The measurements come from Open CASCADE rather than from a model's impression of the shape, which is the difference between a design review and a guess. It is read-only by construction — it will report the wall thickness face by face and flag the undercut, and leave changing it to you.
An MCP server that reads STEP files with the Open CASCADE kernel on your own machine. It answers geometry questions with measurements rather than estimates — bounding box and volume, face and edge queries, thickness and draft, clearance between entity sets — and it never modifies the model. No CAD licence and no cloud upload.
- inspect_step — the compact overview to start from: dimensions, bounding box, body, face and edge counts, validity and watertight status, with optional bodies, quality, PMI, inertia and topology sections
- find_faces — faces by type, area, radius, normal, quality or body, returning IDs, surface types, areas, radii, diameters, axes and normals for use in the measurement tools
- find_edges — edges by curve type, length, radius or dihedral angle, returning IDs, lengths, radii and diameters
- measure_distance — distance between two sets of entities, such as the clearance between holes and walls, with a minimum summary for the closest pair
- measure_thickness — wall thickness across faces by ray-grid sampling, reported as min, max and average per face
- measure_draft — draft angles relative to a pull direction, with the normal and an undercut flag per face
- measure_geometry — ray tests, point analysis, cross-sections and edge continuity, selected by measurement type
- diff_step — two STEP files compared: deltas in volume, surface area, dimensions and face, edge and body counts
Node.js 24 or newer and a STEP file exported from SolidWorks, FreeCAD, Fusion 360, CATIA or any other CAD system. Clients run npx -y cad-mcp-server over stdio. The OCCT kernel is bundled, so there is no CAD software, licence, Docker or cloud API involved, and the files stay on your machine.
One command — npx -y cad-mcp-server