tckit

An MCP server and skill set for TwinCAT 3 programmable-logic-controller projects. It can read project structure, edit Structured Text code, build, deploy, and run TcUnit tests.

In plain words
What is it for?
Use it to inspect TwinCAT projects, write PLC code, trigger builds, deploy to controllers, and run TcUnit tests.
Why use it?
It gives a coding agent a defined way to work with industrial-control projects and their tests and deployment targets.

Plugin for Claude Code

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Claude Code
/plugin marketplace add georgeturneruk/tckit
agentmods
npx agentmods add plugins/georgeturneruk/tckit/plugin
Clone the repo
git clone --depth 1 https://github.com/georgeturneruk/tckit

Made for: Claude Code.

Per session not measured What this adds to a session before it is invoked.
When invoked not measured Not applicable: nothing here is loaded into a session.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Security

Grade A, and why

tckit scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugin/.claude-plugin/plugin.json · 23 lines

What it actually says

{
  "name": "tckit",
  "version": "0.6.0",
  "description": "MCP server for TwinCAT 3 PLC projects: read structure, write ST code, trigger builds, deploy to targets, run TcUnit tests.",
  "author": {
    "name": "George Turner",
    "url": "https://georgeturner.uk"
  },
  "homepage": "https://tckit.org",
  "repository": "https://github.com/georgeturneruk/tckit",
  "license": "MIT",
  "keywords": [
    "twincat",
    "plc",
    "mcp",
    "beckhoff",
    "structured-text",
    "automation"
  ],
  "mcpServers": "./.mcp.json",
  "skills": "./skills/"
}
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 23 lines scan A 778013885c58

Subscribe to this mod's changes

tckit is a plugin published in the GitHub repository georgeturneruk/tckit (5 stars, last pushed 7d ago), licensed MIT. Its token cost is not measured: this kind of file is read by the harness, not the model. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.