Openscad Wasm

An OpenSCAD Model Context Protocol (MCP) server that runs OpenSCAD in Node.js/TypeScript using WebAssembly (openscad-wasm). No native OpenSCAD installation on the host is required.

Quick Start

1. Run with Docker Compose

By default, the server runs in Docker with restricted privileges:

docker compose up --build

The MCP server listens on http://127.0.0.1:3333/mcp.

2. Configure MCP Client

Add the server to your MCP client configuration (e.g., claude_desktop_config.json):

Using HTTP Transport (default):

{
  "mcpServers": {
    "openscad-wasm": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/client-cli", "http://127.0.0.1:3333/mcp"]
    }
  }
}

Available Tools

OpenSCAD Tools

• openscad_validate: Validates SCAD code and returns syntax/logical diagnostics.
• openscad_export_model: Exports model to stl, 3mf, off, csg, dxf, or svg.
• openscad_render_preview: Generates a server-side WebP render or an interactive 3D preview link.
• openscad_create_preview_link: Generates a URL to open a browser-based interactive 3D viewer.
• openscad_analyze_model: Computes the model's bounding box and triangle count.

Workspace Tools

• workspace_list_files: Lists files in the container workspace.
• workspace_read_file: Reads a file from the workspace.
• workspace_write_file: Writes a file to the workspace.
• workspace_delete_file: Deletes a file from the workspace.

Artifacts

Renders and model exports are saved under ./workspace/artifacts on the host. The MCP tool responses return metadata: path, filename, format, mimeType, sizeBytes, and sha256.

Configuration

Customize runtime limits (memory, timeouts, directories) by copying .env.example to .env and editing the environment variables.

Known Limitations

• Performance: Complex models can be slow or memory-intensive inside WebAssembly.
• Visuals: WebP previews do not preserve OpenSCAD colors, GUI helpers, or 2D camera perspectives.
• Assets & Libraries: Fonts and external libraries are not bundled; you must upload necessary files to the workspace first.
• Format Support: Build-specific limits may affect exports (e.g., 3mf is currently unsupported).

License

MIT License. See LICENSE for details. Dependencies (openscad-wasm, sharp) carry their own respective licenses.