kernelCAD

Use this when you need to add a mate connector to a part. Durably insert `<partBinding>.connector(name, { type, origin, axis?, normal? })` before the final top-level return. Use the part binding returned by add_part. Returns modified source plus diagnostics from re-evaluation. Side-effect-free.

Use this when you need to add a sketch constraint to a list. Append one validated sketch constraint to a constraint list. Side-effect-free: pass { constraints, constraint } and receive the updated list.

Use this when you need a freeform/organic 3D curve — a body feature line, brow, spine rail, or G2 blend between panels — authored as a Curve3D into the user's .kcad.ts immediately before the last top-level return. One authoring path, selected by `kind`: - 'nurbs' — insert a `nurbsCurve(controlPoints, opts?)` declaration. Pass `controlPoints` as a Vec3[] (mm, at least 2 points). Optional NURBS knobs: `degree` (default 3), rational `weights`, explicit `knots`, `closed`. - 'hermite' — insert a `hermiteG2(a, b)` declaration: a quintic Hermite curve interpolating two endpoints with matching positions, tangents, and (optional) curvatures — bridges two curves with G2 continuity. Each endpoint is `{ point: Vec3, tangent: Vec3, curvature?: Vec3 }` in mm; tangent magnitude ~ chord length; curvature defaults to [0,0,0] (G1-only). The returned binding has type Curve3D (peer to Shape / Surface) — consume it via `add_variable_sweep` (spine input), `add_surface({ kind: 'boundary' })` (boundary curve), or downstream Curve3D-accepting features. Returns the modified code + diagnostics from re-evaluating. Side-effect-free. Each kind fails closed on its own missing required params.

Use this when you need to insert a new feature line into a script. Insert a new feature line into a kernelCAD script before the last top-level return statement. Returns the modified code as text plus diagnostics from re-evaluating the result. Side-effect-free. Primitives that accept faceLabels (box, cylinder, extrudeRect, extrudeCircle, extrudePolygon, extrudeRoundedRect) can receive `opts.faceLabels` in the inserted code — use `lookup_api` to see `featureKindFaceLabels` for the full value schema.

Use this when you need to author a mate-graph relationship into the source, selected by `relation` (default 'mate'): - 'mate' — a typed mate between two connectors ({ name, a, b, type, pose?, limitsDeg?, limitsMm? }). - 'coupling' — couple a driven mate to a source mate by ratio ({ driven, source, ratio, offset? }). - 'transmission' — a physical drive path across mates ({ name, kind, sourceMate, drivenMates, path, ... }). All durably edit source and need { code, assembly_binding }. Params other than `relation` are forwarded verbatim; each relation fails closed on its own missing required params.

Use this when you need to add a part to an assembly. Durably insert `const <binding> = <assembly>.part(partName, shapeExpression, opts?)` before the final top-level return in a kernelCAD source string. Returns modified source plus diagnostics from re-evaluating it. Side-effect-free: caller persists the returned source.

Use this when you need a freeform/organic 2D outline — an eyewear brow, ergonomic grip, sneaker midsole, or body silhouette — by appending a curved segment to an existing PathBuilder chain on the named `chain_anchor` variable. The call is injected at the END of the chain, immediately before any `.close()`. One segment kind, selected by `kind`: - 'spline' — `.spline(points, opts?)`: interpolates through every `points` waypoint (Vec2[] mm, >= 2 entries; points[0] must match current pen position). Optional `tension`, and `startTangent`/`endTangent` 2D direction vectors that constrain the first-derivative direction at the endpoints (magnitude normalised internally). Use for organic 2D outlines (eyewear brow, ergonomic handle, sneaker midsole). - 'nurbs' — `.nurbsSegment(controlPoints, opts?)`: explicit B-spline net (Vec2[] mm, >= degree+1 entries; controlPoints[0] must match pen; pen ends at controlPoints[N-1]). Optional `degree` (default 3), rational `weights` (strictly positive), explicit `knots` (length = controlPoints.length + degree + 1). - 'hermite' — `.hermiteG2(a, b)`: each endpoint `{ point: Vec2, tangent: Vec2, curvature?: Vec2 }` in mm (a.point must match pen; pen ends at b.point). `curvature` defaults to [0,0] (G1); pass matching curvatures for G2 blends. Tangent magnitude is the first derivative (~ chord length), NOT unit length. Returns the modified code + diagnostics from re-evaluating. Side-effect-free. Each kind fails closed on its own missing required params.

