Kerf

Overview

Kerf is a local CAD workspace for engineers and designers who want to move between modeling, analysis, and manufacturing rather than hand work off between separate tools. Its breadth is its clearest advantage, while the chat workflow is a poor fit for anyone expecting an AI model to come with the software.

Mechanical and electronics engineers, BIM architects, and jewelry designers are among the audiences its workflows address. Because users can also script the same tool surface, Kerf is especially compelling for technically minded people who value automation and local control over a narrow, turnkey application.

Key features

Modeling through chat or code

Users can describe design changes in plain language or work through the Python kerf-sdk and JSON-RPC API. Sharing one tool surface across these approaches makes Kerf useful for combining interactive design with scripted workflows. But chat depends on a bring-your-own LLM: without a model supplied by the user, it is not a ready-to-go conversational assistant.

CAD, simulation, and production

Mechanical design includes a constraint-based sketcher, parametric feature history, validated B-rep geometry, drawings, and persistent face references. Jewelry workflows include ring sizing, stone setting, photorealistic rendering, and manufacturing export. This makes Kerf relevant to more than general mechanical modeling, though its broad engineering scope may be excessive for someone seeking only a focused jewelry-design package.

Analysis tools span FEM, topology optimization, SPICE simulation, and RF analysis, while manufacturing workflows include CAM toolpaths and G-code output. Listed exports include STEP, STL, 3MF, IFC4, Gerber, PDF, DXF, BOM CSV, Touchstone, GDS-II, firmware binaries, and G-code. That range supports varied disciplines, but prospective users should match their specific workflow to the formats and tools Kerf names.

Local history and sharing

Kerf records file edits in local Git history and runs without accounts. Its Workshop uses an open protocol for signed, content-addressed objects; the site says no central server is needed and pinned content remains usable offline. For people who want local data and account-free sharing, that is a meaningful distinction. The workspace also uses embedded SQLite without a database server.

The listed open kernels and tools include JSCAD, OpenCascade, tscircuit, planegcs, FEniCSx, OpenCAMlib, IfcOpenShell, FreeRouting, and KiCad. Kerf therefore brings together a wide technical surface, rather than presenting itself as a single-purpose CAD application.

Pricing

Free — free (billed Free; MIT licensed). The plan runs locally with no accounts and no billing, making Kerf a practical choice for individuals or teams evaluating an open-source workspace without a subscription commitment. Its cost advantage does not remove the need to supply an LLM for chat; there is no bundled model or paid hosted plan described.

Platforms

Kerf is listed for Linux, macOS, web, API, and self-hosted use. It can be installed from source or Docker, and release archives are listed for macOS arm64, macOS x64, and Linux x64. Source installation requires Python 3.11 or later, so that route is best for users comfortable with the stated runtime requirement.

Who it's for

Kerf is a strong fit for engineers and designers who want one local workspace spanning CAD, simulation, and manufacturing, particularly those willing to use code or provide their own LLM. Its jewelry tools also make it worth considering for designers who need ring sizing or stone setting alongside broader engineering capabilities. It is less suitable for people who want hosted AI chat ready to use or a specialized product that confines itself to one discipline.

Pros and cons

• Pros: A broad combination of parametric CAD, simulation, and manufacturing tools can keep more of an engineering workflow in one workspace.
• Pros: Local operation, file-edit Git history, and account-free Workshop sharing suit users who prioritize control over their data and offline access to pinned content.
• Pros: Python and JSON-RPC access give technically minded users an alternative to describing changes in chat.
• Cons: Chat requires a user-provided LLM, so the conversational workflow is not turnkey.
• Cons: Source installation requires Python 3.11 or later, a consideration for users choosing that setup route.
• Cons: Its coverage of 37 engineering domains may be more scope than users seeking only a focused design tool need.

Alternatives

For a dedicated jewelry-design comparison, browse Jewelry Design Software.

Rhino 3D is a paid option with a free plan and trial, available for Windows and macOS; its Commercial Rhino 8 single concurrent user plan is a permanent license at $995 a month and covers one concurrent user. Choose it if that licensing arrangement and desktop platform fit better than Kerf's local open-source approach.

Autodesk Fusion is freemium for macOS, web, and Windows. Its $57 a month plan, billed annually, includes integrated CAD/CAM, real-time team collaboration, PCB design and electromechanical integration, and drawing automation; it may suit readers who prioritize those named capabilities.

Pencil is a freemium API and web option. Its free plan lasts forever, provides 0 AI credits, limits users to 3 designs, and supports STL downloads and file uploads; Professional costs $39 a month. It is a narrower alternative to consider for a web-oriented jewelry workflow.

ZBrush is a freemium Windows and macOS option. Its iPad free plan includes 28 brushes, while the subscription provides multi-resolution mesh editing; readers focused on that named capability may prefer it.

Diatech Studio is a freemium web alternative.

3Design CAD is a paid option for Windows and macOS.

CounterSketch is a paid Windows and macOS option with a free trial. Its membership costs $349 a year; international price shown as $549/year, and includes tech support, an Online Academy, monthly library updates, and quarterly updates. It may suit readers who value those membership inclusions.

Drakon is a paid web and Windows option with one-time Copilot credit packs, including 5,000 credits for 20.00 EUR and 12,500 credits for 50.00 EUR.

Verdict

Choose Kerf if you want a free, local, open-source workspace that connects CAD with simulation and manufacturing, and are comfortable supplying your own LLM for chat. Look elsewhere if a bundled conversational model or a more focused, ready-made design package matters more than breadth and local control.