SolidCraft
Open-source parametric 3D CAD application in pure Rust with a built-in MCP server so AI agents can model, measure, and inspect parts headlessly.
What it does and how it connects
SolidCraft is an open-source parametric 3D CAD application built in pure Rust. Users sketch, constrain, and build solids with a parametric feature timeline, so changing a dimension rebuilds the model. It runs as a desktop app, in the browser, or headlessly, with downloads for Windows, macOS, and Linux, plus a Snap package.
AI agents drive it through a built-in MCP server: solidcraft-cli mcp speaks the Model Context Protocol, and the same commands run across the desktop app, browser app, headless CLI, and MCP server. The README states the application is early but usable for simple parts, with 75 of 76 public reference parts matching their analytic or FreeCAD-computed volume, area, centre of mass, and bounding box.
The demo in the README builds a Raspberry Pi 4 case from an empty design: a dimensioned sketch, extrude, fillets, shell, standoffs patterned on the board's mounting holes, port cut-outs, vent slots, engraved text, and a PETG material with its mass in Properties, then a height change in Parameters that rebuilds the whole part.
The repository moved from bherbruck/solidcraft to tangency-labs/solidcraft; stats are for the current location.
What engineers report
Today SolidCraft can't open them, so a board from any ECAD tool can't be used to design an enclosure around it, and a future CAM workspace has no board data to mill.
2026-11-07Read the original
Alternatives
Compare side by side- Serpentine3D
Serpentine3D is a Rhino-style NURBS surface modeller on OpenCASCADE, while SolidCraft is a parametric solid CAD application in Rust.
- agentcad
agentcad is a CLI and MCP server over build123d scripts, while SolidCraft is a full CAD application with a built-in MCP server.
- CAD-MCP
CAD-MCP drives AutoCAD, GstarCAD, and ZWCAD through an MCP server, while SolidCraft is a standalone CAD application with its own MCP server.
- CADAgent
CADAgent is a Fusion 360 add-in driven by a self-hosted backend, while SolidCraft is a standalone CAD application with a built-in MCP server.
- MecAgent
MecAgent is a commercial AI agent for CAD, while SolidCraft is a free open-source CAD application with a built-in MCP server.
Recurring errors it addresses
Error Index entries this tool is built to reduce or work around.
- A STEP export from SolidCraft lost the side faces on 3 of 4 tapered legs when opened in other CAD tools, leaving only end discs. SolidCraft read its own file back fine; the fault was which ring of the cone face the loop started on, which other readers depend on.Error Index
- After a shell on a tapered, filleted box, four inner corner fillet edges miss their surface by up to 0.0198 mm. SolidCraft shows the body and re-imports it without complaint; FreeCAD 1.1.4, used as an outside reader, flags the four faces as invalid.Error Index
- Booleans on lofted B-spline bodies are 1 to 2 orders of magnitude slower than on prismatic bodies, and a join between bodies sharing faces of the same loft fails after 5 min 11 s with 'no result', while the same part builds fine in FreeCAD/OCCT.Error Index
- An RFC to refuse a Join when the new material doesn't touch the body, citing five earlier reports of bodies ending up in pieces without anyone meaning it, including one where a Combine Intersect silently removed a whole body made of seven separate spheres.Error Index
Sources
Not verified
- Pricing: none stated on the repo as read
- A named individual builder beyond the tangency-labs organization
Last verified November 6, 2026. Listings are informational. The evidence score measures public, verifiable evidence and is not an endorsement or a compatibility claim.