QCAD MCP
AI-driven 2D CAD automation — DXF/DWG parsing, 3D extrusion, persistent file depot, room analysis, and full CRUD management. 7 MCP tools 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 |
| Tool | Access | Purpose |
|---|
plan_depot | READ | List files in the persistent CAD depot with metadata |
plan_info | READ | DXF metadata: layers, entity counts, bounding box, blocks |
plan_create | MUTATE | Create DXF from primitives (line, rect, circle, text, polyline) |
plan_to_svg | MUTATE | DXF → SVG preview with layer filtering |
plan_extrude | MUTATE | DXF walls → 3D STL mesh (configurable height/thickness) |
plan_export | MUTATE | DXF → SVG/PNG/PDF (ezdxf or QCAD Pro) |
plan_analyse | READ | Room detection, area calculation, door/window identification |
plan_measure | READ | Measure distances and lengths in a DXF |
plan_wall_data | READ | Extract wall segments as BIM-ready JSON (QCAD Pro) |
plan_beam_analysis | READ | 2D beam FEM analysis (numpy, no QCAD needed) |
plan_dimension | MUTATE | Add aligned/linear/angular/radial dimensions (QCAD Pro) |
plan_text | MUTATE | Add text annotations (QCAD Pro) |
plan_hatch | MUTATE | Add hatch patterns (QCAD Pro) |
plan_block_insert | MUTATE | Insert CAD blocks from library (QCAD Pro) |
plan_array | MUTATE | Rectangular/polar array patterns (QCAD Pro) |
plan_convert | MUTATE | Convert between DXF and DWG (QCAD Pro) |
plan_modify | MUTATE | Delete/offset/rename/freeze layers |
plan_script | MUTATE | Execute arbitrary ECMAScript in QCAD Pro |
plan_render | MUTATE | High-fidelity SVG/PDF/BMP render via QCAD Pro |
plan_exec | MUTATE | Quick ECMAScript snippet execution |
plan_blocks | READ | Search 4800+ CAD blocks from part library |
plan_blocks_download | MUTATE | Download a block DXF from library |
plan_scripts_search | READ | Search QCAD ECMAScript scripts gallery |
plan_scripts_download | MUTATE | Download a script from gallery/Gist |
qcad_status | READ | QCAD Pro install/running/version report |
plan_agentic | MUTATE | NL → ECMAScript via AI sampling (MCP only, needs QCAD Pro) |
plan_transpile | MUTATE | AutoLISP → QCAD ECMAScript translation (MCP only, needs QCAD Pro) |
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. Baroque church, mob compound, art museum presets |
/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 + npm install
start.ps1 # kills zombies, starts backend + frontend, opens browser
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_modify)
↓
Clean up in QCAD / plan_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_modify | Merge short segments, delete stray marks, re-layer, re-dimension |
Two approaches:
- 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.
- 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_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:
- 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.
- €50 individual is friction-free "impulse buy" pricing — no PO approval needed, no vendor negotiation. You just buy it.
- 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.
- QCAD/CAM at €132 captures the CNC/manufacturing niche — a separate, higher-value market.
- 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 — zero errors across 5 MCP tools + depot CRUD
- Frontend: Biome +
tsc — zero errors across 9 TypeScript pages
- Protocol: FastMCP 3.2 SSE transport + 10 REST endpoints
- Automation: Justfile recipes for all fleet operations
- AI Protocol: FastMCP 3.2 with SSE transport
License
MIT — see LICENSE.