Use this when you need to repeat a feature in a pattern. Insert a Shape.patternLinear / .patternCircular / .patternGrid call into a kernelCAD script before the last top-level return. Pass structured args (kind + the matching spec object). Returns the modified code plus diagnostics from re-evaluating. Side-effect-free. The pattern feature is a single editable unit; pattern-instance face refs resolve via `<sourceId>_pattern_<i>` on the pattern feature's lineage. Geometric note: pattern is implemented as cumulative boolean union of transformed source copies — additive features (boxes, ribs, fins, spokes) pattern cleanly; patterning a subtractive feature (hole, cutout) only preserves the per-instance void when adjacent bodies are disjoint.

Use this when you need an organic, freeform, or swept shape — a body shell, panel, fairing, ergonomic curve, lens, or sculpted form — authored as a NURBS Surface into the user's .kcad.ts, OR when you need to finish surfaces into a watertight solid or taper faces for moldability. One authoring/finishing path, selected by `kind`: - 'nurbs' — insert a nurbsSurface(...) / surfaceFromCurves(...) call. Pass either { controls, degree, weights?, knots?, periodic? } for direct construction, OR { section_sketch_ids } for skinning. Weights are honored: supply rational weights to build exact circles/cylinders/spheres/conics (the surface becomes rational); omit weights for a non-rational surface. - 'boundary' — insert a surfaceFromBoundary([c1,c2,c3,c4], opts?) call: one NURBS face through 4 boundary Curve3D refs (bottom, right, top, left in loop order; adjacent endpoints must coincide within 1e-6 mm). - 'trim' — insert a `<surface>.trimTo(<by>)` or `<surface>.split(<by>)` call. Pass `surface_binding` (the Surface variable name), `by_binding` (the cutter Surface variable name; Shape/Curve3D cutters are deferred to a later slice), and `op: 'trim'` (keep the largest imprinted piece) or `op: 'split'` (return both halves as a `[Surface, Surface]` tuple). - 'sew' — insert a `sew([s0, s1, ...], opts?)` call to stitch N surfaces into a closed watertight solid. Pass `surface_bindings` (array of Surface variable names). Use after trim/boundary to close patches into a solid: trim → sew → solid pipeline. Optional `tolerance` (mm, default 1e-6) and `require_closed` (emits feature.surface-sew.open-shell if result is not watertight). - 'draft' — insert a `<shape>.draft(angleDeg, { face, neutralPlane?, pullDir? })` call to taper the selected face(s) for mold release. Pass `shape_binding`, `angle_deg` (0–90), and `face` (canonical name, label, or FaceQuery descriptor). Lowering emits feature.draft.failed on invalid geometry. The returned Surface produces no Shape until you chain .thicken(t) or…

Use this when you need to author text into a kernelCAD script before the last top-level return. One authoring path, selected by `mode`: - 'sketch' — insert a sketch.text(...) call. The emitted sketch is chainable: pair with subsequent .extrude(...) / cut(...) edits to land an engraved or raised text feature. - 'emboss' — insert a `<shape>.embossText({...})` chained call onto an existing Shape `target`. Use for engraved brand text on faces (Ray-Ban temple, CE mark, model number). `depth > 0` raises text out of the face; `depth < 0` engraves text into the face. Lowers via replicad drawText → sketchOnFace → extrude → fuse|cut. Default font is the runtime-bundled Liberation Sans. Side-effect-free; returns the modified code plus diagnostics from re-evaluating. Each mode fails closed on its own missing required params.

