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Kerf

vulos.org

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Spec score 8.6 #3 of 21 in Jewelry Design Software

What it is

Kerf is a free, open-source CAD workspace that runs on the user's own machine and supports work across 37 engineering domains. Users can describe design changes in plain language or use the Python kerf-sdk and JSON-RPC API. Mechanical design tools include constraint-based sketching, parametric feature history, validated B-rep geometry, drawings, and persistent face references. The workspace also includes FEM analysis, topology optimization, SPICE and RF analysis, CAM toolpaths, and G-code output. Listed outputs include STEP, STL, 3MF, IFC4, Gerber, PDF, DXF, BOM CSV, Touchstone, GDS-II, and firmware binaries. The site describes workflows for mechanical and electronics engineers, BIM architects, jewelry designers, and other engineering users. Kerf runs locally without accounts and keeps Git history for file revisions. Workshop content can be used offline once pinned. Installation options include source or Docker, with release archives listed for macOS arm64, macOS x64, and Linux x64; source installation requires Python 3.11 or later. The chat workflow can use a bring-your-own LLM; no bundled model or paid hosted plan is listed.

Spec sheet

What it does
Kerf is a locally run CAD system combining parametric modeling, drawings, simulation, CAM, electronics, BIM and manufacturing workflows.Read 14 Oct 2026 · vulos.org
Deployment
Kerf can be installed from source or Docker, and the site lists release archives for macOS arm64, macOS x64, and Linux x64.Read 29 Sep 2026 · vulos.org
API
Kerf exposes a JSON-RPC interface at /v1/rpc for automation.Read 14 Oct 2026 · vulos.org
License
Kerf's own source code is released under the MIT license.Read 14 Oct 2026 · github.com
Maker
Kerf is part of the Vulos open-source software organization.Read 14 Oct 2026 · github.com
BIM and AEC
BIM features include parametric building elements, MEP families, schedules, IFC round-trip, civil corridors and structural design.Read 14 Oct 2026 · github.com
CAD features
Mechanical design includes a constraint-based sketcher, parametric feature history, validated B-rep geometry, drawings, and persistent face references.Read 29 Sep 2026 · vulos.org
Chat and scripting
Users can describe design changes in plain language or script the same tool surface with the Python kerf-sdk and JSON-RPC API.Read 29 Sep 2026 · vulos.org
Chat editing
An LLM can read and edit project source files through a registry of more than 3,000 purpose-built tools, with changes recorded as reviewable diffs.Read 14 Oct 2026 · github.com
Data ownership
Project revisions and local Git history are stored on the operator's node, and an unconfigured installation does not open network sockets.Read 14 Oct 2026 · github.com
Desktop builds
The 0.1.9 release lists one-file desktop binaries for macOS Apple Silicon, Windows x64 and Linux x64.Read 14 Oct 2026 · github.com
Documentation
The documentation site contains getting-started, installation, configuration, architecture, file-format, domain, API, SDK, plugin and deployment sections.Read 14 Oct 2026 · vulos.org
Download platforms
Release assets include macOS Apple Silicon, macOS Intel, Linux x64 and source archives.Read 14 Oct 2026 · github.com
Drawings
Kerf provides multi-sheet technical drawings with GD&T callouts and drawing export.Read 14 Oct 2026 · github.com
Electronics
Electronics functions cover tscircuit JSX, schematic and PCB work, ngspice simulation, RF analysis, autorouting, signal integrity and power integrity.Read 14 Oct 2026 · github.com
Engineering domains
The product advertises 37 engineering domains, including mechanical, electronics, architecture, jewelry, aerospace, marine and textiles.Read 14 Oct 2026 · vulos.org
Feature comparison limit
Kerf's parity matrix says its comparisons measure only how much of Kerf's listed capability set competitors cover, not whether Kerf replaces those products.Read 14 Oct 2026 · vulos.org
File outputs
Listed outputs include STEP, STL, 3MF, IFC4, Gerber, G-code, PDF, DXF, BOM CSV, Touchstone, GDS-II, and firmware binaries.Read 29 Sep 2026 · vulos.org
Geometry kernels
Kerf supports JSCAD, OpenCascade B-rep, analytic NURBS, Catmull-Clark subdivision and SDF/F-rep geometry kernels.Read 14 Oct 2026 · github.com
Integrations and kernels
The site lists JSCAD, OpenCascade, tscircuit, planegcs, FEniCSx, OpenCAMlib, IfcOpenShell, FreeRouting, and KiCad among its open kernels and tools.Read 29 Sep 2026 · vulos.org
Limit: desktop feature coverage
The desktop binaries are lean builds and omit pythonOCC-based B-rep modeling and FEniCSx/dolfinx FEM, which require conda-based installation or Docker.Read 14 Oct 2026 · github.com
Limit: development dependency resolution
The repository states that uv sync currently fails because workspace extras require conda-forge-only packages; its development install helper is the workaround.Read 14 Oct 2026 · github.com
