kernelCAD

com.kernelcad/kernelcad · v0.17.1

CAD in ChatGPT and Claude: editable parts, STEP/STL/drawings, in-chat 3D, automatic checks.

Website Source code Set it up

Connect Remote server

Terminal

claude mcp add --transport http kernelcad https://mcp.kernelcad.com/mcp

~/.cursor/mcp.json

{
  "mcpServers": {
    "kernelcad": {
      "url": "https://mcp.kernelcad.com/mcp"
    }
  }
}

.vscode/mcp.json

{
  "servers": {
    "kernelcad": {
      "type": "http",
      "url": "https://mcp.kernelcad.com/mcp"
    }
  }
}

Claude Desktop

Settings > Connectors > Add custom connector
URL: https://mcp.kernelcad.com/mcp

Tools 80 found in our last check

review_paint_peek_latest
Return the newest brush-painted review packet from a Studio session. After sharing a /p/<slug> link, the user can open it in the browser and paint marks over the 3D viewport to give visual feedback. Call this tool with the `slug` from that link to see the strokes — screenshot +…
open_in_studio
Save the model as a kernelCAD project AND show it: persists a project revision, returns the interactive Studio viewer (MCP Apps / ChatGPT outputTemplate), and includes a PNG preview in the SAME tool result (image content + previewUrl when available). For a new private model pass…
get_project
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…
get_project_revision
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 capabilit…
get_latest_render
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…
get_model_mesh
Return the raw per-feature triangle mesh (positions/indices/normals) of a project by slug. Pass version for an exact immutable revision; omission reads the current model. The result echoes slug and version. For the in-chat 3D viewer widget to render geometry; delivered over the…
request_upload
Use this when the user has a photo, PDF drawing, STEP, STL, DXF, SVG or 3MF file on their device and you need it in a kernelCAD tool (trace_from_image, drawing_to_cad, mesh_to_features, inspect of:"step", or lib.fromSTEP / fromSTL / fromDXF / fromSVG / referenceImage in a script…
lookup_authoring_skill
Return the kernelcad-authoring skill — conventions for writing .kcad.ts scripts (API surface, parameters, evaluation contract, common pitfalls) — in sections. Call with NO arguments first: you get the quick-start (units, axes, the return rule, the rules that prevent most failure…
mesh_summary
Mesh a kernelCAD .kcad.ts source server-side and return a COMPACT geometry summary — overall bounds plus, per feature, its id, kind, triangle count, and bounding box. Use this to INSPECT a model's geometry without a viewer: confirm a part is the size/shape you expect, see how ma…
report_need
Use this when the user needed something kernelCAD does not have, so the gap is recorded instead of papered over. kind: asset (search_assets returned coverage none or poor: the catalog does not model it), capability (a tool cannot do what was needed), output (a tool answered, but…
netlist_export
Build the electrical netlist from a schematic — the flat connectivity of every component pin and net, the way KiCad's netlist export works. Use this to turn a schematic description into machine-readable connectivity: which pins share a net, what each component connects to, and w…
netlist_query
Ask a net-level question about a schematic: what connects to what. MODES (`query`): • "net" — the full membership of one net (`net` required). • "pin" — which net a component pin is on (`component` + `pin` required). • "component" — every net a component touches (`component` req…
erc_run
Run an electrical rule check (ERC) on a schematic and return structured diagnostics — the KiCad ERC step, over MCP. CHECKS: duplicate reference designators; net endpoints naming an unknown component or pin; unconnected pins (ignoring hidden power pins and explicit no-connects);…
search_assets
Search the public kernelCAD asset catalogue of published models. This is not find_part (screws, bearings, NEMA). Read-only. Anonymous callers are allowed. Do not send an API key. Use source:"library" for the free built-in model library. Search its titles, tags or kit IDs, and do…
get_asset
Fetch one public catalogue asset by slug. Read-only. No sign-in and no API key. A built-in kit/id returns the free editable downloads.source (.kcad.ts), studio_url, thumbnail_url, license, and published params and presets. params lists each declared control with its name, type,…
get_asset_pack
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…
evaluate_script
Run a script and check the built model against its declared requirements. A full result has buildOk for geometry availability and ok for overall acceptance: a failed or not-evaluated requirement makes ok:false while retaining built geometry for inspection. Full local builds retu…
diff_scripts
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/re…
inspect
Use this when you need to read facts about a model. One reader, selected by `of`: - 'assembly' — physical assembly inventory (parts, bboxes, connectors, mates, disconnected solids). - 'robot' — URDF/SDFormat export preview (links, joints, planning groups, end-effectors, issues).…
verify
Use this when you need to check a design against a rule set. One verifier, selected by `check`: - 'assembly' — static assembly review ({ file | code }, or the session evaluate_script left): mate validator, default-pose interference, joint topology, mechanical plausibility. ok:fa…
why_did_this_fail
Use this when you need to trace why a feature failed. Walk the upstream chain of a failing feature. Returns the diagnostics of the requested feature plus the diagnostics of every upstream feature in topological order (the requested feature is the last entry). Per-code hints are…
set_param
