SolidWorks CAD Assistant & MCP Server

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Python MCP server for SolidWorks automation with 154 tools, plus an optional agent/prompt-testing layer for AI-assisted workflows.

See it work

Make a 100 x 50 x 10 mm AISI 1020 mounting plate with four M5 clearance holes, 10 mm in from each edge, and draw it fully dimensioned. Stack two of them 10 mm apart, check the result, and draw the assembly with a BOM.

The 58 tool calls an agent made from that prompt, run against SolidWorks 2026 through the same MCP tools a client calls, and recorded (sped up five times). Each result is checked against a hand calculation: the plate's volume and mass, the 10 mm gap and the BOM quantity. This is a replay of the calls, not a recorded model session.

Note: the demo is not perfect, and is not the most efficient way to get this result. The run pauses after each call so it can be read, and the calls are chosen to show what the tools can do: every sketch dimension is added one at a time, and the mate distance is stepped down only so the plates are seen coming together.

The walkthrough in the docs has the agent's plan and every call with its arguments. Run it yourself with the README demo; the calls are also in plate_stack_calls.json.

1. Sketch (24 calls): create_sketch on Top; four add_line for the 100 x 50 outline; add_circle for each Ø5.5 hole; add_sketch_dimension for the 100, the 50, one Ø5.5 and each hole 10 mm from two edges; add_sketch_constraint making the other three holes equal; exit_sketch
2. Check and extrude: check_sketch_fully_defined, create_extrusion 10 mm (+49 049.7 mm³ read back)
3. Material and check: list_model_dimensions (finds the Ø5.5 by value), set_material AISI 1020, verify_model (volume, mass 0.3875 kg, size, 1 feature, 1 body)
4. Plate drawing: generate_drawing_package PS-01 (A3, four views, every model dimension laid out with no overlaps, notes, title block, PDF), auto_center_marks
5. GD&T: add_datum_tag A, B and C, then add_gtol ⊕ Ø0.2 Ⓜ A|B|C on the Ø5.5
6. Assembly: insert_component twice, list_components, add_mate Front and Right coincident and Top planes 60 mm apart, set_dimension stepping that distance down to 20 mm (10 calls), verify_model (2 parts, 3 mates, no interference; the stack measures 30 mm, so the gap is 10 mm)
7. Assembly drawing: set_custom_property Material, generate_drawing_package PS-02 with include_bom (the BOM above the isometric: Demo Plate, QTY 2), then the same datums and position frame

Overview

Tried it? Tell us what worked and what didn't in a feedback issue. Reports from real setups decide what gets fixed next.

This project focuses on practical SolidWorks automation with an AI-friendly loop:

1. describe intent
2. generate a plan
3. execute MCP tools
4. inspect results
5. iterate

It includes:

• core MCP runtime for SolidWorks tool execution
• COM/VBA routing and adapter safety wrappers
• tool coverage across modeling, sketching, drawing, analysis, export, automation, templates, and macros
• optional agent orchestration/testing utilities under src/solidworks_mcp/agents/

Demos

Each GIF is a live test driving SolidWorks 2026 through the MCP tools, with the call and its result captioned beneath. Click one to see what it checks, a prompt that asks for it, and its tool calls.

See every demo in the docs: what each one shows, its prompt, every tool call with its arguments (all 58 for the demo at the top), and how to run them yourself.

Supported Today

• Windows + SolidWorks COM automation for the main CAD lifecycle.
• Modeling, sketching, drawing, analysis, export, automation, templates, and macro tools.

Not Yet / Simulated

• Mock adapter output is simulated and should not be treated as engineering truth.
• Live 3D viewport streaming in a UI.
• Checkpoint-level interference validation.
• Simple simulation and fluid workflows
• Simple Topology Optimization via SimulationXpress etc.

Install

You need Windows 10 or 11, SolidWorks (opened at least once), Python 3.13+ and Git. Then, in PowerShell:

git clone https://github.com/andrewbartels1/SolidworksMCP-python.git
cd SolidworksMCP-python
.\install.ps1

install.ps1 creates a .venv in the folder, installs the server into it, then runs the guided setup:

1. It finds your SolidWorks version and the MCP clients on your PC: Claude Desktop, Claude Code, VS Code, Cursor and LM Studio.
2. You pick which clients to connect.
3. It starts the server once to check that it lists its tools (in mock mode, so SolidWorks isn't touched).
4. It adds a solidworks entry to each client you picked, then tells you what to restart.

Nothing needs a login or an API key, and the server runs only on your PC. Setup changes only the solidworks entry in each client's config. It backs the file up first and never shows or changes your other servers. Other entries that start this server the old way (run-mcp.ps1 and the like) are offered for removal, so tools don't load twice.

To check it worked: open SolidWorks, restart your client, and ask "What model is open in SolidWorks?"

If scripts are blocked, run powershell -ExecutionPolicy Bypass -File .\install.ps1. If Python isn't found, reinstall it from python.org with Add python.exe to PATH ticked. More fixes are in Troubleshooting.

Connect your client

install.ps1 runs this for you. Run it again whenever you want to add a client, or move the entry to another copy of the project:

.\.venv\Scripts\solidworks-mcp.exe setup

Option	What it does
--client claude-desktop	Configure one client without the list. Repeat it for several (claude-code, vscode, cursor, lmstudio).
--dry-run	Show what would change, and change nothing.
--yes	Don't ask: configure every client found.
--remove	Take the solidworks entry out again.
--replace-old	Remove older entries for this server without asking.
--mock	Configure mock mode, which answers without SolidWorks (for trying the tools).

