kernelCAD

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

• Connection: Runs in the cloud
• Transport: Streamable HTTP
• Category: Chat & email

Install

Pick the AI app you use, then copy the settings.

You need

• Runs in the cloudNothing to install; it connects over the internet

Which app do you use?

https://mcp.kernelcad.com/mcp

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

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

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

https://mcp.kernelcad.com/mcp

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These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Tool names and descriptions exactly as the server reported them on Nov 7, 2026. The maker wrote them, not us; we show them as plain text.

• review_paint_peek_latest

  Return the newest brush-painted review packet from a Studio session. After sharing a /p/ 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 + mask +

• 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). ONE VIEWER PER PROJECT PER RE

• 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/ link or a prior listing) to fetch that project's full .kcad source and metadata — then

• 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 capability

• 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'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 own

• 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 failures

• 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 man

• 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

• 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 dow

• 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 and license. Download the source with plain GET. For community slugs, returns the search fields plus

• 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

  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 sta

• 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/rem

• 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:fal

• 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 i

• 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 builds

• 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. Side-effect-free. Primitives that acc

• 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 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 `nurb

• 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, immedia

• 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 dis

• 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 eng

• project_curve

  Use this when you need to wrap a 2D closed curve onto a 3D face. Insert a ` .projectCurve({ source, face, scaleMode? })` chained call into a kernelCAD script. The `source` is the structured `{ kind: "sketchCommands", commands: [...] }` wire format the runtime API accepts. Wraps t

• add_pattern_feature

  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 diagnostic

• 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-free

• 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:'uniq

• lookup_api

  Use this when you need to list the kernelCAD script-runtime surface: global functions (box, path, selectEdges, helix, etc), Shape methods (fillet, sweep, lower, etc), Sketch methods (extrude, revolve, sweep), PathBuilder methods, EdgeQuery/FaceQuery key sets, and featureKindFaceL

• 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 interchan

• 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 co

• 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 = .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

• add_connector

  Use this when you need to add a mate connector to a part. Durably insert ` .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-fr

• 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 ` .workspace(connectorRef, { reachable, toleranceMm? })` before the final top-level return. Workspace targets are checked by solvedModel validation/review pose-envelope gates. Returns modified

• 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 .model();` or `return .solvedModel(poses, options?);`. Use solvedModel for mate-authored mechanisms so FK and validation run. Returns modified source plus

• 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 }). O

• 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 assembl

• 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: rev

• 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 { f

• 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

  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 ON

• 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 p

• 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 ` .ledger.json` at `ledgerPath`, applies each resolutio

• 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; r

• 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/upl

• 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 introdu

• 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/st

• 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 report

• 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 / extensi

• 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). Res

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 7, 2026

• ✓ Pass

  Maker matches the repo

  The registry name was verified against the domain kernelcad.com (the registry checks domain ownership)

• … Not checked yet

  Still maintained

  We have not read this repo from GitHub yet

• … Not checked yet

  Has a licence

  We have not read this repo from GitHub yet

• ✓ Pass

  Endpoint responds

  Responded in 72 ms (HTTP 200)

• – Not applicable

  Sign-in with OAuth

  No sign-in needed

• ✓ Pass

  No hidden instructions in tool descriptions

  Read 60 tool descriptions and found no hidden instructions to the AI

Compared with others in Chat & emaili

• More stars than 0% of the other 1787 servers in this category
• Published to the registry more recently than 71% of the other 1787 servers in this category
• Basic checks equal to or better than 100% of the other 1787 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Alternatives

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Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

README from the maker

npx -y kernelcad mcp

npm install --global kernelcad

curl -fsSL https://kernelcad.com/install.sh | sh

irm https://kernelcad.com/install.ps1 | iex