C33D
Browser based AI-native parametric CAD research preview where an LLM agent authors designs as an editable node graph executed on the OpenCascade kernel in WebAssembly, with geometry percepts feeding an auto-repair loop and STEP export.
What it does and how it connects
C33D is a browser based, AI-native parametric CAD system in research preview. You describe an object in chat, and an LLM agent architects it as a node graph. Because the output is a graph and not a static mesh, the model stays fully parametric: dimensions can be tweaked, sliders dragged, and features remixed without breaking the design.
The engine runs OpenCascade through replicad in WebAssembly, producing robust B-Rep solids exportable directly to STEP for manufacturing or 3D printing. The pipeline runs chat, LLM planning, graph generation, a schema validation gate, execution in a web worker, geometry percepts returned to the LLM (volume, bounding boxes, face counts), and an auto repair loop that fixes the graph when geometry fails.
C33D uses a bring your own key architecture: API keys are entered once in the UI, stored only in the browser local storage, and never sent anywhere except the AI provider chosen. The README states nothing phones home, and it runs locally with Node 22.13 or later and a Gemini or OpenAI key.
Alternatives
Compare side by side- Agent-CAD
An open source AI CAD workbench that turns natural language into build123d solids and 2D drawings, rather than a browser research preview built on a node graph.
- build123d-mcp (pzfreo)
A CAD toolbox an AI app uses through MCP to build build123d models step by step, rather than a browser agent that authors node graphs.
- cad-gen (philinhphan/cad-agent)
Turns a technical drawing into CadQuery geometry with a self refine loop, rather than turning chat into a parametric node graph.
- AnkusDrive
A CLI and MCP server that drives FreeCAD with FEM and CFD simulation, rather than a browser preview on OpenCascade in WebAssembly.
- MecAgent
A commercial desktop copilot that acts inside an open SolidWorks session, rather than a browser based research preview.
Sources
Not verified
- Pricing: none stated on the repo. The tool uses the user's own AI provider key, so model costs sit with the provider.
- Website https://c33d.vercel.app, linked in the README as the hosted live demo, returns HTTP 402, so no website is listed.
- No GitHub releases exist, so latest release fields are null.
- No independent user voice found: the repo has no public issues listed via the API.
- Related Error Index entries (no matching entry verified)
Last verified November 6, 2026. Listings are informational. The evidence score measures public, verifiable evidence and is not an endorsement or a compatibility claim.