To set up a client by hand instead, each one runs the same program. Use the full path to the .venv in your copy of the project, shown below as C:\path\to\SolidworksMCP-python.

Add this to claude_desktop_config.json, alongside anything already in it. Depending on how Claude Desktop was installed, the file is in one of:

• %LOCALAPPDATA%\Claude-Data\claude_<id>\ (current releases)
• %LOCALAPPDATA%\Packages\Claude_<id>\LocalCache\Roaming\Claude\
• %APPDATA%\Claude\

{
  "mcpServers": {
    "solidworks": {
      "command": "C:\\path\\to\\SolidworksMCP-python\\.venv\\Scripts\\solidworks-mcp.exe",
      "args": []
    }
  }
}

Quit Claude Desktop from the system tray (closing the window isn't enough) and reopen it. Settings > Developer should show solidworks as running.

claude mcp add --scope user solidworks -- C:\path\to\SolidworksMCP-python\.venv\Scripts\solidworks-mcp.exe

Run /mcp in a new session to check that solidworks is connected.

Add this to %APPDATA%\Code\User\mcp.json:

{
  "servers": {
    "solidworks": {
      "type": "stdio",
      "command": "C:\\path\\to\\SolidworksMCP-python\\.venv\\Scripts\\solidworks-mcp.exe",
      "args": []
    }
  }
}

Run MCP: List Servers from the Command Palette and start solidworks. Its output should end with Discovered 154 tools (the count grows as tools are added).

Add this to %USERPROFILE%\.lmstudio\mcp.json:

{
  "mcpServers": {
    "solidworks": {
      "command": "C:\\path\\to\\SolidworksMCP-python\\.venv\\Scripts\\solidworks-mcp.exe",
      "args": []
    }
  }
}

Restart LM Studio and enable solidworks in the Program tab.

For mock mode, which needs no SolidWorks, use "args": ["--mock"]. Linux and WSL work for the docs, the tests and mock mode, but not for driving SolidWorks.

Set these in your client's env block for the server, or in the shell before starting it by hand. Every SOLIDWORKS_MCP_<FIELD> maps to the config field of the same name.

SolidWorks-as-Code session logging (off by default). Logs every adapter tool call to a local SQLite database, so a session can be replayed or exported as a runnable Python script (see docs/getting-started/solidworks-as-code.md).

Variable	Default	Meaning
SOLIDWORKS_MCP_SOC_LOGGING_ENABLED	false	Turn logging on.
SOLIDWORKS_MCP_SOC_SESSION_ID	(generated)	Session name to log under. If unset while logging is on, a soc-YYYYMMDD-HHMMSS id is generated at startup.
SOLIDWORKS_MCP_SOC_DB_PATH	.solidworks_mcp/agent_memory.sqlite3	Override the database file.

$env:SOLIDWORKS_MCP_SOC_LOGGING_ENABLED = "true"
$env:SOLIDWORKS_MCP_SOC_SESSION_ID = "my-bracket"
.\.venv\Scripts\solidworks-mcp.exe
# ...work in your MCP client...
.\.venv\Scripts\python.exe -m solidworks_mcp.agents.soc_exporter my-bracket my_bracket.py

It works only with the circuit-breaker adapter wrapper (the default for real SolidWorks); the mock adapter does not log.

API docs index auto-refresh (on by default). The API-lookup tools (lookup_api_interface, lookup_api_method, find_related_api_members) and search_solidworks_api_help read a JSON index built by discover_solidworks_docs. When the index is older than the threshold, the next lookup rebuilds it.

Variable	Default	Meaning
SOLIDWORKS_MCP_DOCS_INDEX_AUTO_REFRESH	true	Rebuild a stale index automatically. No-op without SolidWorks + win32com; a failed rebuild keeps serving the existing index.
SOLIDWORKS_MCP_DOCS_INDEX_MAX_AGE_DAYS	21	Age after which the index counts as stale.

Contributing

install.ps1 gives you an editable install, so code changes take effect the next time a client starts the server. For the development tools, install the extras:

.\.venv\Scripts\python.exe -m pip install -e ".[dev,test,docs]"

.\dev-commands.ps1 lists the common workflows:

• dev-install: install or update the local dev environment
• dev-test: run the standard test suite (the CI-safe subset)
• dev-test-full: run the full suite, including smoke and integration paths
• dev-lint and dev-format: lint checks and formatting
• dev-docs-build, dev-docs-strict and dev-docs-audit: build the docs, build them failing on warnings, or write an audit report to .generated/docs

To mirror GitHub Actions CI locally (Ubuntu, the conda env from solidworks_mcp.yml, and make test), run .\scripts\run-ci-local.ps1. The first run builds the image; add -NoBuild to re-run tests without rebuilding.

Docs

• Main docs site: https://andrewbartels1.github.io/SolidworksMCP-python/
• Home/overview: docs/index.md

Key docs sections:

• Getting Started: docs/getting-started
• MCP Server Guide: docs/user-guide
• Tool Catalog: docs/user-guide/tool-catalog
• Agents and Skills: docs/agents
• Planning/Roadmap: docs/planning

Direct links:

• Installation
• Quick Start
• Tutorial: U-Joint Assembly Build
• Tutorial Tracks
• VS Code MCP Setup
• Architecture
• Agents and Prompt Testing
• PydanticAI and Schemas

License

MIT License. See LICENSE.