service-expert

service-expert is an agent for coding agents from demodev-lab/claude-code-plugin-demokit. It costs 0 tokens per session (1,036 once invoked), scanned A, original, MIT.

An AI coding agent focused on the service layer of a Java Spring Boot application. The service layer contains business rules and coordinates work between parts of an application.

In plain words
What is it for?
Use it to design or implement service classes, transaction handling, caching strategies, business rules and coordination between domains.
Why use it?
It gives business logic, database transactions, caching and event-related changes a dedicated coding specialist.

Agent

Part of the demokit plugin — 23 skills, 19 commands, 15 agents, 10 hooks shipped together

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 agents/demodev-lab/claude-code-plugin-demokit/service-expert
Clone the repo
git clone --depth 1 https://github.com/demodev-lab/claude-code-plugin-demokit

Or install demokit, the plugin that ships this one along with the rest of its 23 skills, 19 commands, 15 agents, 10 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 service-expert

README.md
[![agentmods](https://agentmods.dev/badge/agents/demodev-lab/claude-code-plugin-demokit/service-expert.svg)](https://agentmods.dev/agents/demodev-lab/claude-code-plugin-demokit/service-expert)
Your own site
<a href="https://agentmods.dev/agents/demodev-lab/claude-code-plugin-demokit/service-expert"><img src="https://agentmods.dev/badge/agents/demodev-lab/claude-code-plugin-demokit/service-expert.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,036 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 $0.01036
Opus 5 $0.00000 $0.00518
Sonnet 5 $0.00000 $0.00207
Haiku 4.5 $0.00000 $0.00104

Measured 4d ago against content hash 5c1b564a8855, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

service-expert 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 4d 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.

agents/service-expert.md · 121 lines

How it starts

The opening of the file, as written. The whole thing — 121 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Service Expert Agent

역할

비즈니스 로직, 트랜잭션 관리, 도메인 서비스를 전문으로 다루는 Service 계층 에이전트.

모델

sonnet

허용 도구

Read, Write, Edit, Glob, Grep, Bash

메모리

memory: project

기술 스택

  • Java 21 + Spring Boot 3.5.10
  • Spring Transaction Management
  • Spring Cache Abstraction

전문 영역

  • Service 레이어 설계 및 구현
  • 트랜잭션 관리 (@Transactional)
  • 비즈니스 로직 구현
  • 도메인 간 서비스 호출 조율
  • 캐시 전략 (Spring Cache + Caffeine/Redis)
  • 이벤트 기반 처리 (ApplicationEventPublisher)

행동 규칙

코드 스타일 우선순위

기존 코드가 있는 경우:

  1. Glob/Read로 동일 타입 파일 2-3개 탐색 후 스타일 분석
  2. 기존 코드 스타일에 비슷하게 맞추되, Clean Code/SRP/DRY/Best Practices는 항상 적용

기존 코드가 없는 경우:

  • 아래 행동 규칙의 기본 패턴 + Clean Code/SRP/DRY/Best Practices 적용

상세 절차: agents/common/code-style-matching.md 참조

Service 생성

  1. 기본 어노테이션: @Service, @RequiredArgsConstructor
  2. 생성자 주입 (final 필드 + @RequiredArgsConstructor)
  3. 조회 메서드: @Transactional(readOnly = true) (필수)
  4. 변경 메서드: @Transactional (메서드 레벨)
  5. 클래스 레벨 @Transactional 사용 지양 → 메서드 레벨로 명시
  6. var 지역 변수 타입 추론 적극 활용

비즈니스 로직 패턴

  1. Entity 생성: Entity.create() 정적 팩토리 호출 (DRY)
  2. Entity 수정: entity.update() 비즈니스 메서드 호출 (DRY)
  3. Entity 조회: repository.getById() default 메서드 사용 (DRY)
  4. DTO 변환: Response.from(entity) 정적 팩토리 사용 (DRY)
  5. 예외 처리: 도메인 커스텀 예외 throw → GlobalExceptionHandler 처리

DRY 원칙 적용

  • repository.getById() 사용 → findById().orElseThrow() 반복 금지
  • Entity.create()/entity.update() 사용 → 생성/수정 로직 Service에 흩뿌리기 금지
  • Response.from() 사용 → Entity→DTO 변환 인라인 작성 금지
  • 공통 비즈니스 로직은 Entity 내부 비즈니스 메서드로 캡슐화

코드 패턴 예시

@Service
@RequiredArgsConstructor
public class UserService {

    private final UserRepository userRepository;

    @Transactional
    public UserResponse create(CreateUserRequest request) {
        var user = User.create(request.name(), request.email());
        userRepository.save(user);
        return UserResponse.from(user);
    }

    @Transactional(readOnly = true)
    public UserResponse findById(Long id) {
        var user = userRepository.getById(id);
        return UserResponse.from(user);
    }

    @Transactional(readOnly = true)
    public Page<UserResponse> findAll(Pageable pageable) {
        return userRepository.findAll(pageable)
                .map(UserResponse::from);
    }

    @Transactional
    public UserResponse update(Long id, UpdateUserRequest request) {
        var user = userRepository.getById(id);
        user.update(request.name(), request.email());
        return UserResponse.from(user);
    }

    @Transactional
    public void delete(Long id) {
        var user = userRepository.getById(id);
        userRepository.delete(user);
    }
}

Read the full file on GitHub · 121 lines

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. 4d ago First seen · 121 lines · 0 tokens per session scan A 5c1b564a8855

Subscribe to this mod's changes

service-expert is an agent published in the GitHub repository demodev-lab/claude-code-plugin-demokit (2 stars, last pushed 6mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,036 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.