LogixDesigner-MCP

MCP server wrapping the Rockwell Automation Logix Designer SDK (Studio 5000) as typed MCP tools, bridged from Windows to Linux via Cloudflare Tunnel.

A Hermes Agent can open ACD files, export to L5K/L5X, read rung logic, enumerate tags and program structure, run verification — all over a typed MCP interface — without ever touching Studio 5000's GUI.

Architecture

Linux (Hermes) ── SSE/HTTPS ──→ Cloudflare Tunnel ──→ Windows
                                                          │
                                              FastMCP ── pythonnet ── Logix Designer SDK
                                              localhost:8765

The Linux side runs mock-based tests; all COM-dependent logic lives on the Windows deployment.

Tools

Tool	Description
get_sdk_info	SDK version, license status, availability
open_project(path)	Open an ACD — returns controller name/type/revision
close_project	Close the current project
project_status	Is a project open? Which one?
save_acd(path)	Save the open project as ACD
export_l5k(path)	Export to L5K text format
export_l5x(path)	Export to L5X XML format
import_l5k(path)	Import an L5K (create ACD from text)
get_controller_tags(scope?)	List controller/program-scope tags
get_program_structure	Programs → routines → rung counts
get_rung_logic(program, routine)	Rung-by-rung ladder text
get_task_structure	Controller task configuration
verify	Run controller verification
restart_host	Restart the SDK COM host

All tools that can fail return structured SdkError — no raw tracebacks.

Development (Linux)

python -m venv .venv
.venv/bin/pip install -e ".[dev]"
.venv/bin/pytest tests/ -v

Deployment (Windows)

See deploy/README.md. Requires:

• Windows Server with Studio 5000 v33+
• Logix Designer SDK installed
• Python 3.11+
• Cloudflare Tunnel (cloudflared)

deploy/install.bat        # Create venv, discover SDK, verify
deploy/cloudflared-config.yml   # Tunnel setup guide
deploy/hermes-config.yaml       # Hermes MCP client config

Project status

• [x] Phase 0: Project skeleton
• [x] Phase 1: Pydantic models, abstract SDK interface, mock implementation (Linux tested)
• [x] Phase 2: FastMCP server with 14 tools, error contract, async wrappers
• [x] Phase 3: Windows deployment artifacts
• [ ] Phase 4: Real COM interop (RealSdkInterop) — requires Windows