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.
npx agentmods add skills/slbug/claude-ruby-grape-rails/active-record-patternsnpx skills add slbug/claude-ruby-grape-rails --skill active-record-patternsgit clone --depth 1 https://github.com/slbug/claude-ruby-grape-railsWhat 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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00050 | $0.00390 |
| Opus 5 | $0.00025 | $0.00195 |
| Sonnet 5 | $0.00010 | $0.00078 |
| Haiku 4.5 | $0.00005 | $0.00039 |
Grade A, and why
active-record-patterns 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 2d 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.
What it actually says
Active Record Patterns
Iron Laws
- Use
decimalor integer cents for money. - Prevent N+1 queries with intentional preload strategy.
- Put invariants inside transactions and use locks when races matter.
- Prefer
after_commitfor external side effects. - Keep schema constraints aligned with application validations.
Default Moves
- use foreign keys and indexes deliberately
- choose
includes,preload, oreager_loadintentionally - use
find_eachfor large backfills and batch work - use optimistic or pessimistic locking where correctness depends on it
- make migrations reversible and production-safe
References
| Need | Reference |
|---|---|
| transactions, locking, partial-failure recovery | ${CLAUDE_SKILL_DIR}/references/transactions.md |
validation patterns, update_columns audit trails |
${CLAUDE_SKILL_DIR}/references/validations.md |
| query composition, scopes, subqueries, batched inserts | ${CLAUDE_SKILL_DIR}/references/queries.md |
| production-safe migration recipes | ${CLAUDE_SKILL_DIR}/references/migrations.md |
| PostgreSQL full-text + trigram + hybrid search | ${CLAUDE_SKILL_DIR}/references/fulltext-search.md |
Related — invoke manually if needed
- Sequel ORM (non-Active Record) work →
/rb:sequel-patterns(Sequel ORM patterns)
What ships with it
5 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.
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.
- 2d ago First seen · 40 lines · 50 tokens per session scan A 238de1ed6d0f
active-record-patterns is a skill published in the GitHub repository slbug/claude-ruby-grape-rails (7 stars, last pushed 3d ago), licensed MIT. It adds 50 tokens to every session and 390 once invoked, about $0.0003 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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