Agent skill

Dev Context

This skill should be used when the user asks to "dev-context", "プロジェクトコンテキストを生成", "プロジェクトを分析", "generate project context", "analyze project", "コンテキストを更新".

MITAuto-check passedTesting & QA

Install Dev Context

skills CLI

$ npx skills add classmethod/tsumiki --skill dev-context -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install classmethod/tsumiki dev-context --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/classmethod/tsumiki.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/dev-context .claude/skills/dev-context && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "dev-context" agent skill from https://github.com/classmethod/tsumiki/tree/main/skills/dev-context into .claude/skills/dev-context/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "dev-context", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/classmethod/tsumiki/tree/main/skills/dev-context

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add classmethod/tsumiki --skill dev-context -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install classmethod/tsumiki dev-context --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/classmethod/tsumiki.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/dev-context .agents/skills/dev-context && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "dev-context" agent skill from https://github.com/classmethod/tsumiki/tree/main/skills/dev-context into .agents/skills/dev-context/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "dev-context", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add classmethod/tsumiki --skill dev-context -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install classmethod/tsumiki dev-context --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/classmethod/tsumiki.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/dev-context .cursor/skills/dev-context && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "dev-context" agent skill from https://github.com/classmethod/tsumiki/tree/main/skills/dev-context into .cursor/skills/dev-context/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "dev-context", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/classmethod/tsumiki.git --path skills/dev-context

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add classmethod/tsumiki --skill dev-context -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install classmethod/tsumiki dev-context --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/classmethod/tsumiki.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/dev-context .gemini/skills/dev-context && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "dev-context" agent skill from https://github.com/classmethod/tsumiki/tree/main/skills/dev-context into .gemini/skills/dev-context/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "dev-context", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install classmethod/tsumiki dev-context

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add classmethod/tsumiki --skill dev-context -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/classmethod/tsumiki.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/dev-context .github/skills/dev-context && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "dev-context" agent skill from https://github.com/classmethod/tsumiki/tree/main/skills/dev-context into .github/skills/dev-context/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "dev-context", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add classmethod/tsumiki --skill dev-context -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install classmethod/tsumiki dev-context --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/classmethod/tsumiki.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/dev-context .opencode/skills/dev-context && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "dev-context" agent skill from https://github.com/classmethod/tsumiki/tree/main/skills/dev-context into .opencode/skills/dev-context/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "dev-context", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: dev-context
GitHub stars: 974
Token cost: ~755 tokens
SKILL.md length: 174 words
Files: 2 (incl. references)
Skills in repo: 14
Repo updated: Aug 7, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Works in 3 steps: 並列探索 → 情報統合 → コンテキストファイル出力
Asks to dev-context
SKILL.md covers 前提知識, ワークフロー, 信号機システム and ルール・制約, plus 1 more section
Calls git

What it does

Dev Context is an agent skill from classmethod/tsumiki. This skill should be used when the user asks to "dev-context", "プロジェクトコンテキストを生成", "プロジェクトを分析", "generate project context", "analyze project", "コンテキストを更新". 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・アーキテクチャを自動分析し、コンパクトなコンテキストファイルを生成する。

Its SKILL.md is about 760 tokens, which your agent loads only when the skill is triggered. The skill folder holds 2 other files, including reference files (for example `references/context-template.md`).

It sits in Testing & QA, covering Project scaffolding. The licence is MIT.

When your agent uses it

Asks to dev-context
プロジェクトコンテキストを生成
Generate project context
Analyze project

Example prompts

“dev-context”
“プロジェクトコンテキストを生成”
“プロジェクトを分析”
“/dev-context”

Workflow steps

3 steps, taken from the step headings in SKILL.md.

並列探索
情報統合
コンテキストファイル出力

What it can do on your machine

Read from SKILL.md and the folder at commit fa5aaff. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
- git
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md. Its commands use git, which can reach the network depending on how they are called.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Dev Context loads about 755 tokens when it runs, and up to ~2k if it reads all its reference files. Until then it costs about 59 tokens; SKILL.md has 174 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~59
When it runs · the whole SKILL.md, loaded when a task matches: ~755
With references · SKILL.md plus every file in references/, read only if the agent opens them: ~2k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from classmethod/tsumiki at commit fa5aaff, republished under its MIT licence (© classmethod). 174 words, ~755 tokens.

