exception

A generator for application error handling, including domain-specific exceptions and one central handler for turning errors into structured HTTP responses.

In plain words
What is it for?
Use it to create a not-found exception and configure a global Spring handler that returns the Problem Details format, a standard structure for HTTP error responses.
Why use it?
It gives clients consistent error details and keeps error processing out of individual controllers.

Skill for Claude CodeCodex

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 skills/demodev-lab/claude-code-plugin-demokit/exception
Any agent
npx skills add demodev-lab/claude-code-plugin-demokit --skill exception
Clone the repo
git clone --depth 1 https://github.com/demodev-lab/claude-code-plugin-demokit

Made for: Claude Code, Codex.

Per session 41 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 318 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 $0.00041 $0.00318
Opus 5 $0.00020 $0.00159
Sonnet 5 $0.00008 $0.00064
Haiku 4.5 $0.00004 $0.00032

Measured 2d ago against content hash 209059481a5b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

exception 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.

skills/exception/SKILL.md · 45 lines

What it actually says

/exception - 예외 처리 설정

help

인자가 help이면 아래 도움말만 출력하고 실행을 중단한다:

/exception — 도메인 예외 및 GlobalExceptionHandler 생성

사용법:
  /exception {Name}

파라미터:
  Name  PascalCase 도메인명 (필수)

예시:
  /exception User
  /exception Order

관련 명령:
  /crud   — CRUD 일괄 생성
  /entity — JPA Entity 생성

실행 절차

  1. 도메인 예외 생성: domain/{name}/exception/{Name}NotFoundException.java
    • RuntimeException 상속
    • String.formatted() 메시지
  2. GlobalExceptionHandler (없으면 생성):
    • common/exception/GlobalExceptionHandler.java
    • @RestControllerAdvice extends ResponseEntityExceptionHandler
    • ProblemDetail (RFC 9457) 기반
    • 4xx → warn 로그, 5xx → error 로그
  3. ProblemDetail 활성화 안내: spring.mvc.problemdetails.enabled=true

관련 Agent

  • api-expert

관련 템플릿

  • templates/code/exception.template.java
Files

What ships with it

1 file 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. 2d ago First seen · 45 lines · 41 tokens per session scan A 209059481a5b

Subscribe to this mod's changes

exception is a skill published in the GitHub repository demodev-lab/claude-code-plugin-demokit (2 stars, last pushed 6mo ago), licensed MIT. It adds 41 tokens to every session and 318 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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