What is mcp-developer?

A coding agent that implements approved Model Context Protocol (MCP) tool designs in TypeScript for a Korean National Assembly API project.

Use it to modify MCP tool files, register new API codes, call the project API client, write or update unit tests, and check the TypeScript build.

It turns an API analysis and tool design into code while keeping input checks, error handling, tests, and build verification in the workflow.

How hollobit/assembly-api-mcp configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to hollobit/assembly-api-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/hollobit/assembly-api-mcp/main/.claude/agents/mcp-developer.md

Clone the repo

git clone --depth 1 https://github.com/hollobit/assembly-api-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.

README.md

[![agentmods](https://agentmods.dev/badge/agents/hollobit/assembly-api-mcp/mcp-developer/github.svg)](https://agentmods.dev/agents/hollobit/assembly-api-mcp/mcp-developer)

Your own site

<a href="https://agentmods.dev/agents/hollobit/assembly-api-mcp/mcp-developer"><img src="https://agentmods.dev/badge/agents/hollobit/assembly-api-mcp/mcp-developer/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.

Your own site · 80×15

<a href="https://agentmods.dev/agents/hollobit/assembly-api-mcp/mcp-developer"><img src="https://agentmods.dev/badge/agents/hollobit/assembly-api-mcp/mcp-developer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 20 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 302 The whole file, excluding the scripts and references it only reads on demand.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00020	$0.00302
Opus 5.5	$0.00008	$0.00121
Sonnet 5.5	$0.00004	$0.00060
Haiku 4.5	$0.00002	$0.00030

Measured 2mo ago against content hash e08d7c860f66, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

mcp-developer 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.

.claude/agents/mcp-developer.md · 41 lines

What it actually says

MCP Developer Agent

승인된 도구 설계를 TypeScript로 구현하는 전문 에이전트입니다.

역할

api-analyst의 분석 + tool-designer의 설계를 바탕으로 코드 구현
기존 도구 파일 수정 (assembly-member.ts, assembly-bill.ts 등)
codes.ts에 신규 API 코드 등록
단위 테스트 작성/수정
빌드 검증 (tsc --noEmit)

구현 규칙

불변 패턴 (spread, readonly)
함수 < 50줄, 파일 < 400줄
새 API 호출은 Promise.allSettled로 실패 격리
Zod 스키마로 입력 검증
formatToolError로 에러 핸들링
한국어 필드명 사용

참조 파일

src/tools/lite/ — Lite 도구 구현
src/tools/full/ — Full 심층 도구 구현
src/api/codes.ts — API 코드 등록
src/api/client.ts — API 클라이언트
tests/unit/ — 테스트 파일

출력

수정된 소스 파일
빌드 통과 확인
변경 요약 (_workspace/impl-{date}.md)

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.

2mo ago First seen · 41 lines · 20 tokens per session scan A e08d7c860f66

Subscribe to this mod's changes

mcp-developer is an agent published in the GitHub repository hollobit/assembly-api-mcp (94 stars, last pushed 6mo ago), licensed MIT. It adds 20 tokens to every session and 302 once invoked, about $0.0001 per session on Opus 5.5. 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 2026-08-30.

Backend and APIs Languages TypeScript api assembly openapi opendata

mcp-developer next to 6 agents from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
mcp-developerhollobit/assembly-api-mcp	Agent	94	6mo ago	MIT	A	20	Claude Code
nodejs-expertNickCrew/Claude-Cortex	Agent	66	4mo ago	MIT	A	22	Claude Code
typescript-developergonzalezpazmonica/pm-workspace	Agent	51	5d ago	MIT	A	98	Claude Code
tadpole-backend-specialistDDS-Solutions/AI-TadPole-OS	Agent	8	yesterday	MIT	A	45	Claude Code
FAI Deno Expertfrootai/frootai	Agent	7	4d ago	MIT	B	39	Claude Code
nestjs-expertcarlrannaberg/claudekit	Agent	762	7mo ago	MIT	A	0	Claude Code
node-microservice-buildervanessamarely/ai-playbook-reposito	Agent	2	3mo ago	MIT	A	25	Claude Code

assembly-api-mcp: Agent for Claude Code