Tia Harness

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

| Skill | What it does | Needs the MCP? | |---|---|---| | spec.validate | validate a project-spec vs the JSON Schema + engineering rules (incl. the G5 safety rule) | no — offline | | cpu.select | recommend an S7-1500 / S7-1200 CPU + order number (MLFB) from requirements | no — offline | | spec.plan | a valid spec → the ordered, dry build plan (nothing applied) | no — pure | | tia.review | audit an open project vs the baseline (optimized access, symbolic, UDT, naming) | read-only | | tia.scaffold | build a project from a spec (devices → network → tags → blocks → compile) | yes | | tia.verify | the verification ladder (compile / consistency / export) | yes | | tia.handoff | prepare the human-approval envelope for the download / online / safety gates | yes (gate) |

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.

1. With a TIA project open via the MCP, spec.plan previews the build, tia.scaffold builds

it, tia.verify compiles/checks it.

1. 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:/V 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](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](docs/INSTALL.md) → Codex. Full detail: [codex/README.md](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](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](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](.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](LICENSE). This plugin is the open client layer; the TIA Openness serve / API it talks to is a separate, proprietary product.

Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: renanlido
• Source: renanlido/tia-harness
• License: MIT

Install and usage instructions live in the source repository linked above.