Use this when you need an organic swept solid whose cross-section changes along its length — a tapering body, horn, bottle, handle, ring band, fairing, or duct — authored as a variable-section sweep along a spine. Inserts `variableSweep(spine, sections, opts?)` into the .kcad.ts `code` immediately before the last top-level return (an empty `code` starts a new script that returns the sweep). Spine: EITHER `spine_points` ([[x,y,z], ...] in mm, interpolated with spline3d; `spine_closed: true` closes the loop for a ring) OR `spine_binding` (an existing Curve3D / Sketch / Vec3[] variable). Each section: `t` in [0, 1] plus a profile — inline `radius` (circle) or `width` + `height` (rectangle), or `profile_binding` (an existing Sketch); profiles are centred on the spine and turned to face along it. Sections are strictly increasing in t, first t=0, last t=1 (omit t on every section to space them evenly). On a closed spine t=1 is the seam and reuses the t=0 profile. Example: { code, spine_points: [[0,0,0],[0,10,30],[0,0,60]], sections: [{ t: 0, radius: 8 }, { t: 0.5, radius: 10 }, { t: 1, radius: 4 }] }. Returns the modified code, diagnostics from re-evaluating it, and `sweep` { volumeMm3, bbox } measured from the built solid (ok:false when the sweep built nothing). The result is a Shape binding: return it, or chain `.union(...)` etc. via add_feature. Orientation is not exposed by this MCP tool until runtime orientation support is wired. Side-effect-free.

Use this when you need to declare a reachability target for a connector. Durably insert `<assembly>.workspace(connectorRef, { reachable, toleranceMm? })` before the final top-level return. Workspace targets are checked by solvedModel validation/review pose-envelope gates. Returns modified source plus diagnostics from re-evaluation.

Use this when you need to author and evaluate a fillet or chamfer on a kernelCAD Shape. Inserts Shape.fillet(radius, selector, { continuity: G1|G2 }) or Shape.chamfer(distance, selector) through the existing public API and returns the patched source plus evaluation diagnostics. Selectors accept EdgeSelector syntax, including canonical edge refs/query strings or { face: canonical name, face label, or face query }. G2 continuity applies to fillets; chamfer uses the existing chamfer API. This authors the operation and does not extract blend-surface NURBS poles; that still requires kernel surface extraction.

Use this when you have a list of parts with bounding boxes and positions (from a layout, spreadsheet, another tool or a sketch) and need an evaluable placeholder assembly script. Pass parts as { name, bboxMm:[x,y,z], positionMm:[x,y,z], rotationDeg?, anchors? } in mm; positionMm locates the bbox lower corner and anchors are named points in assembly coordinates. Optional connections [{ from, to }] reference anchors as "part.anchor" (including built-ins origin, bbox_center, bbox_x_min..bbox_z_max) and become fastened mates that express connectivity intent only; no wire or route geometry is generated. Returns the script (corner-anchored box solids with named connectors) plus warnings. It reads no files and cuts nothing; refine the solids with add_part/add_feature afterwards.

Use this when you need to render a script's animation timeline to a video, or a 360° turntable of a model for sharing. Capture a kernelCAD script's animationView({...}) timeline to an MP4 (ffmpeg) or a PNG frame sequence, verifying the sampled poses for part interference. FILE ONLY: pass { file } (a .kcad.ts path) — there is no { code } mode, because the capture engine renders from a file on disk (its relative lib.fromSTEP imports resolve against the script directory). MP4 by default; pass { frames_dir } to write frame-0000.png... and skip ffmpeg entirely (mutually exclusive with output_path). Animation-pose interference verification runs by default (keyframe times + segment midpoints) BEFORE any browser/ffmpeg cost; { no_verify: true } skips it and { verify_every: n } additionally samples every n-th frame time. Pass { focus } or { hide } (arrays of feature ids or assembly part names, mutually exclusive) to isolate parts in the rendered frames — same semantics as `kernelcad render --focus/--hide`; visibility is render-only and does NOT affect the pose verification. Collisions DO NOT fail the call — the artifact is still written as evidence with ok: true; read verified: false + the collisions[] array. TURNTABLE MODE: pass { turntable: true } for a seamless 360° orbit of the model (no animationView record needed) — a share-ready loop for a README, social post or product page. It uses the 'publish' studio look by default (same as render_preview preset: 'publish': key/fill/rim lights, soft contact shadow, clean backdrop, 30° lens, constant auto-framing over the whole orbit, light rig turns with the camera); { preset: 'default' } keeps the engineering look. Knobs: width/height (default 1080×1080, max 2048, even for MP4), duration_ms (one revolution, default 6000), fps (default 30), elevation_deg (default 22), background ('white' default, 'light', 'dark', 'black', '#rrggbb', or 'transparent' with frames_dir only), shadow (default true), environment. output_path ending in…

Use this when the goal is complex / production / enclosure / gearbox / robot-arm / multi-body, or when you need evaluate→review/verify→revise until green. PREFERRED over one-shot evaluate_script+open_in_studio for Adam-level parts. Runs a CAD design loop over attempt scripts: review_cad each attempt, continue past functional attempts with unresolved warnings, return repair prompts (nextActionPrompt) plus structured revisionAssist (suggestedPatches / autoApplied.suggestedCode for repairable feature failures; cookbook steers for stacked-primitive toys). Stop on ok or convergence.escalate. To pick among N alternative candidates for one goal without a judge, pass them all as attempts with consensus:true (geometric medoid selection). Optionally write a Studio build record JSON.

