solidworks-mcp

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An MCP server that lets Claude — or any MCP client that speaks Streamable HTTP — drive SolidWorks 2021 to create engineering drawings over your LAN, through the pywin32 COM API.

Open a part, generate first-angle standard views, add dimensions and balloons, insert a BOM table, then export to PDF — all from a Claude conversation.

Features

21 tools in 5 categories:

Category	Tools
File operations (3)	open / close / list documents
Drawing views (6)	create drawing from template, standard views, first-angle aligned 3-view, section view, detail view, custom-orientation view
Annotation (6)	import model dimensions, probe edges, add dimensions (linear / diameter / radius / angle), auto reference dimensions, balloons, BOM table
Export (4)	capture drawing (JPEG), capture model views, save as PDF, save drawing
Assembly analysis (2)	read mates, read feature tree

See the full tool reference below.

Architecture

Claude Code ◄── Streamable HTTP ──► src/server.py (FastMCP)
                                         │
                                    async tool handlers
                                         │
                                    sw.execute(func)  ← asyncio + Future
                                         │
                                    COM Worker Thread (STA, singleton)
                                         │
                                    pywin32 COM → SolidWorks 2021

SolidWorks COM must be driven from a single STA thread. All tool handlers are async and dispatch their COM callables onto a dedicated worker thread, bridged back with concurrent.futures.Future.

Requirements

• Windows 10/11 host with SolidWorks 2021 installed
• Python 3.10+
• An MCP client that supports Streamable HTTP (e.g. Claude Code, Codex CLI, Gemini CLI, Cursor — see Compatible MCP clients) on the same trusted LAN
• Optional: a drawing template (.drwdot) and an SMB shared folder for large screenshots / PDFs

Only SolidWorks 2021 has been tested. Other versions may work since the COM API is largely stable, but no guarantees.

Quick Start

1. Install (on the SolidWorks host)

git clone https://github.com/haunchen/solidworks-mcp.git
cd solidworks-mcp
python -m venv .venv
.venv\Scripts\pip install -r requirements.txt

Offline installation (host without internet access)

On a machine with internet access:

pip download -d ./wheels -r requirements.txt

Copy the repo (including wheels/) to the SolidWorks host, then:

.venv\Scripts\pip install --no-index --find-links wheels -r requirements.txt

2. Configure

Copy-Item .env.example .env
# edit .env — see Configuration below

3. Run

.venv\Scripts\python src\server.py

4. Connect from Claude Code (client machine)

claude mcp add --transport http solidworks http://<sw-host>:8080/mcp

Then just ask Claude: "Open bracket.sldprt and create a first-angle 3-view drawing with dimensions, then export it as PDF."

Compatible MCP clients

Any MCP client that supports Streamable HTTP and runs on your machine (or inside the LAN) can connect. Verified examples:

Client	Config
Claude Code	claude mcp add --transport http solidworks http://<sw-host>:8080/mcp
Codex CLI	config.toml: [mcp_servers.solidworks] url = "http://<sw-host>:8080/mcp"
Gemini CLI	gemini mcp add --transport http solidworks http://<sw-host>:8080/mcp
Cursor	mcp.json: { "mcpServers": { "solidworks": { "url": "http://<sw-host>:8080/mcp" } } }
VS Code Copilot	.vscode/mcp.json: { "servers": { "solidworks": { "type": "http", "url": "http://<sw-host>:8080/mcp" } } }
Cline	cline_mcp_settings.json: { "mcpServers": { "solidworks": { "type": "streamableHttp", "url": "http://<sw-host>:8080/mcp" } } }
Windsurf	~/.codeium/windsurf/mcp_config.json: { "mcpServers": { "solidworks": { "serverUrl": "http://<sw-host>:8080/mcp" } } }
Continue / Zed / JetBrains AI Assistant / opencode / Goose	see their MCP docs (url / uri field)

Agent frameworks work too: OpenAI Agents SDK (MCPServerStreamableHttp), LangChain (langchain-mcp-adapters).

Cloud-brokered connectors cannot reach a LAN-only server: Claude Desktop / claude.ai custom connectors and the Anthropic Messages API MCP connector all connect from the vendor's cloud, which is exactly what the trusted-LAN security model blocks.

Configuration

All settings are loaded from .env (see .env.example):

Variable	Default	Description
SW_MCP_HOST	0.0.0.0	Address the server binds to
SW_MCP_PORT	8080	Server port
SW_MCP_SMB_PATH	C:\mcp-share	Server-side folder for screenshots / PDFs that exceed the base64 limit
SW_MCP_SMB_CLIENT_PATH	(empty)	The same folder as seen from the client (e.g. U:\mcp-share); used to rewrite returned paths
SW_MCP_TEMPLATE	(empty)	Drawing template (.drwdot) used by create_drawing
SW_MCP_PAPER_SIZE	A3	Default paper size
SW_MCP_MAX_BASE64	1048576	Max screenshot size (bytes) returned inline as base64; larger images are saved to the shared folder

Security

This server has no authentication. Anyone who can reach the port can drive your SolidWorks instance and read/write files through it.

• Deploy on a trusted LAN only — never expose the port to the internet
• Prefer binding SW_MCP_HOST to a specific LAN interface instead of 0.0.0.0
• Consider OS-level firewall rules restricting access to known client IPs

Tool Reference

File operations

Tool	Description
open_document	Open a SolidWorks document (.sldprt / .sldasm / .slddrw)
close_document	Close the specified document
list_open_documents	List all documents currently open in SolidWorks

Drawing views

Tool	Description
create_drawing	Create a new drawing document from a template
insert_standard_views	Insert independent standard views (no projection alignment, custom scale)
insert_standard_views_aligned	Create first-angle aligned front / top / right views with auto scale
insert_section_view	Create a section view on a parent view
insert_detail_view	Create a detail (magnified) view on a parent view
insert_custom_view	Insert a named-orientation or arbitrary XYZ-rotation view

Annotation

Tool	Description
insert_model_dimensions	Import model dimensions into drawing views
probe_drawing_edges	Inspect visible edges (index / type / coordinates in mm) before dimensioning
add_dimension	Add a linear / diameter / radius / angle dimension between probed edges
auto_add_reference_dimensions	Auto-add reference dimensions (bounding box + circles) for non-parametric geometry
insert_balloon	Insert balloons on an assembly drawing view (optionally filtered by component)
insert_bom_table	Insert a top-level-only BOM table

Export

Tool	Description
capture_drawing	Capture the current drawing as JPEG (inline base64 or shared-folder path)
capture_view	Capture multi-angle screenshots from the 3D model
save_as_pdf	Export the current drawing to PDF
save_drawing	Save the current drawing (.slddrw)

Assembly analysis

Tool	Description
read_assembly_mates	Read all mate relationships of a component in an assembly
get_feature_tree	Read the feature tree of a document

Development

# run all tests (no SolidWorks needed — the COM layer is fully mocked)
.venv\Scripts\pytest tests/ -v

Behavior contracts live in docs/specs/ — specs with status: active describe the expected behavior of shipped features. Design history is in docs/plans/.

See CONTRIBUTING.md for development setup and PR guidelines.

License

MIT