Note: Check out Helios, the reference browser CAD frontend for Aetheris in early alpha, if you want to try Aetheris out for yourself. Otherwise, tell your LLM agents to clone the repo and start vibe-CADing, because I'm too lazy to add an MCP server to Aetheris.

Gordian Knot - virtual sculpture, by Claude 5 Sonnet

See the Aetheris difference, designed/created by GPT-6 Astra.

Aetheris is a next generation open-source geometric modeling kernel/engineering runtime platform, currently primarily used for mechanical computer aided design (mCAD) applications, similar to Parasolid/ACIS/OpenCascade, developed solo by Yuechen Li with the assistance of GPT-5/6, Claude 4/5, and Gemini 3 from scratch over the course of the year 2026.

Think of it as the operating system for software such as SolidWorks/Creo/Catia/NX/Fusion 360/Inventor/FreeCAD, and long has it been considered "one of the most complex software engineering challenges, requiring deep expertise in computational geometry, topology, and numerical stability". This repo stands as the testament that it is now a solved problem.

Aetheris ships with Cadmata, a webpage-based viewer. Visual editor support currently in development.

Aetheris supports a variety of standard modules for different industries and manufacturing processes: sheet metal, weldaments, piping auto-routing, injection molding (alpha), advanced surfacing, wire forming, and virtual sculpting/3D art.

Automated design-for-manufacturing (DFM) checks, finite element analysis (FEA), GD&T style product manufacturing information (PMI), material/parts database, and 2D drawing/PowerPoint review slide generation are included runtime features.

Three Telos is the shared engineering display layer. It uses Three.js where Three.js is useful and replaces it where engineering visualization requires stronger guarantees. Reuse upstream data structures; own downstream GPU behavior. See Three Telos display.

Aetheris' native representation format is Firmament, a domain specific programming language designed specifically for 3D modeling applications. Unlike other CAD software, Aetheris is AI-native and so designed to be code-first, enabling full headless usage from the CLI.

Similar to OpenSCAD, the simplified core architecture description of Aetheris is that it's a compiler for 3D object, you can also think of it as LLVM for CAD. Unlike OpenSCAD, Aetheris emits 3D objects in exact boundary representations instead of SCAD's mesh. The native export format of Aetheris is industry standard STEP AP242, enabling full interop with any other 3D parametric CAD software.

Unlike most other vibe coded geometry kernel, C# and .NET are used as the primary development language/runtime from the beginning instead of Rust/C++ due to the strength of the .NET tooling and ecosystem instead of prematurely optimize for theoretical performance. As such, Aetheris is available for download on Nuget here.

Aetheris does not use 2D constraint solving as legacy CAD kernels do. Instead, inspired by TypeScript, constraints are defined ahead of time in code and erased at compile time.

Unlike the current industry standard reckless usage of non-uniform rational B-spline (NURBS), Aetheris uses exact analytical geometry as its foundation, the generated STEP artifacts are exact and requires no post-import healing/patching.

Dangerous operations which may generate degenerate/sliver/zero-dimension geometries are instead blocked from materializing to 3D at a compiler level.

Download a self-contained release bundle for Windows x64, Linux x64 or macOS Apple Silicon. Each includes the CLI, Cadmata browser viewer, Forge Host, documentation, examples and material catalog; no SDK or Node.js installation is needed. Follow the bundle walkthrough. For the CLI alone, install the managed .NET tool with the .NET 10 SDK:

dotnet tool install --global Aetheris.CLI --version 2.0.0
aetheris --version
aetheris build fixtures/Canonical/PMI/hole-diameter-and-datum.firmament --output artifacts/local/first-part.step --json
aetheris analyze artifacts/local/first-part.step --json

Go next to Getting Started, then Learn Firmament: six short lessons from a first part to an assembly. The documentation index has everything else, and the project history tells how Aetheris got here.

The machined mounting block is the canonical first serious CAD example;

See the L-bracket for the introductory Sheet Metal example;

See cantilever for the analytically interpretable meshless cut-cell FEA witness.

A qualified flat-pattern sheet metal artifact, created entirely by GPT 5.6 Sol with human guidance, including formed STEP, flat STEP, SVG, bend identity, material identity, and DFM evidence on the documented Sheet Metal routes.

$forgeHost = ".\forge-host\Aetheris.Forge.Host.exe"
& $forgeHost list
& $forgeHost describe Standard.SheetMetal.ElectronicsEnclosure
python .\samples\forge-interop-x1\python\client.py $forgeHost .\samples\forge-interop-x1\request.json .\out\forge-python

The bundle contains equivalent Go, Rust, and TypeScript clients. Forge Host Protocol v1 is independently versioned from Aetheris 2.0.0.

The managed CLI is qualified on Windows x64 and Linux x64. The self-contained desktop ZIP targets Windows x64; macOS is not a qualified release target. See the release notes for capability and experimental API boundaries.

Aetheris code is licensed under the GNU Affero General Public License v3.0. Alternative licensing is available on request. Third-party assets retain their own terms and provenance; see THIRD_PARTY_NOTICES.md.

Special thanks to the National Institute of Standards and Technology (NIST) for STEP AP242 test models used in development and validation. Their presence does not imply NIST endorsement or place those models under the Aetheris license. Stanford Bunny provenance is recorded separately in the third-party notices.

External contributions are welcome under the process in CONTRIBUTING.md. The proposed contributor license agreement is a candidate pending human attorney review and is not yet an operative acceptance mechanism.