PartMode is free and open-source, browser-based parametric CAD built for people and agents. It combines OpenCascade WebAssembly, replicad, and three.js with editable parts, structured assemblies, exact B-rep evaluation, drawings, and standard interchange formats.
- Free and open source — use, inspect, modify, and self-host PartMode under the GNU AGPL v3 license.
- Browser-based — create and edit exact CAD models through a local-first web interface, with no desktop CAD installation required.
- Agent-first CAD — permissioned agents use typed operations against the same editable documents and exact geometry evidence as the human interface. Agent-first does not mean agent-only: people and agents can build, inspect, revise, and export the same models.
Try PartMode · Read the in-product help
- Parametric sketches and feature history
- Multiple exact solid bodies and reusable part definitions
- Assembly occurrences, mates, exploded views, and sections
- Configurations, inspection, measurements, and mass properties
- STEP import/export plus STL, AMF, 3MF, SVG, DXF, and PDF outputs
- Browser-approved agent sessions and opt-in server-headless projects
- Regression tests for document, topology, B-rep, export, and visible UI behavior
PartMode is engineering software, not a certification authority. Validate dimensions, tolerances, material choices, and released manufacturing data for your application.
PartMode requires Node.js 22.13 or newer.
npm ci
npm run build
npm startThe server listens on http://127.0.0.1:4401 by default. Browser-local CAD does
not require an account or external service.
npm run ci:gateThe focused gate type-checks and builds the release, verifies the static and
runtime manifests, and exercises the local HTTP, account, identity, MCP, cloud,
and entrypoint contracts. The larger CAD and browser suites remain available as
individual smoke:* scripts and through npm run release:gate.
This repository contains the standalone PartMode product source, public technical documentation, fixtures, and tests. Production credentials, private operations, deployment configuration, internal handovers, and release records are intentionally outside this repository.
The BOMWiki organization is the administrative home of this repository; PartMode does not depend on BOMWiki applications, services, databases, ports, or deployment infrastructure.
See CONTRIBUTING.md before proposing a change and SECURITY.md for vulnerability reports. Third-party components and their licenses are listed in THIRD_PARTY_NOTICES.md.
PartMode is licensed under the GNU Affero General Public License v3.0 only. Copyright © 2026 Sphinx.