seoul-opendata-mcp: Instructions file for Claude Code

CLAUDE.md

seoul-opendata-mcp CLAUDE.md is an instructions file for Claude Code from whchoi98/seoul-opendata-mcp. It costs 913 tokens per session, scanned A, original, MIT.

Project-specific instructions for working on a TypeScript server that provides Seoul city data through tools an AI assistant can call.

In plain words
What is it for?
Use them when building, testing, inspecting, or packaging the Seoul Open Data MCP server.
Why use it?
They give contributors the project context, file layout, commands, and coding rules in one place.

Instructions file for Claude Code

Written for Claude Code: the file is CLAUDE.md. Also seen: mentions CLAUDE.md.

This is whchoi98/seoul-opendata-mcp's own configuration. It tells Claude Code how to work on seoul-opendata-mcp itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything seoul-opendata-mcp configures →

Reuse

Borrowing it

Nothing to install: this file belongs to whchoi98/seoul-opendata-mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/whchoi98/seoul-opendata-mcp/main/CLAUDE.md
Clone the repo
git clone --depth 1 https://github.com/whchoi98/seoul-opendata-mcp

Made for: Claude Code.

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 seoul-opendata-mcp CLAUDE.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/whchoi98/seoul-opendata-mcp/claude-md/github.svg)](https://agentmods.dev/instructions/whchoi98/seoul-opendata-mcp/claude-md)
Your own site
<a href="https://agentmods.dev/instructions/whchoi98/seoul-opendata-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/whchoi98/seoul-opendata-mcp/claude-md/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.

agentmods 80×15 button for seoul-opendata-mcp CLAUDE.md

Your own site · 80×15
<a href="https://agentmods.dev/instructions/whchoi98/seoul-opendata-mcp/claude-md"><img src="https://agentmods.dev/badge/instructions/whchoi98/seoul-opendata-mcp/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 913 This file is loaded in full into every session.
When invoked 913 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00913 $0.00913
Opus 5 $0.00456 $0.00456
Sonnet 5 $0.00183 $0.00183
Haiku 4.5 $0.00091 $0.00091

Measured 11d ago against content hash 13741f1d17bc, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

seoul-opendata-mcp CLAUDE.md 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 11d 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.

CLAUDE.md · 50 lines

How it starts

The opening of the file, as written. The whole thing — 50 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Project Context

Overview

seoul-opendata-mcp(v0.3.0, MIT)는 서울 열린데이터광장(Seoul Open Data Plaza) 실시간 도시데이터를 19개 MCP tool로 stdio를 통해 제공하는 MCP 서버입니다. GitHub: https://github.com/whchoi98/seoul-opendata-mcp.

Tech Stack

  • TypeScript(strict, ESM), Node.js >=18
  • @modelcontextprotocol/sdk(stdio transport), zod(입력 스키마 검증), fast-xml-parser(XML 폴백 파싱)
  • vitest(단위 테스트 + 선택적 live-smoke 테스트)

Project Structure

src/client/     HTTP 클라이언트: 키 폴백, TTL 캐시, 페이지네이션, 재시도, XML 폴백, .env 로더
src/normalize/  봉투(envelope) unwrap + 도메인별 필드 정규화
src/tools/      MCP tool 19개: 도메인 register 5개 파일 + meta/stats/health
src/data/       핫스팟 121곳, 28개/6카테고리 데이터셋 카탈로그
tests/          vitest 스위트(단위 105+, live 4개); 픽스처=실API 캡처 불변
scripts/        capture-fixtures.ts, live-sweep.ts, setup.sh, install-hooks.sh

Key Commands

  • npm run build - tsc 컴파일
  • npm run dev - tsx로 src/index.ts 실행
  • npm test - vitest 스위트 실행
  • npm run inspect - MCP Inspector 실행
  • npm run bundle - build 후 mcpb pack/clean -> seoul-opendata-mcp.mcpb
  • npm run prepublishOnly - build (npm publish 전 자동 실행)

Conventions

  • tests/fixtures/의 픽스처는 실API 캡처 결과로 불변입니다. 직접 수정하지 않고, 재캡처는 scripts/capture-fixtures.ts로만 합니다(tests/CLAUDE.md 참조).
  • 모든 normalize* 함수는 출력 필드를 원본 행 필드까지 추적하는 매핑 동등성 테스트를 갖습니다.
  • tool 응답은 ok() 봉투(src/tools/envelope.ts)를 사용합니다: { data, asOf, source, notes }.
  • 외부 HTTP 호출은 모두 SeoulApiClient(src/client/seoulApi.ts)를 거칩니다 - 다른 곳에서 임의 fetch 호출 금지.
  • tool description은 영어(2문장 이하) 다음에 한국어 순서로 작성합니다.
  • 커밋 접두사: feat: fix: test: docs: chore:.
  • 실제 API 키를 로그나 커밋에 남기지 않습니다. maskedKey()/maskedSubwayKey()를 사용하고, .env는 git에 커밋하지 않습니다.

Auto-Sync Rules

  • 신규 tool 추가 -> src/index.tsTOOL_NAMES에 추가, 등록하고 src/tools/CLAUDE.md를 갱신합니다.
  • src/<module>/ 신규 디렉토리 생성 -> 해당 위치에 CLAUDE.md를 만듭니다.
  • 클라이언트/정규화 계약 변경 -> docs/reference/api.md를 갱신합니다.
  • 키 처리 또는 샘플 모드 동작 변경 -> docs/reference/security.md를 갱신합니다.
  • tool 설명 또는 LLM 대상 문구 변경 -> docs/reference/agent-llm.md를 갱신합니다.

Read the full file on GitHub · 50 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. 11d ago First seen · 50 lines · 913 tokens per session scan A 13741f1d17bc

Subscribe to this mod's changes

seoul-opendata-mcp CLAUDE.md is an instructions file published in the GitHub repository whchoi98/seoul-opendata-mcp (1 stars, last pushed 25d ago), licensed MIT. It adds 913 tokens to every session, about $0.0046 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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