tia-harness — Siemens TIA Portal V21 automation (Claude Code plugin)

A Claude Code plugin that drives Siemens TIA Portal V21 through the tia MCP server:
it turns a structured engineering spec into a compliant-by-construction, verifiable TIA
project and stops at the human gates for anything that touches the controller. This plugin
is the open client layer; the TIA Openness serve / API it talks to is a separate product.

How it fits together

Three pieces, split by what runs where:

• tia-harness (this plugin, MIT) — the client: skills + subagents that reason
  about the project and drive the tools, inside Claude Code.
• @renanlido/tia-openness-mcp (npm, MIT) — the bridge the plugin auto-registers
  (npx -y @renanlido/tia-openness-mcp): a thin MCP→HTTP client, no Openness/net48 itself.
• TIA Openness serve / API (separate product) — the engine on a Windows host with
  TIA Portal V21, activated by a license. Without it, the MCP can only diagnose connectivity.

The plugin and the MCP are open and free; the serve is what actually talks to TIA Portal.

Install

/plugin marketplace add renanlido/tia-harness
/plugin install tia-harness@tia-openness
/reload-plugins

That registers the plugin (skills + subagents) and the bundled tia MCP server, which runs
npx -y @renanlido/tia-openness-mcp.

Requirements

• Claude Code (the plugin runtime).
• Node.js 20+ on PATH (for the tia MCP via npx).
• For the MCP-backed skills: a reachable TIA Openness serve host with a valid activation
  license. Point the MCP at it with TIA_API_BASE (default http://localhost:5000; use the
  host/VM IP if it runs elsewhere). The offline skills spec.validate and cpu.select need
  none of this.

Optional env overrides (defaults are built into the MCP, so you usually set none):
TIA_API_TIMEOUT_MS (15000), TIA_SLOW_TIMEOUT_MS (120000), TIA_CONNECT_TIMEOUT_MS (30000).

Skills

Subagents

tia-engineer (offline authoring), hardware-architect (CPU / modules / network),
verifier (verification ladder), safety-reviewer (read-only functional-safety review).

How to use

1. Describe the machine/line, or hand the agent a project-spec (JSON). Run spec.validate
   (and cpu.select for the CPU) — both work offline.
2. With a TIA project open via the MCP, spec.plan previews the build, tia.scaffold builds
   it, tia.verify compiles/checks it.
3. To deploy, tia.handoff prepares the gated download/online step for a human to approve
   — the plugin never downloads, goes online, or authors safety logic on its own.

Safety posture (gates vs guards)

The harness is an assistant up to the gate, never an autonomous commissioner:

• Gates (human-only): first-connect trust dialog · download / CPU-STOP · go-online /
  network scan · master-secret / UMAC · functional safety (F) — never autonomous.
• Guards (automatic): compile-clean before deploy · plan-then-apply (dry-run) · idempotency
  by name · OrderNumber:<MLFB>/V<fw> format · serial-only tool calls · untrusted-input
  (a spec never auto-crosses a gate).

Other AI clients (Codex, Gemini CLI, Cursor, VS Code, …)

The tia MCP works in any MCP client, not just Claude Code — it's the same npx package. The
canonical, copy-paste install of the MCP for Claude Code, Claude Desktop, Codex (CLI/IDE),
Gemini CLI, Cursor, VS Code, and Windsurf (with the Windows cmd /c npx and the VS Code servers
gotchas) is in docs/INSTALL.md.

The harness (skills + subagents) installs differently per client. Claude Code uses the
marketplace above. Codex and Gemini CLI have no plugin marketplace, so you install the
harness by copying the ported files into their config folders. First clone this repo:

git clone https://github.com/renanlido/tia-harness.git
cd tia-harness

Codex (CLI + IDE)

mkdir -p ~/.codex/agents ~/.agents/skills
cp    codex/agents/*.toml  ~/.codex/agents/     # subagents
cp -r codex/skills/*       ~/.agents/skills/    # skills
cp    codex/AGENTS.md      ~/.codex/AGENTS.md    # operating guide (or copy to a repo root)

Then wire the tia MCP in ~/.codex/config.toml — see docs/INSTALL.md →
Codex. Full detail: codex/README.md.

Gemini CLI

mkdir -p ~/.gemini/agents ~/.gemini/commands
cp gemini/agents/*.md      ~/.gemini/agents/     # subagents
cp gemini/commands/*.toml  ~/.gemini/commands/   # the 8 skills, as custom commands
cp gemini/GEMINI.md        ~/.gemini/GEMINI.md    # operating guide (or copy to a repo root)

Then wire the tia MCP in ~/.gemini/settings.json — see docs/INSTALL.md →
Gemini CLI. Note: Gemini has no skill auto-trigger, so you invoke the skills explicitly as
slash commands: /spec-validate, /cpu-select, /spec-plan, /tia-review, /tia-scaffold,
/tia-verify, /tia-handoff, /tia-init. Full detail: gemini/README.md.

Windows (PowerShell) instead of cp: use Copy-Item codex\agents\*.toml $env:USERPROFILE\.codex\agents\ (add -Recurse for the skills folder) — see the per-port
READMEs for the exact PowerShell commands.

The Claude Code plugin is the reference; its operating guide
(.claude-plugin/CLAUDE.md) is the canonical source the Codex/Gemini guides mirror.

Related

MCP server on npm: @renanlido/tia-openness-mcp (npx -y @renanlido/tia-openness-mcp).

License

MIT — see LICENSE. This plugin is the open client layer; the TIA Openness
serve / API it talks to is a separate, proprietary product.