Use this when you need a manufacturability (DFM) report before printing or machining a part: returns a pass/fail checklist, no dfmSpec(...) needed. Pass { file | code } and optional processes (default ['fdm', 'cnc']). FDM 3D printing checks: fdm.overhangs (unsupported overhang steeper than max_overhang_deg, default 45° from vertical), fdm.bridging (bridges over max_bridge_mm, default 10), fdm.min-wall (walls under 2 × nozzle_mm, default 0.4 mm nozzle), fdm.min-hole (holes under 5 × nozzle), fdm.min-pin (warn), fdm.bed-fit (printer profile bed, default generic-fdm), fdm.bed-contact (warn). CNC 3-axis milling checks: cnc.undercuts (surface unreachable from approach_axes, default ['+z']; list several axes for several setups) and cnc.internal-corner-radius (sharp internal corners and fillets smaller than the end-mill radius, tool_diameter_mm default 6). Returns { ok, verdict: 'pass'|'fail', checks: [{ id, process, part, status: 'pass'|'fail'|'warn', summary, value?, limit? }], fdm?, cnc?, diagnostics }. Settings from the script's dfmSpec({ process: 'fdm' }) are used as defaults; call options win. For the script-declared gates (clearance, voids, channels) use verify({ check: 'dfm' }).

Use this when you need to know WHAT MATERIAL changed between two versions of a model, not just how much. The deeper sibling of diff_scripts: a volume delta alone is ambiguous (a boss that grew and a pocket that deepened report the same magnitude, and a part that only moved reports zero), so this tool answers it with geometry instead of pixels. Baseline is { baseFile } or { baseCode }; the revised side is either another script ({ file } or { code }) or the SAME script re-lowered with { params } overrides — a bag of declared param() name -> new value, which is the one-script form a parameter sweep actually asks for. Bodies pair by name and fall back to declaration-order positional pairing; anything left over is listed in `unmatched` and raises diff.body.unmatched. Per matched body it returns addedMm3 = volume(revised - base), removedMm3 = volume(base - revised), commonMm3 = volume of the overlap from boolean intersection, exact bbox with min/max/extent deltas, face / edge / hole count deltas (hole counts reuse the cylindrical-hole detector), maxDeviationMm (two-sided discrete Hausdorff distance between the two surfaces), and a `verdict` — identical | moved | resized | topology-changed, precedence topology-changed > resized > moved > identical. Branch on the verdict; cite the numbers. Optional { render: true } also writes an overlay PNG (added green, removed red, unchanged material as a translucent ghost; the scene is a re-runnable .kcad.ts over lossless BREP sidecars) through the render_preview pipeline and fails open (the numeric diff is still returned) when that pipeline is unavailable. Read-only — never touches the active session.

Use this when you need to see exactly what changed between two script versions. Structured geometric delta between two versions of a kernelCAD script — a baseline ({ baseFile } or { baseCode }) and a revision ({ file } or { code }). Returns agent-readable JSON: per-part added/removed/renamed/changed (volume mm³ + exact bbox deltas, numbers matching inspect({ of: 'part-stats' })), total interference-volume delta with per-pair detail, mate-graph changes (added/removed/changed mates incl. type, connectors, pose, limits), and param changes (value/min/max). Single-shape scripts diff as one "(root)" pseudo-part; a `return [a, b]` multi-body script diffs per body as "body[0]", "body[1]". An error that still leaves geometry (e.g. a skipped fillet) is listed under base/revised.errors beside the diff. Use after editing a script to verify exactly what changed physically before re-rendering. On a hosted server pass both versions inline: { baseCode: 'return box(10, 10, 10);', code: 'return box(10, 10, 12);' } (base_code/old_code/before and revised_code/new_code/after are accepted as aliases). Read-only — never touches the active session.

