Kerf

Kerf is a free, open-source CAD workspace designed to run on a user's own machine and support work across 37 engineering domains. Design changes can be described in plain language or scripted through the Python kerf-sdk and JSON-RPC API. Mechanical 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 exports cover STEP, STL, 3MF, IFC4, Gerber, PDF, DXF, BOM CSV, Touchstone, GDS-II, and firmware binaries. Kerf describes workflows for mechanical and electronics engineers, BIM architects, jewelry designers, and other engineering users. It runs locally without accounts, keeps Git history for file revisions, and supports offline use once Workshop content is pinned. Installation is available from source or Docker, with release archives for macOS arm64, macOS x64, and Linux x64. Source installation requires Python 3.11 or later. Chat can use a bring-your-own LLM; no bundled model or paid hosted plan is listed.

Kerf brings CAD, simulation, and manufacturing workflows into a locally run workspace with chat and scripting options. Users should account for the bring-your-own LLM requirement for chat and the stated source-installation requirement.

Kerf suits engineering users who want local CAD workflows, including mechanical and electronics engineers, BIM architects, and jewelry designers. It may also suit users comfortable scripting with Python or an API.

Overview

Kerf is an open-source CAD workspace for people who want design, analysis, and manufacturing tools in one local environment. It is especially suited to engineers and jewelry designers comfortable supplying their own LLM for chat; the range is compelling, but it is not a turnkey hosted AI service.

Users can describe design changes in plain language or work through the same tool surface with Python or JSON-RPC. That flexibility makes Kerf relevant both to conversational workflows and to scripted automation, while local Git history records file revisions on the machine.

Key features

Modeling and jewelry tools

Mechanical design includes a constraint-based sketcher, parametric feature history, validated B-rep geometry, drawings, and persistent face references. Parametric modeling, ring sizing, stone setting, photorealistic rendering, and manufacturing export extend its appeal to jewelry work. This breadth is useful for designers who want one workspace across design and production, though users seeking only a narrow specialty tool may not need its wider engineering scope.

Analysis and manufacturing

Kerf brings together FEM analysis, topology optimization, SPICE simulation, RF analysis, CAM toolpaths, and G-code output. Its listed exports include STEP, STL, 3MF, IFC4, Gerber, PDF, DXF, BOM CSV, Touchstone, GDS-II, firmware binaries, and G-code. That reach can support varied engineering handoffs; the trade-off is that this is a broad toolset rather than a single-purpose workflow.

Local work and sharing

The app runs locally without accounts and uses an embedded SQLite setup that needs no database server. Workshop sharing uses signed, content-addressed objects over an open protocol, with no central server or account requirement and offline use once content is pinned. That model favors users who value local control, but chat still requires a bring-your-own LLM.

Kerf lists JSCAD, OpenCascade, tscircuit, planegcs, FEniCSx, OpenCAMlib, IfcOpenShell, FreeRouting, and KiCad among its open kernels and tools. Installation options include source or Docker, with release archives for macOS arm64, macOS x64, and Linux x64; source installation instructions require Python 3.11 or later.

Pricing

Kerf's Free plan costs nothing, billed Free. It is MIT licensed, runs locally, and has no accounts or billing. That makes it an unusually direct option for individuals who can manage local installation and provide their own LLM for chat. There is no paid hosted tier described in its offering, so users wanting a bundled model or managed service should look elsewhere.

Platforms

Kerf lists API, Linux, macOS, self-hosted, and web platforms, and describes the workspace as hybrid. The release archives cover macOS arm64, macOS x64, and Linux x64; source installation requires Python 3.11 or later.

Who it's for

Kerf suits mechanical and electronics engineers, BIM architects, jewelry designers, and others in engineering disciplines who want CAD alongside simulation or manufacturing workflows. Its local execution and scripting options will matter most to people comfortable configuring software and integrating an LLM. It is a weaker fit for anyone seeking a ready-to-use hosted chat product or a focused package without broader engineering tools.

Pros and cons

• Pro: CAD, simulation, and manufacturing tools share one workspace, reducing the need to split those workflows across separate applications.
• Pro: Local execution, Git-based revision history, and account-free Workshop sharing suit users who want control over their files and collaboration protocol.
• Pro: Python and JSON-RPC access provide options beyond plain-language design changes.
• Con: Chat requires a user-supplied LLM, so it is not a complete out-of-the-box AI workflow.
• Con: Source installation requires Python 3.11 or later, which adds setup work for users who do not use a release archive or Docker.

Alternatives

For a jewelry-focused comparison, start with the Jewelry Design Software category. Pencil is a better fit for someone who wants a web or API option and a free tier capped at three designs, with STL downloads and file uploads. Rhino 3D is a paid Windows and macOS alternative with a free trial for readers considering a commercial license.

ZBrush is another freemium option for Windows and macOS. Drakon is a paid web and Windows option with a free trial. Jewelry CAD Dream is a paid Windows alternative without a free plan or trial. Autodesk Fusion offers a free plan and macOS, web, and Windows support for readers comparing a broader CAD/CAM option. CounterSketch is a paid macOS and Windows alternative with a free trial. FormaNova AI Jewelry CAD is a paid web alternative.

Verdict

Choose Kerf if you want open-source CAD with local history, scripting, and a notably broad mix of analysis and manufacturing tools, especially for engineering or jewelry workflows. Look elsewhere if you need chat with a bundled model or prefer a hosted, managed product.