cadlens-mcp

A Model Context Protocol server that wraps the Cadlens CAD parsing API so MCP-aware LLM clients (Claude Desktop, Claude Code, Cursor, Zed, Windsurf) can parse CAD files (.dwg, .dxf, .dwf, .dwfx, .dgn V7, .pdf, max 100 MB) and reason over the extracted entity, layer, and metadata payloads.

Cadlens converts CAD drawings into structured JSON without requiring AutoCAD or any desktop software — learn more at cadlens.co.

Install

Get an API key from the Cadlens dashboard first — keys start with cadl_ and are created in the dashboard for free.

Claude Desktop / Cursor / Windsurf

Add to your MCP client config (e.g. ~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

{
  "mcpServers": {
    "cadlens": {
      "command": "npx",
      "args": ["-y", "@cadlens/mcp-server"],
      "env": {
        "CADLENS_API_KEY": "cadl_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
      }
    }
  }
}

Claude Code CLI

claude mcp add cadlens \
  --env CADLENS_API_KEY=cadl_xxx \
  -- npx -y @cadlens/mcp-server

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Development (build from source)

npm install
npm run build

export CADLENS_API_KEY="cadl_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
node dist/index.js

Tools

Tool	What it does
cadlens_parse_file	Upload a local CAD file, poll until parsed (5 min budget), return summary.
cadlens_parse_url	Download a CAD file from a URL, then parse it like parse_file.
cadlens_get_job	Cheap status check (PENDING / PROCESSING / COMPLETED / FAILED).
cadlens_get_result	Fetch parsed content. mode: summary (default), entities_by_type, entities_on_layer, full.
cadlens_refresh_image_url	Re-fetch the 1h presigned PNG URL without re-downloading the full result.
cadlens_list_jobs	The 100 most recent jobs for the configured API key.
cadlens_delete_job	Delete a job and its S3 artifacts. Irreversible.

Configuration

Env var	Required	Default	Notes
CADLENS_API_KEY	yes	—	Created in the CADLens dashboard.
CADLENS_API_BASE	no	https://api.cadlens.co/v1	Set to http://localhost:3001/v1 for local dev.
WEBHOOK_PORT	no	0 (random)	Port for the in-process webhook receiver.
WEBHOOK_PUBLIC_URL	no	unset	Set to a tunnel URL (ngrok/cloudflared) to let CADLens hit the local receiver. When set, parse calls auto-register the webhook and the poller short-circuits on receipt.
REQUEST_TIMEOUT_MS	no	30000	Per-HTTP-request timeout for CADLens calls.

Webhook short-circuit (optional)

If WEBHOOK_PUBLIC_URL is set, parse_file / parse_url register a per-process webhook URL alongside the upload. The webhook handler updates an in-memory job-state cache; the poller checks that cache before each HTTP GET and returns early when COMPLETED / FAILED arrives. This trims worst-case latency by up to one full poll tick (~1 s) without changing the tool surface.

Example tunnel setup:

cloudflared tunnel --url http://localhost:8787 &
export WEBHOOK_PORT=8787
export WEBHOOK_PUBLIC_URL="https://<your-tunnel>.trycloudflare.com"

Development

npm run typecheck
npm run lint
npm test
npm run smoke   # tools/list smoke test against built binary

Project-scoped Claude agents

This repo ships five agents under .claude/agents/:

• cadlens-api-debugger — diagnoses unexplained CADLens 4xx/5xx using mcp-server-reference.md.
• mcp-tool-tester — drives JSON-RPC against the built server to validate tool responses.
• mcp-tool-implementer — scaffolds new tools following the existing src/tools/* pattern.
• cad-drawing-summarizer — uses the MCP tools to summarize a CAD file in natural language.
• cad-layer-inspector — drills into a single layer of a parsed drawing.

Links

• Cadlens official website
• Cadlens API documentation
• Cadlens pricing
• DWG parser for AI agents
• npm package
• GitHub repository

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GitHub Topics

Add these topics to this repo for discovery: mcp mcp-server model-context-protocol ai-agents claude cad dwg dxf cad-api llm-tools engineering-api

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License

MIT