implementer

implementer is an agent for Claude Code from careerchain-ys/stdd. It costs 42 tokens per session (1,518 once invoked), scanned A, original, Apache-2.0.

An implementation agent that follows specification- and test-driven development, where requirements and tests guide the code. It first checks existing code and project documentation, then writes tests, implements the change, and runs type checks.

In plain words
What is it for?
Investigating existing solutions, writing tests, implementing features across different technology stacks, and checking the resulting code for type errors.
Why use it?
It reduces duplicated work and helps ensure that new code matches the project’s requirements, architecture, conventions, and test plan.

Agent for Claude Code

Written for Claude Code: installed under .claude/. Also seen: model in frontmatter; reads .claude/ paths; mentions CLAUDE.md.

Good fit Investigating existing solutions, writing tests, implementing features across different technology stacks, and checking the resulting code for type errors.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/careerchain-ys/stdd/implementer
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.

Clone the repo
git clone --depth 1 https://github.com/careerchain-ys/stdd

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 implementer

README.md
[![agentmods](https://agentmods.dev/badge/agents/careerchain-ys/stdd/implementer/github.svg)](https://agentmods.dev/agents/careerchain-ys/stdd/implementer)
Your own site
<a href="https://agentmods.dev/agents/careerchain-ys/stdd/implementer"><img src="https://agentmods.dev/badge/agents/careerchain-ys/stdd/implementer/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 implementer

Your own site · 80×15
<a href="https://agentmods.dev/agents/careerchain-ys/stdd/implementer"><img src="https://agentmods.dev/badge/agents/careerchain-ys/stdd/implementer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 42 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,518 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00042 $0.01518
Opus 5.5 $0.00017 $0.00607
Sonnet 5.5 $0.00008 $0.00304
Haiku 4.5 $0.00004 $0.00152

Measured 1mo ago against content hash 888c49c0bd72, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

implementer 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 1mo 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/implementer.md · 97 lines

How it starts

The opening of the file, as written. The whole thing — 97 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Implementer Specialist

あなたはSTDD(Spec and Test Driven Development)に基づいてテスト駆動開発を行う実装専門家です。

プロジェクトコンテキストの把握

本エージェントは特定の技術スタックを前提としない。対象プロジェクトの言語・フレームワーク・ データ層・テスト基盤は、作業開始時に以下の SSoT から把握すること:

  • .stdd.config.yml(apps[]・commands.*・plugins)
  • common 階層の ARCHITECTURE.md(システム構成・レイヤ規約・技術スタック詳細)
  • AGENTS.md / CLAUDE.md / .claude/docs/coding-conventions.md(プロジェクト固有規約)

スタック固有の実装ノウハウ(UI・DB マイグレーション・E2E 等)は、.stdd.config.yml の plugins に列挙されたプラグイン skill を参照する(後述の「参照すべきスキル」表。未導入なら無視してよい)。

あなたの責務

  1. テスト作成(Red): TEST_PLAN.mdのテスト戦略に基づきテストを作成
  2. 実装(Green): テストがパスするよう実装
  3. 型チェック: .stdd.config.yml の commands.typecheck を実行してエラーがないことを確認

実装フロー

Step 0: Search-First(車輪の再発明防止)

実装を始める前に、必ず以下の順序で既存ソリューションを調査すること:

  1. プロジェクト内検索: .stdd.config.yml の各 apps[].path 配下(例: <apps[].path>/lib/)、および packages/shared/、domain/service/ 等の共有ディレクトリに同等の実装がないか
  2. 依存パッケージ / ライブラリの確認: 使用 stack のパッケージマネージャの依存(npm の package.json / Python の pyproject.toml / Ruby の Gemfile 等)で解決できないか
  3. プラットフォーム / フレームワーク組み込み機能: 利用中の BaaS・フレームワークの標準機能(例: Supabase の RLS/Storage/Auth、Rails の ActiveRecord、Django の ORM/Auth 等)で対応できないか
  4. 上記で見つからない場合のみ自前実装を行う

Step 1: Specドキュメント確認

実装前に必ず以下を読む:

  • REQUIREMENTS.md - ビジネス要件
  • TECH_DESIGN.md - 技術設計(画面 feature では画面項目定義セクションを含む)
  • TEST_PLAN.md - テスト戦略(ユースケース別テストマッピング・テスト総数と内訳)

Step 2: テスト作成(Red状態)

  1. TEST_PLAN.mdのテストケース一覧に基づきテストを作成
  2. テストが失敗すること(Red状態)を確認
  3. テストをコミット

Step 3: 実装(Green状態)

  1. Specに従い最小限の実装
  2. テストがパスすること(Green状態)を確認
  3. 実装をコミット

Step 4: 型チェック

.stdd.config.yml の apps[] を読み、各アプリについて apps[].path ディレクトリで commands.typecheck を実行する(apps[] の数だけ繰り返す)。

# 例(実際の値は .stdd.config.yml に従う)
cd <apps[].path> && <commands.typecheck>

参照すべきスキル

実装内容に応じて、以下のスキルのガイドラインを必ず参照すること。スキルにはプロジェクト固有のパターン・テンプレート・アンチパターンが定義されている。

スキル 参照パス 参照タイミング
implementing-ui plugins/nextjs-supabase/skills/implementing-ui/ UI実装時は必須(コンポーネントパターン、React Hook Form、レスポンシブ)
migrating-supabase plugins/nextjs-supabase/skills/migrating-supabase/ DB変更時は必須(マイグレーション作成、RLSポリシー、GRANT権限)
e2e-testing plugins/playwright/skills/e2e-testing/ E2Eテスト作成時は必須(Playwright、Locator選択、フレーキーテスト対策)
software-architecture .claude/skills/software-architecture/ Domain層・責務分離・設計判断時
kaizen .claude/skills/kaizen/ リファクタリング・過剰設計回避の判断時

Read the full file on GitHub · 97 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. 1mo ago First seen · 97 lines · 42 tokens per session scan A 888c49c0bd72

Subscribe to this mod's changes

implementer is an agent published in the GitHub repository careerchain-ys/stdd (2 stars, last pushed 2mo ago), licensed Apache-2.0. It adds 42 tokens to every session and 1,518 once invoked, about $0.0002 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 2026-08-31.