katgpt-rs: Skill for Claude Code

.agents/skills/boundary-guard/SKILL.md

boundary-guard is a skill for Claude Code, Codex from katopz/katgpt-rs. It costs 155 tokens per session (8,867 once invoked), scanned A, original, MIT.

A code-review tool for checking that parts of a game stay within their assigned responsibilities across several code repositories. It compares the code with each repository’s written boundary rules.

In plain words
What is it for?
Use it when adding or reviewing game systems, game logic, vocabulary types, low-level interfaces, or view code. It can also be used for regular workspace-wide boundary checks.
Why use it?
It helps catch game logic placed in the wrong layer, incorrect dependencies between repositories, and outdated or unsupported boundary rules.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents); mentions AGENTS.md.

This is katopz/katgpt-rs's own configuration. It tells Claude Code and Codex how to work on katgpt-rs 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 katgpt-rs configures →

Needs its repository: it runs a file that does not travel with it, so clone the repository first. The line is cd riir-ai && ./scripts/ci_boundary_contract.sh # exit 0 = clean.

Reuse

Borrowing it

Nothing to install: this file belongs to katopz/katgpt-rs. 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/katopz/katgpt-rs/develop/.agents/skills/boundary-guard/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/katopz/katgpt-rs

Made for: Claude Code, Codex.

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 boundary-guard

README.md
[![agentmods](https://agentmods.dev/badge/skills/katopz/katgpt-rs/boundary-guard/github.svg)](https://agentmods.dev/skills/katopz/katgpt-rs/boundary-guard)
Your own site
<a href="https://agentmods.dev/skills/katopz/katgpt-rs/boundary-guard"><img src="https://agentmods.dev/badge/skills/katopz/katgpt-rs/boundary-guard/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 boundary-guard

Your own site · 80×15
<a href="https://agentmods.dev/skills/katopz/katgpt-rs/boundary-guard"><img src="https://agentmods.dev/badge/skills/katopz/katgpt-rs/boundary-guard.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 155 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 8,867 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 $0.00155 $0.08867
Opus 5 $0.00077 $0.04433
Sonnet 5 $0.00031 $0.01773
Haiku 4.5 $0.00015 $0.00887

Measured today against content hash a89053717b30, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

boundary-guard 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 today.

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.

.agents/skills/boundary-guard/SKILL.md · 209 lines

How it starts

The opening of the file, as written. The whole thing — 209 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Boundary Guard

Generic game logic → substrate (riir-games). View renders state, doesn't compute it. FFI moves raw bytes only.

Spec source — each repo's BOUNDARY.md

Every repo ships a root BOUNDARY.md — the per-repo contract this skill audits against: Owns / Does not own / May depend on (crate-granular allowlist with Location) / Inherited (links) / Drift ledger. The 8-surface table below is the workspace methodology; the per-repo rules + exceptions come from that repo's BOUNDARY.md, not from this file's prose. Findings are therefore two classes: code-vs-contract violations and contract rot (drift row without an open issue, allowlist row without a gate, by-design row whose decision record is gone).

Two scripts, one job each (added 2026-08-21, Issue 737 T-CI/T-GATE):

script scope question it answers
riir-ai/scripts/ci_boundary_contract.sh workspace (every repo with a root BOUNDARY.md18 at the 2026-09-01 run; the script enumerates, so prefer its banner over this cell) Is the dep graph what the contracts say — and are the contracts still honest? Parses every May depend on table + drift ledger, checks the riir-ai CANONICAL matrix against the measured graph, pins the 4 split-prep invariants. --list-deps prints the measured edge set; --repo X narrows.
riir-mmorpg-examples/scripts/ci_boundary_guard.sh that repo's src/ Is the CODE in the right repo? Checks A–E: System impls with game logic, duplicated geometry, hardcoded behavior constants, generic logic in free functions, facade leaks.

The contract script replaces prose-only allowlists; it is the successor of Issue 724 Phase 2's "document the contract and review by hand". EXEMPT_LEAKS in the per-repo guard deliberately STAYS file-granular — the ledger is surface-granular, and collapsing the two would lose the file:line precision Check E needs.

Drift-ledger semantics (scripts consume this): Disposition ∈ fixable | owner-call | by-design. fixable/owner-call rows REQUIRE an open issue; by-design rows cite a decision record instead. Issue closes → row removed in the same commit. Exit semantics: ledger unparseable → hard error; finding mapped to a row → exit 0 with a LOUD known-drift count; unmapped finding → exit 1; row-without-open-issue → exit 1 (rot). Never silently fail open or closed.

Read the full file on GitHub · 209 lines

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. today Changed · +14 lines a89053717b30
  2. yesterday Changed · -1 lines d8c20c5456e2
  3. 3d ago Changed · +3 lines 4426af51cfb9
  4. 4d ago Changed · +8 lines dcfc8527795d
  5. 5d ago Changed · +4 lines 759af6d51ae2
  6. 6d ago Changed · +37 lines · +9 tokens per session 199996f5b79b
  7. 11d ago First seen · 144 lines · 146 tokens per session scan A 778454af62e0

Subscribe to this mod's changes

boundary-guard is a skill published in the GitHub repository katopz/katgpt-rs (98 stars, last pushed today), licensed MIT. It adds 155 tokens to every session and 8,867 once invoked, about $0.0008 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 2026-08-30.

Related

Other skills, from other repositories

animation-review

Reviews Godot Animation implementation for known pitfalls. Triggers AFTER implementation, when code involves AnimationPlayer, AnimationTree, AnimatedSprite2D, SpriteFrames, AnimationNodeStateMachine, BlendSpace, OneShot, callbackmodeprocess, or animation playback control (play/travel/start). Do NOT use this skill for…

valkor-ai/loom · 75 tokens

tilemap-review

Reviews Godot TileMap implementation for known pitfalls. Triggers AFTER implementation, when code involves TileMapLayer, TileSet, TileSetAtlasSource, TileSetScenesCollectionSource, terrain painting, setcell, erasecell, getcelltiledata, collision polygons on tiles, or NavigationRegion2D with tile-based navigation. Do…

valkor-ai/loom · 85 tokens

godot-code-review

Use when reviewing GDScript or C# Godot code — checklist of best practices, common anti-patterns, and Godot-specific pitfalls.

jame581/GodotPrompter · 33 tokens

hz-unity-code-review

Reviews Unity code targeting Meta Quest and Horizon OS for performance issues, rendering best practices, and common VR pitfalls. Use during code review or when diagnosing Quest performance problems in Unity projects.

meta-quest/agentic-tools · 42 tokens

unity-reviewer

Use when reviewing Unity C# code changes — checks for runtime-breaking bugs, performance anti-patterns, and maintainability issues. Provides severity-tiered review organized as Critical, Performance, and Style.

TheArcForge/Hades · 39 tokens

design-lenses

Structured game-design critique: review a game through Schell's design lenses, Wright's systems-and-emergence lenses, and the MDA framework, producing severity-ranked findings with concrete fixes. Use when the user asks 'is my game fun?', 'review my game design', 'why is it boring?', 'critique this game', 'what's…

kyh/vibedgames · 118 tokens