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caliperhq

jscad-mcp

@caliperhq/jscad-mcp is an MCP server that renders .jscad files to PNG using the OpenJSCAD geometry kernel and returns the images directly into Claude’s context. A live web viewer runs alongside the server — every render Claude produces is pushed to the viewer in real time via SSE, so you see exactly what Claude sees.

Cycloidal drive rendered via jscad-mcp

Install

Section titled “Install”
Terminal window
npm install -g @caliperhq/jscad-mcp

Or run without installing:

Terminal window
npx @caliperhq/jscad-mcp

Claude Desktop MCP config

Section titled “Claude Desktop MCP config”

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "jscad": {
      "command": "npx",
      "args": ["@caliperhq/jscad-mcp"]
    }
  }
}

What it does

Section titled “What it does”
  • Renders .jscad files to PNG via the OpenJSCAD kernel
  • Returns images directly into Claude’s context window (visual feedback loop)
  • Streams every render to a live web viewer over SSE
  • Exposes tools for highlighting parts, labeling, slicing, and standard view angles
  • Native binding via headless-gl — no GPU required

Full documentation

Section titled “Full documentation”

The canonical README — including platform-specific build prerequisites, Node 24 workarounds, and a full tool reference — lives in the repo.

Full documentation →