FluidCAD
Parametric 3D CAD design using JavaScript code with live viewport
FluidCAD is a web-based parametric CAD application that models geometry through JavaScript code instead of mouse-driven GUI operations. Users write code to define extrusions, fillets, boolean operations, and patterns; dragging in the live viewport generates code values that get locked into the script. It supports STEP file import/export with color, a feature history that can be stepped through and rolled back, and VS Code extension support. Gained 149 upvotes on Show HN today, targeting engineers who want code-first CAD with a traditional feature tree.
Panel Reviews
The Builder
Developer Perspective
“FluidCAD solves the thing OpenSCAD got wrong: the 'drag to prototype, lock to code' loop makes it accessible without sacrificing programmability. STEP export means it fits into actual hardware workflows, not just rendering. For software engineers doing mechanical work, this is the missing middle ground between Fusion 360's complexity and OpenSCAD's austerity.”
The Skeptic
Reality Check
“Code-first CAD has a 30-year history of failing to reach mainstream adoption because engineers and designers don't want to write JavaScript. FluidCAD will appeal to a very narrow slice of software developers who also do mechanical work. The STEP import/export is table stakes, not a differentiator, and Onshape's API does everything this does for teams who need collaboration.”
The Futurist
Big Picture
“When AI can generate CAD from natural language, the tools that survive will be the ones with programmatic, diffable representations — not binary blob formats. FluidCAD's JavaScript-first approach puts it in exactly the right position for the AI-assisted hardware design wave that's coming. This is the OpenSCAD for the LLM era.”
The Creator
Content & Design
“I appreciate the concept but the UI is clearly built by engineers for engineers. There's no real onboarding, the documentation assumes CAD literacy, and the JavaScript API surface is intimidating for anyone coming from traditional design tools. Until there's a visual-first entry point, this stays a curiosity for most designers.”
Community Sentiment
“this is what OpenSCAD should have been”
“finally a CAD tool that doesn't fight version control”
“code-first CAD is the only sane workflow”