cadgang
CAD viewer and markup tool whose model-anchored markups and joints are readable and drivable by Claude Code over MCP.
What it does and how it connects
CADgang is a CAD viewer and markup tool that opens STEP, IGES, BREP, STL, OBJ, PLY, 3MF, glTF, FBX and DXF files in a web page or a self-updating Mac app. It cuts, measures and sections models, and lets the user draw markups anchored on the model: pen, pencil, arrow, note, text and images. Claude Code can see those markups over MCP, so a circled edge means something to the agent.
It also models joints like Fusion: revolute, slider, screw, cylindrical, planar, ball and rigid joints between faces, with explode vectors solved from the joints so parts come off along their own axes. A drawing mode renders line-art views with dimensions in a title-block template and saves an HTML sheet. Earlier versions were a CAD authoring tool; from version 0.9 CADgang is the viewer, and the authoring code is tagged v0.8.0-alpha.28-full.
Try it at experiments.cwandt.com/cadgang by dropping a file on the page; the hosted copy cannot open paths on disk, while the Mac app and a local server can. It is built by CW&T with Claude Code. It has no license file in the repository, so no license is stated here.
Alternatives
Compare side by side- meshcue
A browser workbench for reviewing 3D models with an AI agent through pinned marks, rather than a viewer with joints, explode and drawings.
- agent-3d-workbench
A local 3D workbench where people and agents edit, model, verify and prepare prints, rather than a viewer and markup tool.
- open-poly
A browser-based open source CAD tool with a constraint solver and MCP access, rather than a viewer with model-anchored markups.
- parcad
Parametric CAD written as code with its own exact kernel and MCP surface, rather than a viewer.
- CADStudio
An AI-native parametric CAD environment for the web with an editable feature tree and CadQuery export, rather than a viewer.
Sources
Not verified
- License (no LICENSE file in the repository and no license stated in the README)
- Pricing (no price stated)
- Real user voices (the repository's recent issues are maintainer pull requests)
- Related Error Index entries (no entry verified for this tool's generic viewer scope)
- A named individual builder beyond CW&T
Last verified November 6, 2026. Listings are informational. The evidence score measures public, verifiable evidence and is not an endorsement or a compatibility claim.