Use this when you need to edit a param() default value in a kernelCAD script. Returns the modified code as text plus diagnostics from re-evaluating the result. Caller persists the new code via standard file-write tools (this tool has no side effects). With preview: true it build…
add_feature
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. Direct editing is authored here too:…
add_surface
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.…
add_curve
Use this when you need a freeform/organic 3D curve — a body feature line, brow, spine rail, or curve bridge between panel boundaries — authored as a Curve3D into the user's .kcad.ts immediately before the last top-level return. One authoring path, selected by `kind`: - 'nurbs' —…
add_path_segment
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, immedi…
trace_from_image
Use this when you need to trace a reference image into normalized waypoints. Trace pixel-space features from a reference photo into normalized [0..1] waypoints the agent can map to mm via a known scale anchor and feed to path().spline / path().nurbsSegment. Three backends are di…
add_variable_sweep
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…
add_text
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 en…
project_curve
Use this when you need to wrap a 2D closed curve onto a 3D face. Insert a `<shape>.projectCurve({ source, face, scaleMode? })` chained call into a kernelCAD script. The `source` is the structured `{ kind: "sketchCommands", commands: [...] }` wire format the runtime API accepts.…
add_pattern_feature
Use this when you need to repeat a feature in a pattern. Insert a Shape.patternLinear / .patternCircular / .patternGrid / .patternCurve call into a kernelCAD script before the last top-level return. Pass structured args (kind + the matching spec object). Curve patterns use equal…
remove_feature
Use this when you need to remove a feature line from a script. Remove a single line from a kernelCAD script identified by a substring match. Returns the modified code plus diagnostics from re-evaluating. Refuses to remove the line containing the return statement. Side-effect-fre…
query
Use this when you need to resolve or inspect topology against a script's lowered geometry. Pass the script as `code` (inline; works on a hosted server) or `file`. Selected by `mode` (default 'evaluate'): - 'evaluate' — list the faces a Query matches ({ query }). Pass expect:'uni…
lookup_api
Look up the kernelCAD script API by query (symbol or keywords) and/or section. Results contain exact runtime signatures and are bounded and paginated. Omit query and section for a compact first page and section index. Continue with next_offset as offset and the same query/sectio…
lookup_diagnostics
Use this when you need the kernelCAD 26-code diagnostic catalogue with hint templates. Tiny one-shot call; useful for an agent that wants to pre-populate retry strategies. Hints are also inline on every emitted diagnostic — this tool just gives you the canonical list up front.
export
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 intercha…
lookup_cookbook
Use this when you need a canonical pattern snippet for a CAD task. Search the kernelCAD cookbook for canonical pattern snippets. Returns top-k snippets matching the natural-language query, ranked by BM25 over title/tags/keywords/trigger. Use when you need a canonical pattern for…
find_part
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…
fetch_part
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.
solve_sketch
Use this when you need to solve a 2D sketch constraint set. Solve a 2D sketch constraint set. Side-effect-free: pass { entities, constraints } and receive solved entities plus the original constraints. Entities are POINT, LINE, and CIRCLE records; constraints use the kernelCAD c…
add_constraint
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.
add_part
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-f…
add_connector
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. S…
add_mate
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…
add_workspace_target
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. Return…
set_scene_return
Use this when you need to set how the script returns its assembly. Replace the final top-level return statement with `return <assembly>.model();` or `return <assembly>.solvedModel(poses, options?);`. Use solvedModel for mate-authored mechanisms so FK and validation run. Returns…
solve_mates
Solve the mate graph and get part poses. Pass code/file for an atomic source-bound solve, or omit both to use the active assembly. Returns { ok, status, poses, iterations?, evaluationEvidence? } where each pose is a serialized Transform ({ translation, rotateAxis, rotateDeg }).…
review_cad
Run a deterministic mechanism-fitness review on supplied kernelCAD code or a file. It performs a full evaluation, replaces the active MCP session model on success, and clears that session if evaluation fails. The script may load referenced assets. The review validates the assemb…
design_loop
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: re…
flatten_pattern
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 {…
evaluate_sdf
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…
capture_animation
Capture a saved model animationView timeline or turntable as a downloadable MP4. Use file: "project:<slug>"; inline code, GIF and PNG-sequence output are not supported on this hosted server. Limits: 60 seconds, 60 fps, 1800 frames, 200 MiB. Turntable width/height are even and at…
render_preview
Use this when you need to LOOK at a kernelCAD model — render its script to deterministic PNG views for visual self-check (the visual half of the evaluate → render → inspect → fix loop), with NO studio or dev server required. Pass { code } (inline source) or { file } (a .kcad.ts…
resolve_assumptions