Use this when the reference for a part is a 2D engineering drawing PDF (orthographic views with dimensions), not a photo. Deterministic, no vision model: reads the vector linework (stroke width, dash) and positioned text; classifies visible / hidden / center / dimension / extension lines; reads the title block scale, units and projection symbol; identifies front / top / side views by projection alignment (third- or first-angle); ties dimension text to its lines (⌀, R, 4×, ±, THRU, depth). Dimension values win over measured lengths. Rebuilds the part as the view silhouette extruded by the depth an orthogonal view shows, or a turned part revolved from its half-silhouette, plus holes from ⌀ circles with THRU or hidden-line depth. Returns `script` — a `.kcad.ts` with role-named params (width, thickness, holeDia, hole1X, dia1, step1Length …) — and `ledger`, an assumption ledger where stated dimensions are `visible`, symmetry-derived positions `inferred`, defaults `assumed` and an unstated depth `missing`; a dimension that disagrees with the linework keeps its value and records the disagreement as an open fact. With verify (default) the script is evaluated, re-projected through the svg-drawing view stage and compared: `fidelity.verdict` is match | partial | mismatch | failed with per-axis extents, hole diameters and per-view silhouette IoU. Pass `out` to write the script and its `<stem>.ledger.json` (resolve open facts with resolve_assumptions, then set_param). A scanned (raster-only) page fails with reference.drawing.raster-only — use trace_from_image for those. Hosted: give the file as an https:// URL, a data: URI (base64, max 25 MB) or "asset:<id>" from request_upload (when the file is on the user's device).

Prepare an indicative estimate and durable manufacturing checklist for a whole CAD assembly, including mixed materials and processes. The server reads material and sheet thickness from CAD, selects supported processes, checks live supplier offers, and reports any missing prices or blockers. This creates only a draft estimate. It does not send an order, charge the customer, or start checkout. Sign in to estimate private saved projects; source code and public projects can be estimated as a guest.

Use 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…

Use this when you need to sample a signed-distance field at a point. Sample the signed distance from an in-script sdf.* field at a 3D point. Returns { distance, inside, aabb, kind }. Distance is in mm; negative = inside the surface, 0 = exactly on the surface, positive = outside. Use this to verify SDF composition before calling sdf.materialize (which is the expensive step). The script must bind the SdfField via sdf.bind('<name>', field) and pass that name as fieldName. Hint: pass either { file } or { code }, plus { fieldName, point: [x,y,z] }.

Use this when you need evaluate_script (and optionally open_in_studio) for an industry / cookbook demo in ONE step — after lookup_cookbook for industry demos, prefer execute_cookbook when you need evaluate+Studio together; empty lookup is not a stop (freehand-author instead). Resolves a cookbook snippet by `id` or BM25 `query` (same ranking as lookup_cookbook), evaluates its body via evaluate_script with bounded vendor timeouts, and returns explicit status with stage resolve|evaluate|open_in_studio. Pass openInStudio:true to publish the same script via open_in_studio after a green full evaluate (hosted MCP). dryRun:true is the fast capture-only path — it is NOT evidence the cookbook builds a solid or is safe to publish; finish with dryRun:false (default) before claiming success or opening Studio.

Use this when you need an ordered exploded-view plan for an assembly. Supply parts as {name,center:[x,y,z],size:[x,y,z]} in mm. Optional assembly_order sets the sequence; missing order falls back to input part order, and unlisted/unknown order refs are reported. Choose mode axis (default) or radial; axis follows the requested direction, radial moves parts away from the assembly centroid. The result includes ready-to-paste param_declarations, animation_tracks and reverse_animation_tracks for animationView(), part_transforms for existing shapes, and script_fragment. cameraPlan gives framing guidance.

