qcad-mcp

QCAD MCP

AI-driven 2D CAD automation — DXF/DWG parsing, 3D extrusion, persistent file depot, room analysis, and full CRUD management. 12 MCP tools (8 portmanteaus + 4 Prefab cards) for DXF processing. Your AI assistant becomes a QCAD Pro operator.

You might use this if…	You want your AI to process floor plans programmatically, convert DXF to 3D for Resonite/Unity3D, maintain a persistent CAD file depot, or automate drafting workflows.
What it connects to	ezdxf (free Python engine) for all parsing + rendering + extrusion + analysis
Ports	Backend 11966, Dashboard 11967
Start	just bootstrap then start.ps1

MCP Tools

v0.5.0 portmanteau surface: each tool takes an op discriminator plus the op's parameters (old per-op names survive only as webapp-internal aliases).

Tool	Access	Purpose
plan	READ/MUTATE	Core ezdxf ops: info, to_svg, extrude, stack, obj, glb, drawings, export, analyse, create, depot
plan_edit	MUTATE	convert (DWG↔DXF via QCAD Pro), modify (layers/entities)
plan_annotate	READ/MUTATE	dimension, measure, text, hatch, block_insert, array, wall_data, beam_analysis
plan_pro	MUTATE	QCAD Pro: script, render, exec (ECMAScript)
plan_library	READ/MUTATE	blocks, blocks_download, scripts_search, scripts_download
plan_ai	MUTATE	generate (NL floor plan), agentic (NL workflow), transpile (AutoLISP), sampling (host LLM reason)
plan_bim	READ/MUTATE	auto_dimension, building_meta, to_ifc_data (BIM handoff)
qcad	READ	status (QCAD Pro install), help (live catalog), shutdown (orderly exit)
show_qcad_status_card	READ	Prefab card: QCAD Pro status
show_depot_card	READ	Prefab card: depot files
show_beam_analysis_card	READ	Prefab card: beam FEA results
show_building_meta_card	READ	Prefab card: building metadata

Fleet Crossconnects (Companions)

qcad-mcp works completely standalone. You can optionally connect it with companion servers in the sandraschi fleet to unlock extended features:

Companion Server	Feature Unlocked	Status	Setup
blender-mcp	3d-scene-extrusion, render-dxf-layouts	Optional	Install Guide
freecad-mcp	2d-draft-to-parametric-3d	Optional	Install Guide

Self-Contained Companions: Fleet companions operate independently. Installing companions does not trigger transitive dependency chains.

CAD Depot (Persistent File Storage)

All CAD files are stored in a persistent depot at %LOCALAPPDATA%\qcad-mcp\depot — survives server restarts and system reboots. Configurable via QCAD_MCP_DEPOT env var.

Depot CRUD via REST API:

Endpoint	Method	Description
/api/v1/depot	GET	List all files with metadata (size, dates, description, tags)
/api/v1/depot/{name}	GET	Download a DXF file
/api/v1/depot/{name}	PUT	Rename or update description/tags
/api/v1/depot/{name}	DELETE	Remove file + metadata sidecar
/api/v1/depot/create	POST	Create DXF from JSON entity spec (line, rect, circle, text, polyline)
/api/v1/depot/upload	POST	Upload DXF/DWG directly to depot

REST API

Endpoint	Method	Description
/api/v1/status	GET	Server health, ezdxf version, QCAD Pro status
/api/v1/upload	POST	Upload DXF/DWG (also saved to depot)
/api/v1/download/{name}	GET	Download SVG/STL/PDF/PNG outputs
/api/v1/files	GET	List all files (depot + outputs)
/api/v1/depot/*	GET/PUT/DELETE	Full CRUD on the persistent CAD depot
/api/v1/control/tool	POST	Execute any MCP tool
/api/v1/logs/stream	GET	SSE live log stream
/api/v1/chat	POST	Chat with CAD expert via Ollama
/api/v1/settings	GET/PUT	LLM + extrusion defaults + QCAD Pro path

Webapp Pages

Route	Page	Description
/	Dashboard	Hero banner, QCAD Pro status panel, depot stats, ezdxf version
/demo	AI CAD Demo	NL → floor plan → SVG → 3D STL. Preset cards, pipeline stepper, tabbed results
/chat	Chat	Streaming LLM chat, skill-first, 6 personalities, history, export
/inbox	Inbox	New-file review queue with inline preview and Viewer links
/tools	Tools	Portmanteau catalog with op chips + Playground deep-links
/skills	Skills	Skill browser (same files the Chat uses as system prompt)
/depot	Depot	Full CRUD file browser with SVG preview, create DXF wizard, upload, rename, delete
/viewer	Viewer	DXF upload + SVG preview with per-layer toggle
/extrude	Extrude	DXF → STL with wall height/thickness/wall-layer controls
/analyse	Analyse	Room detection, area table, door/window list
/layers	Layers	Layer visibility, freeze/lock, rename, bulk operations
/blocks	Blocks	Search 4800+ CAD blocks from library with download
/scripts	Scripts	Browse QCAD ECMAScript scripts gallery + save local scripts
/agentic	AI Agent	Autonomous multi-step CAD workflow (QCAD Pro)
/batch	Batch	Run info/analysis/extrude across all depot files. STL batch extrude with gallery
/pipeline	Pipeline	5-step wizard: describe → SVG → analyse → STL → FreeCAD wall data export
/playground	Playground	Tool API tester: select any tool, edit JSON args, execute, view raw response
/models	Models	Uploads vs outputs listing with download
/logs	Logs	Live SSE log viewer with filter/export/pause
/settings	Settings	LLM provider/model, extrusion defaults, QCAD Pro path
/help	Help	10-tabbed reference: QCAD, ezdxf, tools, pipeline, formats, fleet
docs/floorplan-sources.md	—	Free, paid, and historic floorplan sources + raster→DXF pipeline