Limit: geometry implementation
The geometry roadmap says the pure-Python B-rep model is not yet wired into production surfacing operations, which still delegate solids and booleans to OCCT.Read 14 Oct 2026 · github.com
Limit: unfinished tests
The repository describes kernel and engineering-domain test tiers as having known failures, with domain tests marked experimental and red.Read 14 Oct 2026 · github.com
Limit: Workshop browsing
Offline browsing of followed Workshop feeds is not implemented; pinned part bytes remain available locally but the catalog requires a reachable feed.Read 14 Oct 2026 · github.com
Local data and history
Kerf keeps local Git history, with revisions recorded for file edits; the site says the app runs locally without accounts.Read 29 Sep 2026 · vulos.org
Local installation
Standalone installs use an embedded SQLite database, while Postgres is optional for shared deployments.Read 14 Oct 2026 · github.com
Maker location
The Kerf site identifies the project as made in South Africa.Read 14 Oct 2026 · vulos.org
Manufacturing
Manufacturing tools include 2.5D, 3D, lathe and wire-EDM CAM, Fanuc posts, sheet metal, mold splitting, nesting, GD&T and CuraEngine slicing.Read 14 Oct 2026 · github.com
Notable limit
The site says Kerf’s chat workflow can use a bring-your-own LLM; it does not list a bundled model or paid hosted plan.Read 29 Sep 2026 · vulos.org
Parametric modeling
Feature operations include pads, pockets, revolves, fillets, chamfers, shells, holes, patterns, sweeps and lofts.Read 14 Oct 2026 · github.com
Python SDK
The product provides a Python package named kerf-sdk for scripting and parameter sweeps.Read 14 Oct 2026 · vulos.org
Release news
Version 0.1.9 was released on 2026-08-11 and corrected an npm software-bill-of-materials generation defect.Read 14 Oct 2026 · github.com
Repository activity
The public GitHub repository shows 16 stars, 5 forks and more than 4,000 commits.Read 14 Oct 2026 · github.com
Requirements
The source installation instructions specify Python 3.11 or later; the main page says its embedded SQLite setup needs no database server.Read 29 Sep 2026 · vulos.org
Security and provenance
Releases provide SHA256SUMS manifests and sigstore build-provenance attestations for downloadable artifacts.Read 14 Oct 2026 · github.com
Security and sharing
The Workshop uses an open protocol for signed, content-addressed objects; the site says it needs no account or central server and supports offline use once content is pinned.Read 29 Sep 2026 · vulos.org
Simulation
The system includes FEM, CFD, topology optimization, multibody motion, optics and one-dimensional system simulation capabilities.Read 14 Oct 2026 · github.com
Simulation and manufacturing
The workspace includes FEM analysis, topology optimization, SPICE simulation, RF analysis, CAM toolpaths, and G-code output.Read 29 Sep 2026 · vulos.org
Sketching
Its sketcher uses the planegcs constraint solver and feeds a feature-based OpenCascade solid model.Read 14 Oct 2026 · vulos.org
System requirements
Source development requires Python 3.11 or newer and Node 22 or newer.Read 14 Oct 2026 · github.com
Third-party licenses
The distribution links libraries under LGPL-2.1, LGPL-2.0+ and MPL-2.0 licenses, which are listed in its third-party license file.Read 14 Oct 2026 · github.com
Who it is for
The site describes workflows for mechanical and electronics engineers, BIM architects, jewelry designers, and users in other engineering disciplines.Read 29 Sep 2026 · vulos.org
Workshop
The optional Workshop publishes signed, content-addressed parts over the DMTAP-PUB protocol without a central catalog or required account.Read 14 Oct 2026 · github.com

Plans and prices

Free Free Free; MIT licensed Runs locally · no accounts · no billing Read 29 Sep 2026 · vulos.org
Kerf Free complete CAD workspace · MIT licensed · no account · no cloud billing Read 14 Oct 2026 · vulos.org

Every Kerf plan and price →

Strong points and limits

Strong points

  • Runs locally without accounts
  • Supports scripting through Python and JSON-RPC
  • Includes simulation and manufacturing tools
  • Workshop content can work offline once pinned

Limits

  • Source installation requires Python 3.11 or later
  • Chat workflow can require a bring-your-own LLM
  • No bundled model or paid hosted plan is listed

Who it suits

Kerf suits engineers and designers who want local CAD workflows, including mechanical and electronics engineers, BIM architects, and jewelry designers. It may also suit users comfortable installing software from source or Docker and supplying their own LLM for chat.

Kerf in depth

Read the full write-up

Overview

Kerf is a local CAD workspace for people who want to move between engineering design, analysis, and fabrication rather than hand work off between separate tools. Its strongest fit is a technically minded designer comfortable with source-based installation and supplying an LLM for chat; readers seeking a turnkey hosted assistant should look elsewhere.

