festo-codesys-mcp: Command for Claude Code

.claude/commands/fb-from-library.md

fb-from-library is a command for Claude Code from efranceschetti/festo-codesys-mcp. It costs 36 tokens per session (393 once invoked), scanned A, original, MIT.

A guided process for copying a Function Block, a reusable unit of PLC control logic, from a library into a project. It shows the source, collects naming and connection details, validates the interface, and saves the adapted file.

In plain words
What is it for?
Use it to adapt a library Function Block, rename its types or instances, document real input and output connections, and save it under the project’s source directory.
Why use it?
It reduces repetitive copying and customization while preserving the original state-machine logic. Validation helps catch interface problems before the block is imported.

Command for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: positional $N argument.

This is efranceschetti/festo-codesys-mcp's own configuration. It tells Claude Code how to work on festo-codesys-mcp itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything festo-codesys-mcp configures →

Reuse

Borrowing it

Nothing to install: this file belongs to efranceschetti/festo-codesys-mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/efranceschetti/festo-codesys-mcp/main/.claude/commands/fb-from-library.md
Clone the repo
git clone --depth 1 https://github.com/efranceschetti/festo-codesys-mcp

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for fb-from-library

README.md
[![agentmods](https://agentmods.dev/badge/commands/efranceschetti/festo-codesys-mcp/fb-from-library/github.svg)](https://agentmods.dev/commands/efranceschetti/festo-codesys-mcp/fb-from-library)
Your own site
<a href="https://agentmods.dev/commands/efranceschetti/festo-codesys-mcp/fb-from-library"><img src="https://agentmods.dev/badge/commands/efranceschetti/festo-codesys-mcp/fb-from-library/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for fb-from-library

Your own site · 80×15
<a href="https://agentmods.dev/commands/efranceschetti/festo-codesys-mcp/fb-from-library"><img src="https://agentmods.dev/badge/commands/efranceschetti/festo-codesys-mcp/fb-from-library.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 36 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 393 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00036 $0.00393
Opus 5 $0.00018 $0.00197
Sonnet 5 $0.00007 $0.00079
Haiku 4.5 $0.00004 $0.00039

Measured 8d ago against content hash 194e0f111d35, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

fb-from-library 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 8d ago.

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.

.claude/commands/fb-from-library.md · 27 lines

What it actually says

Adapt a library FB into the project. Arguments: FB name + (optional) destination folder.

Sequence

  1. Identify the sourceplc_library action=get with name=$1. If not found, suggest plc_library action=search.
  2. Show the source — display the full FB content to the user with a short explanation (1-2 lines) of what it does.
  3. Collect customizations — ask the user (single round):
    • Name in the project (default: same name)
    • Specific types/instances to rename
    • Real I/O ports that will connect (to place as a comment in the header)
  4. Adapt — generate a customized version with:
    • A personalized header (author, date, machine, target instance)
    • The requested renames
    • Extra comments on the VAR_INPUT/OUTPUT mapping to the real I/O
    • PRESERVE the CASE nState logic and the state machine — do not invent
  5. Validateplc_validate action=fb_interface on the result.
  6. SaveWrite to the destination (default: src/pou/<name>.st).
  7. Report — the saved path + next steps (generate XML, import).

NEVER add logic that was not in the original FB. NEVER break the state machine. Renaming/customizing is mechanical, not inventive.

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. 8d ago First seen · 27 lines · 36 tokens per session scan A 194e0f111d35

Subscribe to this mod's changes

fb-from-library is a command published in the GitHub repository efranceschetti/festo-codesys-mcp (1 stars, last pushed 3d ago), licensed MIT. It adds 36 tokens to every session and 393 once invoked, about $0.0002 per session on Opus 5. 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.