kernelcad-mcp

kernelCAD — MCP companion

When to load this skill

Load when kernelcad mcp is available and you need to inspect or edit a live model without re-running the full CLI on every change. The MCP server exposes dynamic introspection tools that operate on evaluated in-memory state.

MCP tool surface

When you have kernelcad mcp available, use the MCP tools for dynamic introspection rather than re-running the CLI. The MCP server exposes the current tool registry, including:

Evaluation and introspection

• evaluate_script({ file? code?, dryRun? }) — pass/fail + featureCount + diagnostics; plus a parts summary { count, names } when the scene is assembly-built (absent for single-shape / non-assembly scripts). dryRun: true is the fast iteration mode: transpile + capture + capture-light checks WITHOUT OCCT lowering, DFM gates, or meshing — milliseconds instead of seconds. A dry run catches script throws, capture-time API misuse, and assembly validity-gate failures, but NOT lowering failures (failed booleans, oversized fillets) or dfmSpec diagnostics, and it leaves the active session untouched — finish with a full evaluate_script before using session-dependent tools.
• diff_scripts({ baseFile? baseCode?, file? code? }) — structured geometric delta between a baseline script and a revision. Returns per-part added/removed/renamed/changed (volume mm³ + exact bbox deltas; numbers match inspect({ of: 'part-stats' })), interference totals per side + deltaMm3 with per-pair detail, mate-graph changes (type, connectors, pose, limits), and param changes (value/min/max). Single-shape scripts diff as one (root) pseudo-part. Use after editing a script to verify exactly what changed physically before re-rendering; read-only, never touches the active session.
• inspect({ of: 'features', file? code? }) — array of feature summaries (kind/id/params/inputs)
• inspect({ of: 'assemblies', file? code? }) — captured assembly intent: assemblies, parts, named connectors, fixed connections, joints, and aggregate models
• inspect({ of: 'assembly', file? | code?, assembly? }) — physical assembly inventory for agents: named parts, bboxes, connectors, mates, mechanical review facts, disconnected solids, unexplainedGeometry, and a next-action prompt. Run this before accepting visually suspicious mechanisms; random/floating geometry must be repaired or explicitly justified by the original prompt.
• inspect({ of: 'step', file }) — inspect a STEP file directly, without evaluating a script ({ file } is required; no { code } mode): solid tree (index + best-effort name), per-solid exact bounding box + volume + face count, and detected cylindrical holes (axis origin + direction, diameter, depth, blind/through; co-axial seam-split faces merge into one bore). Run this before placing an imported vendor part — find mounting-hole positions and verify the part-local frame from exact geometry instead of measuring renders. CLI equivalent: kernelcad inspect step <file.step>.
• inspect({ of: 'shape', file? code?, feature_id? }) — volume/surfaceArea/bbox of a feature (default: last)
• inspect({ of: 'topology', file? code?, feature_id? }) — canonical face names + edge count
• inspect({ of: 'face-edges', file? code?, feature_id?, face_name }) — boundary edges of a face (centroid, length, isClosed)
• inspect({ of: 'edges', file? code?, feature_id? }) — enumerate all edges (index, centroid, length, isClosed)
• inspect({ of: 'faces', file? code?, feature_id? }) — enumerate all faces with area and centroid
• inspect({ of: 'face-labels', file? code?, feature_id? }) — canonical face names resolvable on a feature
• query({ mode: 'lineage', file? code?, feature_id, ref }) — walk the HistoryMap chain that produced a named face/edge ref; returns { chain, usedFallback }.