Evaluate CAD Script
evaluate_scriptUse this when you need to run a script and check it compiles. Full local builds return viewerUrl: a live Studio link reused and updated on later full builds in the same MCP process. Hosted builds return viewerMode: hosted and viewerHint pointing to open_in_studio; they do not start a loopback viewer. Full evaluations return step evidence: build validity, volume and before/after local PNG paths in one shared iso frame. Snapshots require PW_CDP_URL for an existing browser; unavailable captures report an explicit error. Run a kernelCAD .kcad.ts script and report pass/fail + feature count + diagnostics + sceneSummary (BREP validity, volume in mm³, face count, bounding size in mm). When the scene is assembly-built (assembly().part(...) → .model()/.solvedModel()), also returns a parts summary { count, names } AND runs the mechanism-truth gate by default: the mechanism field reports real/broken/unverified and a broken mechanism (disconnected components / mechanism.orphan-part, self-collision, fastened drift, dof-mismatch) makes ok:false with the failures in diagnostics, as does a mate connector more than 6 mm outside its part bounding box (assembly.mechanical.connector-not-in-solid, the same error review_cad reports) — a mechanism (any mate or joint) needs every part linked by connectors + mates/joints (axis+revolute for shafts/hinges/gears; frame+fastened for rigid; or arm.revolute/.prismatic/.ball/.fixed). A plain multi-part assembly with no mates (base + lid, print layout) is independent bodies and passes. Pass { skipMechanismCheck: true } to opt out (e.g. a deliberately free part next to a mechanism). An animation or drive on a fastened joint (mechanism.motion-on-fixed-joint) is broken: animate a revolute/prismatic mate pose. For a model with moving joints or motion intent, mechanismSummary.statement is one plain line: "Motion checked: ..." names what ran; "Motion not checked: ..." is NOT a pass — never call that mechanism working. Every union() is checked too (no opt-out): union.disconnected (the union is several separate solids — a floating operand) and union.member-overlap (two operands that each carry their own .finish()/.material(), the same one, share > 1 mm³ — cut members to fit, e.g. a cross tube between rails is span minus two rail widths) make ok:false. Pass either { file: "" } or { code: "" }. Set { dryRun: true } for fast validation while iterating: transpile + capture + capture-light checks without building solids, DFM gates, or meshing — milliseconds instead of seconds (100x+ on boolean/fillet-heavy scripts). A dry run catches script throws, capture-time API misuse, and assembly validity-gate failures, but NOT lowering failures or dfmSpec diagnostics; it leaves the active session untouched, so finish with a full (non-dry) evaluate_script before using session-dependent tools. To show a measurement in the 3D viewer (e.g. hole spacing), declare it in the script with shape.dimension({ kind: "linear", from, to, label }); a full evaluate lists them as dimensions: [{ text, kind, source }], and a shared /p link with ?dims=1 forces them on. A full evaluation updates the active MCP session and viewer state and keeps temporary step evidence; { dryRun: true } leaves the active session unchanged. Hosted: lib.fromSTEP / fromSTL / meshFromSTL / fromDXF / fromSVG and referenceImage take a direct string literal or a const bound to one (computed expressions are unsupported). They accept "asset:" (from request_upload), an https:// URL or a data: URI as the path.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| code | No | Inline kernelCAD script source. | |
| file | No | Path to a .kcad.ts script file. Hosted server: cannot read files from your machine — pass `code`, or `project:<slug>` for a saved project. | |
| dryRun | No | Fast validation only: skip solid build, DFM gates, and meshing. Does not set or clear the active session. | |
| intent | No | The user's request in one sentence, in the user's own words and language (e.g. 'M4 bracket for a 25 mm tube, print on Bambu A1'). Helps kernelCAD improve; leave out personal data. | |
| kernel | No | Solid-modeling kernel. Default 'occt' (OpenCascade); opt-in 'smlib' uses guarded candidates with explicit OCCT fallback diagnostics. | |
| baseline | No | The `selections` of an earlier evaluation of this model. A selector that now binds to a different face or edge is reported as selector.binding-changed (warning), one whose entity only moved or resized as selector.binding-moved (info). Defaults to the previous evaluation of the same `file`. | |
| requirements | No | Call-time external requirements ([{ name, predicate }]) measured in the same `requirements` ledger, tagged source: 'external' and never persisted. The predicate is the serializable form of require(): { metric: clearance | distance | mass | volume | bbox | centerOfMass | count | innerLoops | angle | concentric | coplanar, a?, b?, op: gte | lte | eq | between | within, limit, tolerance?, density? }. Operands are { kind: body | faces | edges | part, ref: <feature id/name or part name>, query? }. | |
| skipMechanismCheck | No | Opt out of the default mechanism-truth gate. By default a full evaluation of an assembly-built scene runs checkMechanismTruth and returns a `mechanism` verdict (real/broken/unverified); a broken mechanism makes ok:false. Set true to skip the sweep entirely (no `mechanism` field, no cost). Ignored for dryRun and non-assembly scripts. |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||