CAD as Code

Parametric mechanical CAD expressed as version-controllable source code (Python, OpenSCAD DSL, or similar) rather than a GUI feature tree. Tools like CadQuery and Build123d wrap the Open CASCADE B-rep kernel to generate STEP files directly from scripts and AI text-to-CAD models. The approach enables Git revision tracking and automated simulation pipelines across aerospace and hardware engineering.

Key technical architectures and manufacturing innovations include:

• PADL-2 (Part and Assembly Description Language 2): Pioneering Constructive Solid Geometry (CSG) solid modeling system and textual part description language developed by the Production Automation Project at the University of Rochester; foundational historical trunk for CAD-as-code and solid geometry kernels.
• GeoField Generative Bracket Model: Generative mechanical engineering design tool utilizing continuous SE(3)-equivariant geometric fields and immersed FEA solver verification to synthesize load-bearing structural brackets from boundary and load specifications.
• CADAM: Adam's open-source browser text-to-CAD app. Generates parametric OpenSCAD from natural language and images, extracts slider parameters, renders via OpenSCAD WebAssembly and Three.js, exports STL/SCAD/DXF. Distinct from Lockheed/Dassault historic CADAM.
• OpenSCAD: Script-only solid 3D CAD modeller. Reads a description language and compiles CSG plus 2D extrusions; no interactive feature tree. Uses CGAL for CSG evaluation. Common LLM target for text-to-CAD (CADAM compiles OpenSCAD to WebAssembly).
• B-rep geometry kernel: Boundary-representation solid modeling kernels that keep geometrically and topologically consistent 3D solids (faces, edges, vertices, NURBS). Commercial kernels include Parasolid and ACIS; Open CASCADE Technology is the open-source kernel under CadQuery and FreeCAD. Boolean, fillet, and offset operations are indispensable for manufacturing CAD and notoriously brittle.

Leading industrial manufacturers, hyperscalers, and engineering operators include:

• Shapr3D: Csanády first CAD-as-code startup (2010) — He founded his first CAD startup in 2010 after a brief stint as an iPhone developer. While this first venture was unsuccessful, Csanády kept thinking.
• Neumann: Csanády CAD-as-code thread (Aug 21, 2026) — CAD-as-code has been a long-standing promise of our industry, but it has never really become a mainstream method for 3D modeling. This comes down to a few different reasons, and it feels like with the rise of LLMs (which excel at coding), that might change.
• Adam: CADAM open-sourced (Show HN) (Sep 5, 2025) — Hey HN! I'm Zach from Adam ( We’re building an AI co-pilot for mechanical CAD software.

Major industrial breakthroughs and commercial milestones include:

• University of Rochester Production Automation Project releases PADL-2 on VAX (Jun 1, 1981): PADL-2 is the historical successor to CAD-as-code. CAD-as-code on a VAX. We forgot and reinvented the same thing.
• Csanády first CAD-as-code startup (2010): He founded his first CAD startup in 2010 after a brief stint as an iPhone developer. While this first venture was unsuccessful, Csanády kept thinking.
• CADAM open-sourced (Show HN) (Sep 5, 2025): Hey HN! I'm Zach from Adam ( We’re building an AI co-pilot for mechanical CAD software.
• Connor Kapoor releases GeoField Equivariant Generative Bracket Model (Aug 20, 2026): An SE(3)-equivariant field model and immersed FEA for generative bracket design. Give it a box and a load, and it designs a solver-certified bracket, functioning as a live 3D designer.
• Csanády CAD-as-code thread (Aug 21, 2026): CAD-as-code has been a long-standing promise of our industry, but it has never really become a mainstream method for 3D modeling. This comes down to a few different reasons, and it feels like with the rise of LLMs (which excel at coding), that might change.