Use this when you need to export geometry to a file. One exporter, selected by `target`: - target:'model' — export the script geometry to one file. Pass { file | code }, a required { output_path }, and { format }. Supported formats: stl (binary STL mesh), step (BREP CAD interchange), dxf (2D cut file for laser / waterjet / CNC: a flat part — plate, panel, extruded profile, in any orientation — exports its outline and holes in its own plane with exact arcs and circles; a sheet-metal part or a returned Region exports its flat pattern; a flat or sheet-metal part also returns sheet { thickness_mm, bend_count }, which a shop needs and the DXF does not carry; options.section { axis: "x"|"y"|"z", at } exports the cross-section of any part in world coordinates (plans, profiles); a multi-part model (cut list) writes all parts side by side on output_path, one layer per part, plus parts/<part>.dxf per part (reported in part_files; options.layout 'sheet' writes the combined sheet only); any other part fails with export.dxf.non-planar), 3mf (slicer-friendly mesh: one named object per part, colours as core-spec basematerials named by the part's engineering material; options.arrange 'plate' packs parts on the bed at Z=0 without overlap (options.orient puts each part's largest flat face down), 'assembled' keeps them together as one multi-part object for multi-colour prints; options.slicer 'bambu' | 'orca' | 'prusa' adds that slicer's per-object name + filament-slot sidecar — slot N is the Nth distinct colour/material), options.infill { fromFea: '<study>' | true, bands?, pattern? } = stress-graded FDM infill (requires the local CalculiX + gmsh toolchain; without it the export fails with fea.solver.unavailable): solves the feaStudy and writes modifier volumes, each with its own infill density (Orca/Bambu format by default; options.slicer 'prusa' writes PrusaSlicer's format instead, since the two are not interchangeable); the result carries infill { bands, saving, images }), gcode (i…

Use this when the user wants to get a part made: packages the fabrication files into one directory plus a zip, and returns links to public instant-quote pages. Pass { file | code } and output_dir; optional scope ('part', default — one script's files; 'bom' — the whole assembly's BOM: per-part single-body files, per-part drawings, bom.csv/json and vendor handoff texts; 'workshop' — part pack plus cut-list CSV/JSON, DXF flats.zip, and dfm_review JSON sidecar), name (default 'part'), formats (default step, stl, 3mf, pdf-drawing, bom-csv; add 'dxf' for flat/sheet; workshop also cut-list-csv/json, dfm-json, flats-zip), and processes ('3d-print' | 'cnc' | 'sheet-cut') to filter the links (bom: also narrows which fabricated rows are packed). Each file is written by the export tool, so its gates apply; a format that fails is reported in files[] and the rest still ship. Also writes manifest.json and README.txt. quote_links lists JLC3DP, JLCCNC, PCBWay, Xometry, SendCutSend and Craftcloud with the pack file to upload to each. One body per file: multi-body files are rejected by every shop. DXF is written only for flat or sheet-metal parts. The McMaster handoff text carries part numbers only, because McMaster quantities are packs and pack sizes are not in the catalog yet. These are plain web pages: nothing is uploaded or ordered. The user opens the link and uploads the file. Run dfm_review first if you have not. Hosted server: pack files are written on the kernelCAD server and returned in downloads[].url; nothing is uploaded to a fabrication service.

Use this when you need a structural check's context without paying for a solve. Read-only: returns the stored summary of a previous run_fea (pass the same `output_dir`), whether the CalculiX + gmsh toolchain is available on this machine (with the install command when it is not; run_fea then uses its in-process voxel solver — toolchain.default_solver says which), and the FEA material table with real E / Poisson / yield numbers so a grade is chosen against data rather than from memory. Never meshes, solves, or writes.

Fetch one bundled catalog part. Prefer `await lib.standard.nema17()` and `await lib.standard.bearing608()` — they are offline and do not download remote STEP. A lookup that cannot finish fails within 45s with errorCode parts.lookup.timeout. Do not retry in parallel.

Search the bundled parts catalog (offline). For a NEMA-17 motor write `await lib.standard.nema17()`; for a 608 bearing write `await lib.standard.bearing608()`. Do not fan out parallel lookups and do not pass partsBaseUrl unless you set source:"remote". Remote lookups fail within 45s with errorCode parts.lookup.timeout instead of hanging.

Use this when you need to fit an orthogonal least-squares plane to XYZ point-cloud data. Returns centroid, deterministic unit normal, signed point residuals, RMS residual and maximum absolute residual. Accepts points already parsed by the caller from scan data or mesh vertices. Computes parameters only; it does not create a surface body. Requires at least three non-collinear finite points.

Use this when you need the unfolded flat pattern of a bent sheet-metal part. Return the unfolded 2D flat-pattern of a bent sheet-metal Shape as a Region (outer polyline + holes + bend lines + sketch plane). Any number of parallel bends; crossing bends need corner relief. Pass { file } or { code }; optional { featureId } to pick a specific Shape.

