noncompeting uses include personal projects, academic
research, and internal business work. Providing a product or service that
competes with PyLCSS is not permitted, even if that competing offering is free.
The complete terms and definitions in LICENSE control; these examples are not
an independent license grant.
See LICENSE for the complete standardized PyLCSS terms and NOTICE for separately licensed dependencies and optional components. See PRIVACY.md for AI data handling and SECURITY.md before opening projects or serialized models from other people.