onshape-mcp (altendky)
Self-hosted MCP server that gives AI assistants read and write access to Onshape documents through user-owned API credentials.
What it does and how it connects
Onshape MCP connects an AI assistant to Onshape: describe what is wanted in Onshape terms, such as creating a sketch, extruding a part, or exporting an STL, and the AI handles the API calls. The README calls it a helper for people who already know Onshape, not a replacement for CAD skills, and marks it early development.
There is no public hosted MCP server or public OAuth proxy: the server runs locally or self-hosted. Authentication uses the user's own Onshape OAuth application, with user-owned client ID and secret, or API access and secret keys as an alternative. A local server can read and write files on the machine directly, including screenshots, exports, and FeatureScript.
It runs from npx with no separate install, or from a pre-built binary downloaded from the Releases page, and it works with Claude Desktop, OpenCode, or any MCP client that supports stdio transport.
Alternatives
Compare side by side- onshape-mcp (gpambrozio)
An Onshape MCP server with 93 tools for sketching, solid features, assemblies, drawings, and export, with zero-config browser sign-in.
- Jarvis Onshape MCP
A Claude Code plugin for driving real Onshape CAD with vision-based decomposition and parametric iteration.
- cloudCAD-copilot
A demo AI assistant for Onshape that detects fastener holes from real assembly geometry and batch-inserts standard parts.
- fusion360-mcp-server
An MCP server that connects AI coding agents to Fusion 360 through an in-Fusion add-in bridge.
- freecad-ai
A FreeCAD workbench with a chat interface that builds and edits 3D models from natural language through 50 structured tools and 24 LLM providers.
Recurring errors it addresses
Error Index entries this tool is built to reduce or work around.
- Drawing toolset is described as missing basic drafting capabilities and mark-up controls.Error Index
- Large-assembly handling and richer 3D communication workflows are described as limited compared with expectations.Error Index
- Onshape-exported URDF had a camera frame flipped 180 degrees and forearm roll axes 11.0 and 10.7 degrees off; editing the URDF is pointless because the export overwrites it, so a load-time correction table patches the model in memory.Error Index
- Onshape's URDF export puts a roll of -pi on the lidar joint, mirroring every scan, while the link's visual origin carries a compensating +pi so the model looks right in RViz and only the laser scan is wrong.Error Index
- A fillet fails with "both faces next to the edge must be planar" on a part the user built easily in Onshape.Error Index
Sources
Not verified
- No independent user voice found: the repository has no public issues.
- Pricing: none stated on the repo.
- A named individual builder beyond the repository owner handle altendky
Last verified November 6, 2026. Listings are informational. The evidence score measures public, verifiable evidence and is not an endorsement or a compatibility claim.