CadGPT

Status: Active development

CadGPT turns ChatGPT into a drawing-centric AutoCAD execution environment. ChatGPT remains the reasoning surface; CadGPT provides the local control plane, drawing binding, AutoLISP/Job orchestration, registry discovery, diagnostics, the AutoCAD add-in, and the CAD MCP bridge.

ChatGPT / CadGPT plugin
        ⇅
OpenAI Secure MCP Tunnel
        ⇅
CadGPT slim admission/control plane
        ↓
WorkRegistration + ToolLease
   ├── FILE
   └── CAD / HYBRID
          ↓
        CAD MCP
          ↓
       AutoCAD

The AutoCAD add-in can host ChatGPT in a dockable palette, but the add-in UI is not CAD authority. CadGPT runtime/work binding remains authoritative.

Current product contract

• explicit launch through the CadGPT/CG plugin or literal @cadgpt / @cg;
• one active work binds one drawing;
• current CAD facts are read fresh from the bound drawing;
• while CG is active with a bound drawing, requests such as draw / redraw / create / add / modify / vẽ / vẽ lại / tạo / sửa target AutoCAD by default;
• external image generation is used only when the user explicitly asks for an image/render/illustration rather than CAD output;
• AutoCAD is never launched implicitly by the MCP runtime;
• CAD MCP sleeps until actual CAD demand;
• managed user/runtime state lives under %LOCALAPPDATA%\CadGPT;
• file mutation uses canonical absolute paths inside approved roots;
• production runtime does not self-modify CAD MCP source;
• Revit development is not part of this repository. RevitGPT is maintained as a separate project/repository.

Launch and drawing binding

CadGPT reads the lightweight tray snapshot before starting full CAD MCP.

CG / @cg / @cadgpt
├─ 0 drawings
│  → Welcome screen
│  → WORK IDLE
│
├─ exactly 1 drawing
│  → auto-bind that drawing
│  → Workspace Ready
│
└─ 2+ drawings
   → Welcome screen + drawing list
   → user chooses exactly one
   → Workspace Ready

cg/list refreshes the tray-backed drawing list and does not wake full CAD MCP by itself.

A bound workspace follows:

1 work = 1 drawing

CadGPT never treats ambient AutoCAD ActiveDocument as drawing authority.

Commands

cg/       full command menu
cg/list   refresh open drawings
cg/cl     create or repair Lisp
cg/cj     create or repair Job
cg/job    list registered Jobs
cg/update edit one selected existing Job or Lisp
cg/kug    update global HVAC knowledge (KUG)
cg/kud    update bound-drawing HVAC knowledge (KUD)
cg/mcp    CAD MCP development workflow (development builds only)
cg/help   help
cg/stop   stop current work

@cadgpt / @cg activate CadGPT; they are not the CLI namespace.

HVAC domain Knowledge Updater (KUG / KUD)

The Knowledge Updater stores HVAC workflow/domain knowledge separately from CadGPT internal CAD API, AutoLISP and MCP development knowledge.

• KUG / cg/kug — global reusable HVAC practice in