agentmods.dev

dev-context

A project-analysis skill that creates a compact context file describing the codebase, such as its languages, tools, tests, structure, conventions, and architecture. The file is saved as `docs/dev/context.md`.

In plain words
What is it for?
Use it before planning or changing code to identify the technology stack, test commands, directory roles, coding conventions, and whether the project is a monorepo, meaning one repository containing multiple related projects.
Why use it?
It prevents later development steps from repeatedly rediscovering how the project works. This gives planning, implementation, testing, and debugging a shared reference.

Skill for Claude CodeCodex

974 25d ago A scan 104 tokens original MIT
View the source file classmethod/tsumiki
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/classmethod/tsumiki/dev-context
Any agent
npx skills add classmethod/tsumiki --skill dev-context
Clone the repo
git clone --depth 1 https://github.com/classmethod/tsumiki

Made for: Claude Code, Codex.

Per session 104 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,657 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 $0.00104 $0.01657
Opus 5 $0.00052 $0.00829
Sonnet 5 $0.00021 $0.00331
Haiku 4.5 $0.00010 $0.00166

Measured 2d ago against content hash a718cfef9095, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

dev-context 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/dev-context/SKILL.md · 110 lines

How it starts

The opening of the file, as written. The whole thing — 110 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Dev Context

プロジェクトの技術スタック、テストフレームワーク、コーディング規約、アーキテクチャパターンを自動分析し、後続のdev-plan/dev-impl/dev-verify/dev-debugスキルが参照するコンパクトなコンテキストファイル（Memory Bank）を docs/dev/context.md に生成する。

前提知識

dev-*スキル全体像

本スキルは以下のワークフローの最初のステップ:

dev-context → dev-plan → dev-impl → dev-verify
                                ↘ dev-debug (必要時)

コンテキストファイルの役割

docs/dev/context.md は後続スキルの共通基盤:

  • dev-plan: プロジェクトパターンに沿った設計・タスク分解
  • dev-impl: テスト規約・命名規則に準拠した実装
  • dev-verify: テスト・ビルド・Lintコマンドの取得
  • dev-debug: 環境情報・依存関係の把握

500行以内のコンパクトなファイルにまとめ、後続スキルのコンテキスト消費を最小化する。

ワークフロー

Step 1: 並列探索

Explore サブエージェントを複数並列で起動し、プロジェクト情報を収集する。以下の4領域を並列に探索する:

1a. プロジェクトルート分析
  • パッケージ定義ファイルの検出: package.json, Cargo.toml, go.mod, pyproject.toml, build.gradle, pom.xml 等
  • 言語・フレームワーク・ランタイムの特定
  • パッケージマネージャの特定（npm/yarn/pnpm/bun, cargo, pip/uv 等）
1b. テスト環境分析
  • テストフレームワークの検出: Jest, Vitest, pytest, go test, cargo test, JUnit 等
  • テスト設定ファイルの確認
  • テスト実行コマンドの特定
  • テストディレクトリの構造把握
1c. ディレクトリ構造分析
  • 主要ディレクトリの役割マッピング（src/, lib/, tests/, docs/ 等）
  • エントリポイントの特定
  • モジュール構成の把握（モノレポ判定含む）
1d. コード規約サンプリング
  • 代表的なソースファイルを3-5個読み込み
  • 命名規則の推定（camelCase, snake_case, PascalCase 等）
  • エラーハンドリングパターンの抽出
  • ログ方式の特定
  • インポートスタイルの確認

サブエージェント設定: subagent_type: Explore, model: haiku（高速・低コスト）

Step 2: 情報統合

サブエージェントの結果を統合し、追加情報を取り込む。各ファイルの読み込みには行数上限を設け、コンテキスト消費を制限する:

  1. CLAUDE.md の読み込み（上限: 100行）: プロジェクトルートに CLAUDE.md がある場合:
    • 100行以内 → そのまま Read で読み込み統合する
    • 100行超過 → Explore サブエージェント（model: haiku）で全文を読ませ、コーディング規約・テスト方針・ビルド手順の 要約のみ 取得する
  2. README.md の読み込み（上限: 100行）: プロジェクト概要がある場合:
    • Read の limit: 100 で 先頭100行のみ 読み込む（概要は通常先頭にある）
  3. 設定ファイルの確認（各上限: 50行）: .eslintrc, .prettierrc, tsconfig.json 等:
    • 各ファイルを Read の limit: 50 で読み込み、追加規約を抽出する
  4. リポマップ生成: 主要モジュールとエントリポイントの一覧を構造化する（Aider的アプローチ）

Step 3: コンテキストファイル出力

docs/dev/context.md を生成する。references/context-template.md のテンプレートに従い、500行以内に収める。

出力前に docs/dev/ ディレクトリが存在しない場合は作成する（プロジェクトルートの絶対パスを使用）:

Read the full file on GitHub · 110 lines

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 · 110 lines · 104 tokens per session scan A a718cfef9095

Subscribe to this mod's changes

dev-context is a skill published in the GitHub repository classmethod/tsumiki (974 stars, last pushed 25d ago), licensed MIT. It adds 104 tokens to every session and 1,657 once invoked, about $0.0005 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 2026-08-30.

PlanningTestingWriting and docs
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