Quick Start

just bootstrap   # uv sync + bun install
start.ps1        # kills zombies, starts backend + frontend, opens browser

Install (Claude Desktop, Windows)

irm https://github.com/sandraschi/qcad-mcp/releases/latest/download/install.ps1 | iex

Installs the stable qcad-mcp.mcpb bundle into Claude Desktop. Other clients (Cursor, VS Code, OpenCode): use uvx with the stdio entry:

{
  "mcpServers": {
    "qcad-mcp": {
      "command": "uv",
      "args": ["run", "--directory", "D:\\Dev\\repos\\qcad-mcp", "run_server.py"]
    }
  }
}

MCP Client Config

{
  "mcpServers": {
    "qcad": {
      "url": "http://localhost:11966/sse",
      "transport": "sse"
    }
  }
}

Raster → DXF Pipeline (Planned)

Scanning a floorplan print into a working DXF is straightforward:

Book/magazine page → scanner (300-600 DPI)          inkscape-mcp
                         ↓                          (Trace Bitmap)
                    Potrace / Inkscape                    ↓
                         ↓                          QCAD MCP
                    Raw vector DXF                    (plan_edit(op="modify"))
                         ↓
                    Clean up in QCAD / plan_edit(op="modify")

Step	Tool	What it does
Scan	Any scanner	300-600 DPI, grayscale or B&W, save as PNG/TIFF
Vectorize	inkscape-mcp trace_bitmap() or potrace CLI	Converts raster lines to SVG paths
Convert	SVG → DXF (via potrace or ezdxf)	Opens in any CAD program
Clean	qcad-mcp plan_edit(op="modify")	Merge short segments, delete stray marks, re-layer, re-dimension

Two approaches:

1. inkscape-mcp route — send the scanned PNG to inkscape-mcp's trace_bitmap() tool, get back SVG with proper path geometry. The SVG imports cleanly into QCAD as workable entities.
2. potrace in qcad-mcp — add a plan_raster_to_dxf(file_name) tool that wraps potrace + ezdxf. Self-contained, no external server needed.

Either way, the result goes through plan_edit(op="modify") for cleanup (delete noise, merge wall segments, re-assign layers, re-add dimensions). The baroque church preset in the Demo page proves the parametric geometry works — scanning would let you capture actual existing buildings.

QCAD Pro Pricing — €50? Really?

QCAD Professional sells for €50.40 for a single-user license — lifetime, no subscription. That looks absurd next to AutoCAD at $2,000+/year, but RibbonSoft's revenue model is more nuanced:

Product	Price	Market
Community Edition	Free (GPLv3)	Hobbyists, students, tinkerers
QCAD Professional	€50.40	Individual professionals, small firms
QCAD Pro Site License	€440.40	Companies (unlimited seats, single site)
QCAD Pro Server License	€583.20	Self-hosted deployment
QCAD Pro Scalable Server	€1,771.20	Enterprise-scale
QCAD/CAM (CNC add-on)	€132.00	Manufacturing
QCAD/CAM Site License	€1,173.60	CNC shops
Books / E-Books	€40–42 each	Documentation, passive income

The strategy is open-core freemium with enterprise site-license extraction:

1. Community Edition is genuinely free and capable (GPLv3). It's a giant funnel — architects, makers, and students learn on it, recommend it, and eventually their employer buys a site license.
2. €50 individual is friction-free "impulse buy" pricing — no PO approval needed, no vendor negotiation. You just buy it.
3. Site & server licenses (€440–€1,771) are where the real revenue lives. An architecture firm with 20 seats paying €440 beats 200 individuals paying €50. And server licenses for SaaS/on-prem deployment scale further.
4. QCAD/CAM at €132 captures the CNC/manufacturing niche — a separate, higher-value market.
5. Books at €40 are pure margin — the manual is already written, printing costs are negligible.

RibbonSoft is a Swiss GmbH (limited company) based in Sarnen, not retirees. 100% of their office energy is from Swiss hydropower (they're proud enough to put it in the footer). They've been doing this since 1999 — 26+ years of sustainable bootstrapping.

Who pays? Ganesh in Bangalore runs the Community Edition for his residential projects — it handles DXF perfectly for Indian building code drawings. When a client demands DWG or PDF export, he drops €50 on Pro — one job pays for it. As his practice scales past 5 seats, he graduates to a site license. Meanwhile a European architecture firm pays €440 for compliance reasons and never thinks twice. The Bay Area Autodesk tax ($2,500+/year) only makes sense when someone else is paying.

€50 clears every threshold, everywhere. No PO approval, no vendor negotiation, no subscription clock. You buy it once and own it.

Quality Stack

• Python: Ruff linter + format, Pyright typecheck (0 errors) — src/ + run_server.py
• Frontend: Biome + tsc --noEmit + bun lockfile — 22 TypeScript pages
• Protocol: FastMCP 3.4 (stdio + HTTP /mcp) + 40 REST routes
• Tools: 12 MCP tools (8 portmanteaus + 4 Prefab cards) with READ_ONLY/MUTATING annotations
• Automation: Justfile recipes for all fleet operations
• Tests: pytest (78+) + Playwright e2e specs

License

MIT — see LICENSE.