| name | autocad-mcp |
| description | Automate AutoCAD drawing operations through AutoCAD MCP Pro server (FastMCP 3.0).
86 tools for drawings, entities, layers, blocks, dimensions, analysis, batch ops,
templates, and validation. Dual backends: COM (live AutoCAD) and ezdxf (headless DXF).
Trigger when: (1) User mentions AutoCAD, DXF, DWG, or CAD drawings,
(2) User wants to create/modify engineering drawings programmatically,
(3) Working with tools prefixed drawing_, entity_, layer_, block_, dimension_,
analysis_, view_, system_, template_, or validation_,
(4) User asks about CAD automation, drafting workflows, or MCP server setup.
|
AutoCAD MCP Pro
Contents
Quick Start
Standard workflow for any drawing task:
1. drawing_new() # or drawing_open(path)
2. layer_create(name, color, linetype) # set up layers
3. entity_create_*(...) # draw geometry
4. dimension_*(...) # add dimensions
5. analysis_entity_stats() # verify drawing
6. drawing_save() # persist changes
Use transaction_begin() before complex operations. If something goes wrong, transaction_rollback() reverts all changes since begin.
For batch operations, use entity_batch_create(entities) with a list of entity definitions — handles are returned for each created entity.
Backend Selection
| Environment Variable | Behavior |
|---|
AUTOCAD_MCP_BACKEND=auto | Try COM first, fall back to ezdxf (default) |
AUTOCAD_MCP_BACKEND=com | Force COM — requires running AutoCAD on Windows |
AUTOCAD_MCP_BACKEND=ezdxf | Force ezdxf — headless DXF ops, no AutoCAD needed |
COM-only features: system_run_command, system_run_lisp, view_zoom_extents/window (view ops are no-ops in ezdxf). Screenshots: COM uses Win32 capture, ezdxf uses matplotlib render.
Key Concepts
Entity handles: Hex strings (e.g. "1A2B") returned by all create/copy operations. Required for modify/query operations (entity_get, entity_move, entity_delete, etc.).
Coordinates: Drawing units (mm default). Angles in degrees, counter-clockwise from X axis.
ACI colors: 1–255 = specific colors, 256 = ByLayer, 0 = ByBlock. Common: 1=red, 2=yellow, 3=green, 4=cyan, 5=blue, 6=magenta, 7=white.
Transactions: transaction_begin → operations → transaction_commit or transaction_rollback. ezdxf uses full DXF snapshots; COM uses native undo marks.
Tool Groups
Resources (6): autocad://drawing, autocad://layers, autocad://blocks, autocad://stats, autocad://status, autocad://entities/{layer_name}
Prompt templates (5): prompt_floor_plan, prompt_pid_diagram, prompt_electrical_schematic, prompt_mechanical_drawing, prompt_quick_drawing
Common Workflows
New drawing from scratch: Set up layers first, then draw entities, add dimensions, save.
See workflows.md for step-by-step checklists.
Edit existing DXF: drawing_open → entity_list to find entities → modify/delete → save.
Batch operations: entity_batch_create([{type:"line", ...}, {type:"circle", ...}]) — single call, multiple entities.
Template-based: template_apply_layers("architectural") creates standard layer sets, then add content.
Quality check: validation_check(["empty_layers", "zero_length", "duplicate_entities"]) reports issues.
Security Rules
All file paths pass through validate_path():
- Path traversal blocked (
../ patterns rejected)
ALLOWED_PATHS env restricts accessible directories- Write operations require
allow_write=True
Commands pass through sanitize_command():
- Dangerous patterns blocked: ERASE ALL, DELETE, PURGE, QUIT
- LISP sanitized:
startapp, vl-file-delete, dos_* rejected
- Override:
DANGEROUS_COMMANDS_ENABLED=true
Details: security.md
Architecture
server.py FastMCP 3.0 server (86 tools, 6 resources, 5 prompts)
├── config.py Centralized pydantic-settings configuration
├── security.py Path validation + command sanitization
└── backends/
├── base.py AutoCADBackend ABC + data models
├── ezdxf_backend.py Headless DXF via ezdxf (async via _async wrapper)
└── com_backend.py Live AutoCAD via pywin32 COM (STA single-thread)
Middleware stack: ErrorHandling → AuditLog → Timing → Logging
Adding a new tool: (1) abstract method in base.py → (2) implement in ezdxf_backend.py → (3) implement in com_backend.py → (4) register in server.py with @mcp.tool → (5) test
Details: architecture.md
Troubleshooting
| Error | Solution |
|---|
| "Backend unavailable" | Call drawing_new() or drawing_open(path) first |
| "Entity handle not found" | Use entity_list() to get valid handles |
| "Layer not found" | layer_list() to see existing, layer_create() to add |
| "Path validation failed" | Use absolute paths within ALLOWED_PATHS |
| "Command rejected" | Check DANGEROUS_COMMANDS_ENABLED setting |
| "COM backend failed" | Verify AutoCAD is running, or switch to ezdxf |
| "View ops are no-ops" | View/zoom only work with COM backend |
Full list: troubleshooting.md
Examples
Utility Scripts
Setup check: python scripts/check_setup.py — Verify dependencies and configuration
Drawing validation: python scripts/validate_drawing.py — Check for common drawing issues