Fetch one public catalogue asset by slug. Read-only. No sign-in and no API key. Returns the search fields plus params (the knob schema), presets, rig, and public download paths. UNITS: metres, Y is up. stats.size_m and stats.origin_y are metres. RIG: each rig entry is a named pivot. type "rotate" has range in degrees; type "slide" has range in metres; axis is the pivot's local x, y or z. license is the SPDX id to keep with the asset. The download paths are public catalogue routes. Call get_asset_pack for a short-lived signed zip URL. Do not send an API key.

Return a short-lived signed URL for a catalogue asset zip (mesh, params, licence). Read-only. No sign-in. The URL is already signed. Fetch it with GET. Do not send an API key or an Authorization header. It expires quickly; read expires_at. Share download_url with the user. Units in the pack follow the catalogue: metres, Y is up. A rig, when present, names pivots of type rotate (degrees) or slide (metres). If the publisher stored no pack, the result is { ok: false, error: "not_stored" }.

Render a project's current model server-side and return it as an inline image so you can SEE what you built. Prefer open_in_studio for the happy path — it already includes an iso PNG preview in the same publish result when previewDelivered is true. Use this tool for a different `view`, a contact sheet (`view:"all"`), or when you only have a slug and are not publishing. Call with that `slug` to inspect whether the build looks right. CRITICAL — the image is rendered from the MODEL on the server; it does NOT reflect the user's Studio camera, zoom, or screen. NEVER ask the user to rotate, zoom, pan, move the camera, close a slider, or change their view to help you see — you cannot affect their screen and it cannot affect this render. To see a different angle, call this tool again with a different `view`. By DEFAULT (omit `view`, or `view:"all"`) it returns a CONTACT SHEET of all six canonical views in one labeled image — a 3×2 grid, top row [iso, front, right], bottom row [back, left, top] — so you can judge the model from every side regardless of its orientation (e.g. to find which side has the doors). Pass a single `view` (iso/front/back/left/right/top) for one large render of that angle. DETERMINISTIC: the same model + view always returns the same bytes — identical bytes are NOT a stale/lagging snapshot. If you changed the model, push it with open_in_studio FIRST, then re-render to see the change. The image is always current and never a blank capture. Colors and shading match Studio (same palette / base-material color). The slug is the capability: no OAuth for public/unlisted; private projects require the owner signed in. The PNG is base64-inlined as a real image block by default; pass `paths_only: true` for metadata only. No renderable geometry or a mesh failure → { ok: false, error, hint }, never a blank image. error "mesh_timeout" means the model took too long to build for a preview; the source is not wrong (it still exports) — do not rewrite it to fix the render.

Return the raw per-feature triangle mesh (positions/indices/normals) of a project's current model, by slug. For the in-chat 3D viewer widget to render geometry; delivered over the MCP Apps bridge. The slug is the capability: public/unlisted need no OAuth; private requires the owner signed in.

Use this when you need to reopen a saved project or browse what the user has saved — it fetches a kernelCAD Studio project, or lists the signed-in user's saved projects. Pass `slug` (from a /p/<slug> link or a prior listing) to fetch that project's full .kcad source and metadata — then edit and open_in_studio with the same slug so the user's open tab updates live. Private projects require their owner's OAuth connection. OMIT `slug` to list the signed-in user's saved projects (most recently updated first); that listing mode requires the OAuth connection and does NOT paint — prefer list_my_projects to find a project to continue. Read-only: this tool never shows a viewer (only open_in_studio does, once per response). Paint phases: projectSaved/meshReady reflect fetch state; viewerPainted stays false. Use open_in_studio (with code) to publish+paint — do NOT call get_model_mesh or get_latest_render for interactive paint.

Fetch the exact immutable .kcad source and parameters captured at a prior `open_in_studio` version. Use this to read-after-write verify a release: pass the returned `slug` and `version`, then hash or inspect the returned source. Public/unlisted projects use the slug as capability; private projects require the owner's OAuth connection.

Use this when you need to read the human/agent selection in a local Studio session. Returns one clicked face or edge (or null), with current-generation mesh-local shapeIndex/kind/id and creating featureId. During a rebuild selection is null with “selection pending rebuild” until Studio uniquely verifies the face; ambiguous or deleted faces are cleared. Inspect the current shape before authoring a fillet. Requires a running local Studio opened on the same script; hosted sessions are not supported.