polykrom
Open-source parametric CAD in pure Rust for physical-world engineering, with stress analysis and an AI companion; a fork of SolidCraft.
What it does and how it connects
Polykrom is an open-source parametric 3D CAD application built in pure Rust. Sketch, constrain and build solids with a parametric feature timeline: change a dimension and the model rebuilds. Run it on the desktop, in the browser, or let AI agents model through the built-in MCP server. It is a fork of SolidCraft, aimed at engineering for the physical world: parts that can be analysed, assemblies that can be tested, and an AI companion that works through the same commands the user does.
Polykrom starts from SolidCraft and keeps its history, and fixes that help both go upstream as pull requests to SolidCraft first. Polykrom adds static stress analysis (stress, deflection, reactions and the safety factor against yield, solved by Nightfall's verified study runner in a separate program) and kernel robustness (trimmed faces whose boundary crosses itself mesh instead of crashing, and moved bodies keep their edges on STEP export). Coverage includes sketches and constraints, extrude, revolve, sweep, loft, fillet, chamfer, shell, draft, holes, threads, patterns, mirror, split and combine, parameters and configurations, assemblies with joints, motion studies, contact sets and interference, sheet metal with flat patterns, and STEP, IGES, 3MF, STL, OBJ and glTF in and out where supported, plus URDF export.
It is early but usable for simple parts: 75 of 76 public reference parts match their analytic or FreeCAD-computed volume, area, centre of mass and bounding box, and the other is a tracked bug. There are no Polykrom release builds yet; build it from source. Inside, the crates, binaries, design files and settings still carry SolidCraft's names, and polykrom and polykrom-cli are aliases.
Alternatives
Compare side by side- solidcore
A Rust port of NVIDIA's SMLib B-rep kernel, and the kernel family SolidCraft builds on, rather than a full parametric CAD application.
- datum
A from-scratch parallel-first deterministic B-rep kernel in Rust, rather than a full parametric CAD application.
- next.BREP.io
A unified mechanical and electronics CAD in Rust on its own B-rep kernel, with schematic, board and harness workbenches, rather than a mechanical-only CAD forked from SolidCraft.
- draftwork
Parametric CAD in the browser on OpenCascade compiled to WebAssembly, rather than a pure-Rust CAD with stress analysis and an MCP server.
Recurring errors it addresses
Error Index entries this tool is built to reduce or work around.
Sources
Not verified
- Pricing (none stated on the repo)
- Real user voices (the repo has no public issues)
- Latest release (no GitHub release exists; no release builds yet, build from source)
Last verified November 6, 2026. Listings are informational. The evidence score measures public, verifiable evidence and is not an endorsement or a compatibility claim.