The workspace spans 37 engineering domains, with workflows for mechanical and electronics engineers, BIM architects, jewelry designers, and others. Users can describe changes in plain language or script the same tool surface through the Python kerf-sdk or JSON-RPC API. Keeping data and Git revision history local is a meaningful advantage for users who want control over files and workflow, though it also puts installation and model choice in their hands.

Key features

Modeling, simulation, and fabrication

Mechanical tools include a constraint-based sketcher, parametric feature history, validated B-rep geometry, drawings, and persistent face references. Jewelry workflows add ring sizing, stone setting, photorealistic rendering, and manufacturing export. That combination makes Kerf unusually broad for a free workspace, but users wanting a narrowly focused design package may have little use for its wider engineering scope.

Kerf also brings FEM analysis, topology optimization, SPICE simulation, RF analysis, CAM toolpaths, and G-code output into the workspace. Export formats include STEP, STL, 3MF, IFC4, Gerber, PDF, DXF, BOM CSV, Touchstone, GDS-II, firmware binaries, and G-code. The range can support work from model creation through production handoff, though it also reflects the demands of a technically diverse toolset.

Code, integrations, and sharing

For repeatable or automated workflows, the Python SDK and JSON-RPC API expose the same tools used through chat. Kerf lists open kernels and tools including JSCAD, OpenCascade, tscircuit, FEniCSx, OpenCAMlib, IfcOpenShell, FreeRouting, and KiCad. Its Workshop uses signed, content-addressed objects over an open protocol; it needs no account or central server, and pinned content can be used offline.

Files and their revision history stay local, and the app runs without accounts. Chat is the main caveat: users bring their own LLM, with no bundled model or paid hosted plan. That suits people who already have a model workflow, but makes Kerf a less direct choice for anyone expecting chat to work out of the box.

Pricing

Kerf is free: its Free plan costs nothing, is MIT licensed, runs locally, and requires no account or billing. There is no paid tier described; the chat workflow still requires users to provide their own LLM. For a free tool with parametric modeling, jewelry tools, rendering, and manufacturing export, the plan is generous, but it does not remove the setup and model-sourcing responsibilities.

Platforms

Kerf is available for Linux and macOS, with API, web, and self-hosted platforms also listed. Installation is supported from source or Docker; release archives are listed for macOS arm64, macOS x64, and Linux x64. Source installation requires Python 3.11 or later, while the embedded SQLite setup needs no database server. This suits users comfortable managing a local development-style installation better than those looking for a conventional one-click hosted service.

Who it's for

Kerf is a strong candidate for engineers and designers who want local control, scripting access, and one workspace spanning CAD, simulation, and manufacturing. Its listed jewelry features make it relevant to jewelry designers as well. It is a poor fit for people who need a bundled conversational model or prefer a hosted, account-based workflow.

Pros and cons

Pro: Free, MIT-licensed access to parametric CAD, jewelry tools, simulation, and manufacturing output makes the scope unusually broad without a subscription.

Pro: Local files and Git history, plus account-free Workshop sharing, keep data and revisions under the user's control.

Pro: Python and JSON-RPC access provide a route to automate the same tools available through chat.

Con: Chat requires a user-supplied LLM, so conversational design is not ready to use by itself.

Con: Source installation requires Python 3.11 or later; that is a real setup hurdle for users who want a conventional desktop installer.

Alternatives

For jewelry-focused options, browse Jewelry Design Software. Rhino 3D is worth considering if you prefer paid software with a permanent-license option and a free plan and trial. Diatech Studio may suit a mobile-first user: it lists Android and iOS alongside web and self-hosted access, with a free plan that includes AI features and 25 images.

3Design CAD is another paid, jewelry-oriented option for users who want a product with a free trial. Pencil may be a better fit for web-based jewelry design, but its free plan limits users to three designs and provides no AI credits. ZBrush is an alternative for users interested in sculpting, with a free iPad plan that includes 28 brushes.

CounterSketch is a paid option with a free trial for users who value tech support, an online academy, and library updates. Drakon may suit Windows or web users who prefer buying Copilot credits, with listed one-time options of 20.00 EUR for 5,000 credits and 50.00 EUR for 12,500. Carveco is a Windows-only paid alternative with a 30-day free trial for new customers.

Verdict

Choose Kerf if you want a free, local engineering workspace that connects parametric design, analysis, scripting, and manufacturing output. Its breadth and local history are compelling for users comfortable installing it and bringing their own LLM. If you need ready-to-use chat or a conventional hosted workflow, choose another tool.

Verdict

Kerf spans design, simulation, and manufacturing workflows while keeping files and history local. Users should note the source-install requirement and the need to bring their own LLM for chat.

Where Specifiction places it

Alternatives to KerfAll alternatives →