presentation-rule

A set of rules for the presentation layer, the part of an application that receives API requests and sends responses. It covers controllers, request and response conversion, validation boundaries, and error handling for a Go gRPC service.

In plain words
What is it for?
Use it when adding or changing API endpoints, controllers, middleware, request conversions, or gRPC error responses.
Why use it?
It keeps API-facing code focused on translating data and calling application logic, instead of mixing it with business rules or database work.

Cursor rule for Cursor

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.

agentmods
npx agentmods add rules/showcase-gig-platform/cursor-rules-initializer/presentation-rule
Clone the repo
git clone --depth 1 https://github.com/showcase-gig-platform/cursor-rules-initializer

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 450 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00000 $0.00450
Opus 5 $0.00000 $0.00225
Sonnet 5 $0.00000 $0.00090
Haiku 4.5 $0.00000 $0.00045

Measured 2d ago against content hash 9c73d0030732, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

presentation-rule 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.

.cursor/commands/cursor-rules-initializer/sample/rules/app/presentation-rule.mdc · 41 lines

What it actually says

presentation層の修正をする際に適用するルール

役割

  • API エンドポイントの定義
  • リクエスト/レスポンスの変換
  • ユースケースの呼び出し
  • バリデーション
  • エラーハンドリング

詳細構造と命名規則

presentation/
├── controller/                 # コントローラー
│   └── api/                    # API実装
│       ├── user_controller.go  # Userコントローラー
│       └── order_controller.go # Orderコントローラー
├── middleware/                 # ミドルウェア
│   ├── auth.go                 # 認証ミドルウェア
│   └── logging.go              # ロギングミドルウェア
└── error/                      # エラーハンドリング
    └── converter.go            # エラー変換

実装ポイント

  • コントローラーはユースケースを呼び出すだけで、ビジネスロジックは含みません
  • プロトコルバッファからリクエストへの変換を適切に行います
    • validationはusecase層の役割なので、コントローラーではusecaseが要求するinputへの変換だけを行います
  • ユースケース呼び出し後のエラーを適切にハンドリングします
    • エラーはgRPCステータスコードに変換して返却します
  • プロトコルバッファとDTOの変換を行います

実装例

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. 2d ago First seen · 41 lines · 0 tokens per session scan A 9c73d0030732

Subscribe to this mod's changes

presentation-rule is a cursor rule published in the GitHub repository showcase-gig-platform/cursor-rules-initializer (7 stars, last pushed 9mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 450 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.