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.
git clone --depth 1 https://github.com/muraaano/cursor-project-rules-on-railsWrote 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.
[](https://agentmods.dev/rules/muraaano/cursor-project-rules-on-rails/models)<a href="https://agentmods.dev/rules/muraaano/cursor-project-rules-on-rails/models"><img src="https://agentmods.dev/badge/rules/muraaano/cursor-project-rules-on-rails/models/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.
<a href="https://agentmods.dev/rules/muraaano/cursor-project-rules-on-rails/models"><img src="https://agentmods.dev/badge/rules/muraaano/cursor-project-rules-on-rails/models.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00000 | $0.00433 |
| Opus 5.5 | $0.00000 | $0.00173 |
| Sonnet 5.5 | $0.00000 | $0.00087 |
| Haiku 4.5 | $0.00000 | $0.00043 |
Grade A, and why
models 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 2mo 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
Modelの実装規約
基本方針
- アプリケーションのドメインロジックを扱う処理は、Modelに実装する
- Modelは
app/modelsに配置する - ファイル名はクラス名のスネークケースとする
- データベースアクセスするテーブルがある場合は、RailsのActiveRecord(実際にはApplicationRecord)を継承したクラスとする
- テーブルがない場合は、PORO（Pure Old Ruby Object）かイベント型モデルを選択する
- 複数のモデルに関連した一連のイベントをまとめる場合は、イベント型モデルとする
- イベントではない場合は、PORO（特に継承をしないクラス）とする
- validationが不要な場合で、イベント型モデルにする理由がない場合はPOROを採用する。
- I/Fが簡素化でき、メモリなどのコストも低いため。
イベント型モデル
ApplicationEventModelを継承して作成する- クラス名は、イベント名の名詞とし、末尾に
Eventをつける- 例：
MoveEvent
- 例：
- I/FはRailsのApplicationModelに準ずる（https://railsguides.jp/active_model_basics.html）
- 例：
valid?,save
- 例：
validation
- カスタムvalidatorの実装はなるべく控え、既存のvalidator(numericalityなど)を使う
トランザクション
-
データの整合性を保つために、関連するデータの更新は必ずトランザクション内で行う
ApplicationRecord.transaction do # データの更新処理 end
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.
- 2mo ago First seen · 42 lines · 0 tokens per session scan A 2f01d6d4edf8
models is a cursor rule published in the GitHub repository muraaano/cursor-project-rules-on-rails (2 stars, last pushed 1y ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 433 tokens. 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.
Other cursor rules, from other repositories
api-property-optionality-hygiene
Fix ApiProperty/ApiPropertyOptional optionality mismatches in DTO files; use for scheduled batch fixes or DTO edits.
python
Python best practices and patterns for modern software development with Flask and SQLite.
cursor
You are working on the checkout service. Preserve transaction integrity and auditability.
django
Definitive guidelines for writing maintainable, performant, and secure Django applications, emphasizing modern best practices, clear code organization, and efficient patterns.
selectools-providers
Rules for working with LLM provider adapters in selectools.
ehs-ims-conventions
EHS IMS app — RBAC, data layer, tRPC, migrations, AI boundaries.