PartMode
An open-source, local-first 3D parametric CAD application that runs in the browser, built on OpenCascade WebAssembly, for both human designers and permissioned AI agents editing the same document.
PartMode is browser-based mechanical CAD built on OpenCascade WebAssembly, the replicad library and three.js, combining constrained sketches, an editable feature history, exact boundary-representation geometry evaluation, assemblies, drawings and standard exchange formats in one application that needs no separate desktop CAD installation. It can be used anonymously in the browser, with hosted agent connectivity and document storage as separate, explicit opt-in choices.
Its design principle is that human and agent changes go through the same canonical document model and geometry kernel, rather than the agent working through a parallel, opaque automation path: a person can revise a project through the CAD interface, and a browser-approved agent can edit the same open project through typed, permissioned operations against that document's schema.
Supported modeling features include dimensions and expressions, direct edits, configurations, patterns, holes, threads and sheet-metal tools, reusable part definitions with mates and exploded views for assemblies, exact hidden-line drawing views that can carry dimensions and tolerances, and interchange through STEP import and export plus STL, AMF and 3MF mesh exports. It is free to use, inspect, modify and self-host under the GNU AGPL v3 license.