Use this when you need to confirm or override the open facts in an assumption ledger from trace_from_image (missing scale, inferred/assumed values) before committing geometry built from a reference photo. Reads the persisted `<model>.ledger.json` at `ledgerPath`, applies each re…
run_fea
Use this when you need to know whether a part will hold a load. Runs a linear-static structural study and returns evidence — peak von Mises stress (MPa), peak displacement (mm), the minimum safety factor against the material yield (taken away from the clamp-singular edges of the…
fea_summary
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;…
send_to_printer
Use this when you need to upload a .gcode file (e.g. written by export with target: "model", format: "gcode") to a real network printer and, by default, start the print. protocol: 'octoprint' (POST /api/files/local with an X-Api-Key), 'moonraker' (Klipper's POST /server/files/up…
repair_script
Use this when evaluate_script reported an error and you want the fix applied rather than described. Takes the candidates why_did_this_fail derives for a diagnostic, applies them one at a time, re-evaluates after each, and keeps the first that clears the diagnostic without introd…
sweep_tolerance
Use this when you need to know where and why a design breaks across a tolerance/dimension range, not just whether it builds at one nominal value. Declares one or more param() names with a { values: [...] } list or a { min, max, steps } range (number params are bisected; choice/s…
diff_geometry
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 repor…
drawing_to_cad
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 / extens…
mesh_to_features
Use this when you are handed an STL, OBJ or 3MF of a mostly prismatic mechanical part (plate, bracket, spacer, flange, housing block) and need an EDITABLE kernelCAD model of it rather than a faceted lib.fromSTL import. Deterministic, measured, self-verifying: it welds and checks…
execute_cookbook
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). Re…
get_selection
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…
set_selection
Use this when you need to replace the shared local Studio face/edge selection, or clear it with selection:null. The viewer highlights the pick on its next sync (300 ms). Does not edit geometry. Pass model_generation from get_selection; writes from an older generation are rejecte…
import_step
Use this when the user wants to start from their own STEP, IGES, native OCCT BREP, STL, OBJ, PLY, 3MF, glTF or GLB file (a part they designed elsewhere, a vendor model). Give exactly one source: url (a public https direct-download link), upload (a file the user attached in ChatG…
fab_pack
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…
dfm_review
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 s…
ray_pick
Use this when you need the faces a ray hits in a local Studio model, nearest first, with points, distances, and normals. Inputs are model units (mm); direction is normalized. Requires the local Studio URL and session token for the same script, reads the current model generation,…
inspect_nurbs
Evaluate supplied kernelCAD code or a file to capture an authored NURBS curve (nurbsCurve/spline3d). Returns degree, distinct knots and multiplicities, poles, weights, rational and uniformWeights flags, hasNonUnitWeights, and parameter range. Defaults to the last captured curve…
fit_plane
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.…
mesh_boolean
Use this when the user wants to union, subtract, or intersect two imported triangle mesh solids (STL, OBJ, or 3MF). Supports union, subtract (A minus B) and intersect. Pass each operand as { file } on the MCP server or { data } with base64 mesh bytes; formats are detected or may…
explode_view
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…
apply_surface_blend
Use this to author and evaluate a fillet or chamfer on a kernelCAD Shape. It inserts Shape.fillet(radius, selector, { continuity: G1 }), Shape.fillet({ start, end }, selector, { continuity }), or Shape.chamfer(distance, selector), then returns the patched source and evaluation d…
write_bom
Use this to merge a supplied handoff BOM with optional KernelCAD catalog parts, MPNs and pricing, write a local CSV, and return Sheets-ready rows. Pass exactly one of handoff, handoff_json or handoff_path. The default output is a new file under artifacts/bom; an explicit output_…
blockout_assembly
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…
price_part
Start or read the real price for making the part. Cheap. Returns status "ready" with estimate_cents and summary, or "pricing" while the makers are asked (call again in a few seconds). Creates nothing and charges nothing.
order_part
Order the part made: creates the production request and returns a pay_url for the user. Propose the manufacturing method from the user's words and the part, pass it as method with a one-line reason. The price is the real maker price; never invent or send one. Tell the user the c…
estimate_assembly_manufacturing
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, multiplies BOM quantities by batchQuantity, selects supported processes, checks live supp…
request_assembly_quote
Submit a manufacturing quote request after the user has reviewed and explicitly approved the checklist and every displayed warning. KernelCAD staff will confirm the final itemized price. This sends the request for human review and does not charge the customer or start checkout.

Details

Endpoint	`https://mcp.kernelcad.com/mcp` (Streamable HTTP)
First published	27 Oct 2026
Last updated	27 Oct 2026
Registry name	`com.kernelcad/kernelcad`

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Typical response: 167 ms
Answered: 100% of 2 checks
Last check: 13 Nov 2026

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