solidworks-mcp

An MCP server that lets agents drive SolidWorks 2022 directly, sketching features (extrude/cut/revolve/fillet/chamfer/shell/patterns), driving dimensions and equations, exporting, and inspecting mass properties.

This only works on Windows, and only on the machine where SolidWorks 2022 is actually installed. SolidWorks automation goes through Windows COM.

How it works

SolidWorks exposes its entire API over COM natively. So this server is the whole bridge, no separate addon to install inside SolidWorks. When a tool calls sw_connect, the server attaches to a running SolidWorks or launches one if none is open using pywin32.

SolidWorks API enum constants (like "blind" vs "through all" for an extrude) aren't hard-coded, they're pulled live from your installed SolidWorks type library via win32com.gencache, so they're guaranteed to be correct for your install rather than a guess.

Related MCP server: solidworks-mcp

Setup

Windows only. Install SolidWorks and Python 3.10+ (Python 3.11–3.13 are reasonable choices), then run setup.bat from the repository folder. No Python dependencies are installed globally: the installer creates/reuses .venv, installs requirements.txt, and verifies the MCP and COM imports before registering clients.

The installer detects compatible Python interpreters (including the Windows Python launcher), reports incompatible versions, detects registered SolidWorks versions, and configures detected MCP clients. Supported clients: Claude Desktop, Claude Code CLI, OpenAI Codex CLI, Cursor, OpenCode, Windsurf, Gemini CLI and VS Code (GitHub Copilot MCP). It registers solidworks for modern SolidWorks and/or solidworks2011 for SolidWorks 2011. Multiple detected SolidWorks versions can be registered together.

Existing JSON settings are retained and backed up before changes. If an existing JSONC config has comments or trailing commas that PowerShell cannot safely parse, setup skips that config instead of overwriting it. Codex and Claude Code are configured using their own CLI commands; they must be on PATH for automatic registration. A Codex desktop installation without the CLI is detected but cannot be configured automatically by this installer.

PowerShell options (run from the repository folder):

.\setup.ps1                        # auto-detect versions and clients
.\setup.ps1 -Server Modern         # modern SolidWorks only
.\setup.ps1 -Server 2011           # SolidWorks 2011 only
.\setup.ps1 -Server Both           # register separate modern/2011 servers
.\setup.ps1 -Clients cursor        # configure Cursor explicitly
.\setup.ps1 -AllClients            # attempt every supported client (including absent ones)

setup.bat passes arguments through to the PowerShell installer. The MCP command uses the absolute path to this repository's .venv\Scripts\python.exe. Keep the repository in place afterward; moving it requires rerunning setup. Restart the configured client and approve/enable its MCP server if prompted.

Manual alternative: create a Python 3.10+ virtual environment, install requirements.txt there, and configure your client with the environment's python.exe and this repository's root server.py (or sw2011\server.py).

Example workflow

"Make a 60x40x10mm plate with a 5mm hole in the middle and round the top edges" would roughly become:

1. sw_new_part

2. sw_new_sketch (Front Plane)

3. sw_sketch_rectangle (centered, 60x40)

4. sw_sketch_add_dimension on each side you want fixed (or drive it via sw_add_equation later)

5. sw_sketch_exit → returns e.g. "Sketch1"

6. sw_feature_extrude_boss (sketch_name="Sketch1", depth_mm=10)

7. sw_new_sketch on the top face, sw_sketch_circle (r=2.5), sw_sketch_exit

8. sw_feature_extrude_cut (through_all=True)

9. sw_feature_fillet (all_edges=True, radius_mm=1) — or pass specific edge_points_mm if you only want certain edges

10. sw_export_file to a .step or .sldprt path

sw_list_dimensions / sw_set_dimension let you go back and change any value afterward, that's the point of doing this through the API rather than just exporting a fixed mesh from a converter script.

Other things worth knowing:

• Units: every tool takes millimeters (or degrees for angles) and converts internally, the raw SolidWorks API always works in meters/radians regardless of your document's display units.

• sw_export_file uses the simplest SaveAs overload. If it errors on your install, IModelDocExtension.SaveAs3 is the modern replacement (needs an AdvancedSaveAsOptions object), the docstring links straight to the API help page.

• Edge/face selection (fillet, chamfer, shell) works by passing an approximate XYZ point near the edge/face rather than a name, SolidWorks doesn't give edges friendly names the way it does planes. You'll generally want sw_screenshot or your own visual inspection to get coordinates, or use all_edges=True on fillet to just round everything.

• Single-instance COM: this server assumes one SolidWorks session and processes tool calls one at a time, that matches how you'd drive the UI yourself, and avoids COM's threading headaches.

Extending it

Tool modules live in tools/, one file per rough category (sketching, features, documents, parameters, inspection). Each exposes a register(mcp) function. connection.py's get_const(name) is the way to pull any SolidWorks enum by name, add new tools there rather than hard-coding integers. The full API reference is at https://help.solidworks.com/2022/english/api/sldworksapi/welcome.htm.