Download SKILL.mdSave it as .claude/skills/dev-context/SKILL.md (or your agent's skills folder). This skill also uses 1 other file; get the full folder from GitHub.

name: dev-context
description: This skill should be used when the user asks to "dev-context", "プロジェクトコンテキストを生成", "プロジェクトを分析", "generate project context", "analyze project", "コンテキストを更新". 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・アーキテクチャを自動分析し、コンパクトなコンテキストファイルを生成する。

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:

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
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）
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
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）:

bash

mkdir -p "$(git rev-parse --show-toplevel)/docs/dev"

既存の docs/dev/context.md がある場合は上書きする。差分がある場合はユーザーに通知する。

信号機システム

生成したコンテキストファイルの各セクションに確信度を付与する:

🔵 前工程指示: パッケージ定義ファイルや設定ファイルから直接読み取れた情報
🟡 妥当な推測: コードサンプリングから推定した規約・パターン
🔴 AI推論補完: 明確な根拠がなくAIが推測した情報（組織固有のルール等）

ルール・制約

context.md は 500行以内 に収める。超える場合は情報を要約・圧縮する
サブエージェントの結果は要約のみメインコンテキストに返す（トークン節約）
プロジェクト全体のコードを読まない。代表的なファイル（3-5個）からパターンを推定する
テスト実行コマンドは必ず含める（後続スキルが依存）
ビルドコマンドは検出できた場合のみ含める
既存の docs/dev/plans/ 配下のファイルには影響を与えない
Bash コマンドはプロジェクトルートの 絶対パス を使用する（$(git rev-parse --show-toplevel) でルートを取得）

追加リソース

リファレンスファイル

references/context-template.md — context.md のテンプレートと各セクションの記述ガイド

Files

SKILL.md and 1 other file (references) in skills/dev-context of classmethod/tsumiki.

SKILL.md
references/context-template.md

Open the folder on GitHubat commit fa5aaff

Compare with similar skills

Dev Context next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Dev Context compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Dev Context this skillclassmethod/tsumiki	974	—	~755	Automated safety check: Pass	MIT	2 mo ago
Desktopgridaco/grida	2.7k	—	~3.2k	Automated safety check: Notes	Apache-2.0	yesterday
Add Full Slicefullstackhero/dotnet-starter-kit	6.8k	—	~783	Automated safety check: Pass	MIT	7 days ago
Issue To Regression Testbrunosabot/streamline-card	269	—	~529	Automated safety check: Pass	MIT	4 mo ago
Veomni Patchgen ModelByteDance-Seed/VeOmni	2.2k	—	~9.6k	Automated safety check: Pass	Apache-2.0	7 days ago
Raven Test Triagemarinasundstrom/raven	108	—	~1.4k	Automated safety check: Pass	MIT	today

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Questions about Dev Context

What does Dev Context do?

This skill should be used when the user asks to "dev-context", "プロジェクトコンテキストを生成", "プロジェクトを分析", "generate project context", "analyze project", "コンテキストを更新". Dev Context is an agent skill from classmethod/tsumiki. This skill should be used when the user asks to "dev-context", "プロジェクトコンテキストを生成", "プロジェクトを分析", "generate project context", "analyze project", "コンテキストを更新".

When should I use Dev Context?

Dev Context fits situations like: asks to dev-context; プロジェクトコンテキストを生成; generate project context; analyze project.

How do I install Dev Context in Claude Code?

Run `npx skills add classmethod/tsumiki --skill dev-context -a claude-code`. Or copy the skill folder (skills/dev-context in classmethod/tsumiki) into .claude/skills/dev-context in your project. Claude Code loads it when a task matches its description.

How do I install Dev Context in Codex?

Run `npx skills add classmethod/tsumiki --skill dev-context -a codex`. Or copy the skill folder (skills/dev-context in classmethod/tsumiki) into .agents/skills/dev-context in your project. Codex loads it when a task matches its description.

Can I use Dev Context in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add classmethod/tsumiki --skill dev-context -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/dev-context, .gemini/skills/dev-context, .github/skills/dev-context and .opencode/skills/dev-context in your project.

What does Dev Context need to run?

Going by SKILL.md and its folder, Dev Context needs the command-line tools its instructions call (git).

Does Dev Context access the network?

SKILL.md contains no URLs. Its commands use git, which can reach the network depending on how they are called. This is read from the text; nothing was executed.

Is Dev Context safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Dev Context use?

Dev Context is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Dev Context use?

About 755 tokens (SKILL.md is roughly 3k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 1.2k tokens, read only when the agent opens those files.

What are the alternatives to Dev Context?

Skills that share tags, products or a category with Dev Context: Desktop (gridaco/grida, 2.7k stars), Add Full Slice (fullstackhero/dotnet-starter-kit, 6.8k stars), Issue To Regression Test (brunosabot/streamline-card, 269 stars) and Veomni Patchgen Model (ByteDance-Seed/VeOmni, 2.2k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Dev Context?

classmethod (a GitHub organization) maintains it in classmethod/tsumiki, which has 974 GitHub stars. The repository holds 14 skills in this directory. The repository was last updated on August 7, 2026.

Source: classmethod/tsumiki on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Dev Context

Facts

At a glance

What it does

When your agent uses it

Example prompts

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Dev Context

前提知識

dev-*スキル全体像

コンテキストファイルの役割

ワークフロー

Step 1: 並列探索

1a. プロジェクトルート分析

1b. テスト環境分析

1c. ディレクトリ構造分析

1d. コード規約サンプリング

Step 2: 情報統合

Step 3: コンテキストファイル出力

信号機システム

ルール・制約

追加リソース

リファレンスファイル

Files

Compare with similar skills

Similar skills

More from classmethod/tsumiki

Related

Questions about Dev Context