Content
# SolidWorks MCP Server
[](https://www.typescriptlang.org/)
[](https://modelcontextprotocol.io)
[](https://nodejs.org/)
[](https://opensource.org/licenses/MIT)
[](https://www.microsoft.com/windows)
A Node.js MCP server for automating SolidWorks via COM interop. Connects AI assistants (Claude Desktop, etc.) to SolidWorks for CAD automation tasks.
> **Project Status: Alpha / Experimental**
>
> This project is under active development. While the architecture is in place and basic operations (sketch planes, simple extrusions) have been demonstrated, **most tools have not been validated against a live SolidWorks instance**. Expect rough edges, COM quirks, and incomplete functionality. Contributions and testing reports are very welcome.
## How It Works
The server exposes SolidWorks operations as MCP tools over stdio. An intelligent routing layer handles a key limitation of Node.js COM bridges: methods with 13+ parameters often fail via direct COM calls.
- **Simple operations (12 params or fewer)** - Direct COM call via `winax`
- **Complex operations (13+ params)** - Auto-generated VBA macro executed by SolidWorks
- **Failed operations** - Automatic fallback with error context
## Prerequisites
- **Windows 10/11** (required - COM interop is Windows-only)
- **SolidWorks 2021-2025** (licensed, installed)
- **Node.js 20+**
- An MCP-compatible client (Claude Desktop, etc.)
## Installation
```bash
git clone https://github.com/vespo92/SolidworksMCP-TS.git
cd SolidworksMCP-TS
# Install dependencies (compiles winax native module for your system)
npm install
# Build TypeScript
npm run build
```
> **Note:** The `winax` native module must be compiled locally on each Windows machine. Global npm installation does not work.
## Configure Claude Desktop
Add to your `claude_desktop_config.json`:
```json
{
"mcpServers": {
"solidworks": {
"command": "node",
"args": ["C:/path/to/SolidworksMCP-TS/dist/index.js"],
"env": {
"SOLIDWORKS_PATH": "C:\\Program Files\\SOLIDWORKS Corp\\SOLIDWORKS",
"ADAPTER_TYPE": "winax-enhanced"
}
}
}
}
```
## Available Tools
The server registers tools across these categories:
| Category | Tools | Status |
|----------|-------|--------|
| **Modeling** | create_part, create_extrusion, create_revolve, create_sweep, create_loft, create_fillet, create_chamfer, etc. | Partially tested |
| **Sketch** | create_sketch, add_line, add_circle, add_rectangle, add_arc, add_constraints, dimension_sketch | Basic ops verified |
| **Drawing** | create_drawing_from_model, add_drawing_view, add_section_view, add_dimensions, etc. | Untested |
| **Export** | export_file (STEP, IGES, STL, PDF, DWG, DXF), batch_export | Untested |
| **Analysis** | get_mass_properties, check_interference, measure_distance, check_geometry | Untested |
| **VBA Generation** | generate_vba_script, vba_sheet_metal, vba_configurations, vba_equations, etc. | Code generation works; execution untested |
| **Macro** | macro_start_recording, macro_stop_recording, macro_export_vba | Untested |
**"Partially tested"** means the tool has been run against SolidWorks at least once but not comprehensively. **"Untested"** means only mock/unit tests exist (if any).
## Architecture
```
MCP Protocol (stdio)
|
Tool Registry (index.ts)
|
Feature Complexity Analyzer --- routes by param count
| |
Direct COM (winax) VBA Macro Generator
| |
+--------------------+
|
SolidWorks COM API
```
### Key Design Decisions
- **COM parameter limit workaround**: SolidWorks API methods like `FeatureExtrusion3` take 20+ parameters. Node.js COM bridges choke on these. The complexity analyzer detects this and generates a VBA macro instead.
- **Never pass `null` to COM**: Use `undefined` for optional parameters. COM interprets `null` as `VT_NULL`, causing type mismatch errors (this was the root cause of SelectByID2 failures).
- **Feature tree traversal over SelectByID2**: `FeatureByPositionReverse()` + `GetTypeName2()` is more reliable for finding sketches than `SelectByID2`.
- **Winston logger only**: Never use `console.*` - it corrupts the JSON-RPC stdio transport.
## Development
```bash
npm run build # TypeScript compile
npm run dev # Hot-reload dev server (tsx watch)
npm run check # TypeScript + Biome lint in one command
npm run lint # Biome lint check
npm run lint:fix # Biome auto-fix
npm run format # Biome format
npm run typecheck # Type check without emit
```
## Testing
See [TESTING.md](TESTING.md) for the full testing guide.
```bash
# Unit tests (mock adapter, no SolidWorks needed)
USE_MOCK_SOLIDWORKS=true npm test
# Watch mode
npm run test:watch
```
**Current test status**: Unit tests exist for config and environment utilities. Most tool modules lack test coverage. Integration tests require a Windows machine with SolidWorks and have not been run in CI.
## Known Issues & Limitations
- **No CI integration testing** - Tests only run against mocks. Real SolidWorks integration tests require a self-hosted Windows runner that doesn't exist yet.
- **winax compilation** - Must be compiled locally on each machine. No pre-built binaries.
- **Edge.js adapter** - Defined in architecture but not implemented.
- **PowerShell bridge** - Defined in architecture but not implemented.
- **Connection pooling / circuit breaker** - Referenced in code but not battle-tested.
- **Performance metrics are unverified** - No real benchmarking has been done.
## What Has Worked
Based on development testing:
- Connecting to a running SolidWorks instance via COM
- Creating sketch planes and basic sketch geometry
- Simple extrusions with limited parameters
- Feature tree traversal for sketch selection
- VBA macro code generation (execution path needs more testing)
## Roadmap
- [ ] Comprehensive integration test suite on real SolidWorks
- [ ] CI with self-hosted Windows runner
- [ ] Validate all modeling tools end-to-end
- [ ] Validate drawing and export tools
- [ ] Edge.js adapter for .NET runtime path
- [ ] PowerShell bridge as alternative COM path
- [ ] Performance benchmarking with real metrics
## Contributing
See [CONTRIBUTING.md](CONTRIBUTING.md) for guidelines.
Key areas where help is needed:
- **Testing against real SolidWorks** - The biggest gap. If you have SolidWorks, running tools and reporting results is extremely valuable.
- **COM interop edge cases** - Different SolidWorks versions behave differently.
- **Additional tool implementations** - Many SolidWorks API methods aren't exposed yet.
## Troubleshooting
For `winax` native build failures on Windows 11 Build 26200+ / VS 2022
BuildTools 17.14+ (issue #23) and other install-time problems, see
[TROUBLESHOOTING.md](TROUBLESHOOTING.md).
### COM Registration Issues
```powershell
regsvr32 "C:\Program Files\SOLIDWORKS Corp\SOLIDWORKS\sldworks.tlb"
```
### Build Issues
```bash
rm -rf node_modules dist
npm install
npm run build
```
### Debug Logging
```bash
ENABLE_LOGGING=true LOG_LEVEL=debug node dist/index.js
```
## License
MIT - See [LICENSE](LICENSE)
## Acknowledgments
- [winax](https://github.com/nicedreams/node-activex) - COM bridge for Node.js
- [Anthropic MCP](https://modelcontextprotocol.io) - Model Context Protocol
- SolidWorks API documentation
