Roshera-CAD
Agent-native Rust geometry kernel where every operation returns a validity certificate against structural invariants.
What it does and how it connects
Roshera is an agent runtime for geometry: a native Rust B-Rep kernel with a semantic surface an AI can query, reason about and act on. Every operation returns a validity certificate, a nine-conjunct check over B-Rep validity, watertightness, manifoldness, orientation, self-intersection, construction and feature consistency and two mesh-quality dimensions, computed synchronously under the model write lock and failing closed. The README's headline is that the kernel cannot lie.
A separate fidelity report compares requested against measured quantities beside the certificate, never folded into the sound verdict: a loft that was certified sound while 9.97 percent short of the requested cross-section is the case that proved the gap. An MCP server exposes the kernel to agents behind six typed dispatch gates, including an intent gate, an unsound-base gate and a verification-scope gate, and an evidence pack bundles a document's history, certificates and notebook for review.
The repository also carries a React and Three.js browser client, STEP AP242 export and import, certified 2D drawing sheets, an event-sourced timeline and a certificate-scored agent evaluation harness. It is a work in progress: the README's own status table marks several areas implemented but lightly tested, and its RL episode loop has a task corpus of one task with no language model having driven an episode yet. The license is the Functional Source License 1.1, which converts to Apache 2.0 after two years.
What engineers report
On a thin wavy cylinder band, validate reports the B-Rep valid and watertight, but certify_solid fails manifold, oriented, self-intersection-free and mesh-quality checks, with 10 non-manifold mesh edges.
2026-09-29Read the original
Alternatives
Compare side by side- parcad
Parametric CAD written as code with its own exact kernel and MCP surface, rather than a Rust B-Rep kernel with validity certificates.
- open-poly
A browser-based open source CAD tool with a constraint solver and MCP access, rather than a Rust geometry kernel.
- CADStudio
An AI-native parametric CAD environment for the web with an editable feature tree and CadQuery export, rather than a Rust kernel.
- vibe-cading
CadQuery-based 3D model generators written for humans and LLM agents, rather than a Rust B-Rep kernel.
- cadgang
A CAD viewer and markup tool whose markups and joints are readable by Claude Code over MCP, rather than a geometry kernel.
Sources
Not verified
- Pricing (no price stated; source available under FSL-1.1)
- Related Error Index entries (no entry verified for this tool)
Last verified November 6, 2026. Listings are informational. The evidence score measures public, verifiable evidence and is not an endorsement or a compatibility claim.