rb:n1-check

rb:n1-check is a skill for Claude Code from slbug/claude-ruby-grape-rails. It costs 46 tokens per session (207 once invoked), scanned A, original, MIT.

A checker for N+1 database queries, where code repeatedly fetches related records one at a time instead of efficiently loading them together.

In plain words
What is it for?
It is for inspecting association loops, serializers, and endpoints and choosing between `includes`, `preload`, or `eager_load`.
Why use it?
It helps find a common cause of slow Rails pages and API responses, especially when serializers or nested data are involved.

Skill for Claude Code

Written for Claude Code: argument-hint in frontmatter.

Part of the ruby-grape-rails plugin — 52 skills, 19 agents, 17 hooks shipped together

Good fit It is for inspecting association loops, serializers, and endpoints and choosing between includes, preload, or eager_load.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/slbug/claude-ruby-grape-rails/ar-n1-check
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.

Any agent
npx skills add slbug/claude-ruby-grape-rails --skill ar-n1-check
Clone the repo
git clone --depth 1 https://github.com/slbug/claude-ruby-grape-rails

Made for: Claude Code.

Or install ruby-grape-rails, the plugin that ships this one along with the rest of its 52 skills, 19 agents, 17 hooks.

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 rb:n1-check

README.md
[![agentmods](https://agentmods.dev/badge/skills/slbug/claude-ruby-grape-rails/ar-n1-check.svg)](https://agentmods.dev/skills/slbug/claude-ruby-grape-rails/ar-n1-check)
Your own site
<a href="https://agentmods.dev/skills/slbug/claude-ruby-grape-rails/ar-n1-check"><img src="https://agentmods.dev/badge/skills/slbug/claude-ruby-grape-rails/ar-n1-check.svg" alt="Measured on agentmods" height="20"></a>
Per session 46 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 207 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 $0.00046 $0.00207
Opus 5 $0.00023 $0.00103
Sonnet 5 $0.00009 $0.00041
Haiku 4.5 $0.00005 $0.00021

Measured 7d ago against content hash 83e581f55113, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

rb:n1-check 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 7d 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.

plugins/ruby-grape-rails/skills/ar-n1-check/SKILL.md · 23 lines

What it actually says

N+1 Check

Look for:

  • loops that hit associations lazily
  • serializers/presenters causing repeated loads
  • controller or endpoint code that fetches parents and then children one-by-one
  • missing preload strategy for nested responses
  • places where strict_loading or Bullet-style checks would surface the problem earlier

References

Need Reference
preload / includes / eager_load decision matrix ${CLAUDE_SKILL_DIR}/references/preload-patterns.md
broader query optimization (CTEs, window functions, batched inserts/updates) ${CLAUDE_SKILL_DIR}/references/query-optimization.md
Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 7d ago First seen · 23 lines · 46 tokens per session scan A 83e581f55113

Subscribe to this mod's changes

rb:n1-check is a skill published in the GitHub repository slbug/claude-ruby-grape-rails (7 stars, last pushed 3d ago), licensed MIT. It adds 46 tokens to every session and 207 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.

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