spec-flow MCP — ユースケース, インストール & ライブデモ

なぜ使うのか

主な機能

Five-phase workflow: Proposal → Requirements (EARS format) → Design → Tasks → Implementation
Each phase writes a Markdown doc into .spec-flow/ so decisions are auditable
Gated transitions — Claude pauses for confirmation before advancing
Multilingual triggers: English plus Chinese ('写个方案', '做个规划')
Escape hatches: --fast skips gates, --skip-design suits simpler features

ライブデモ

実際の動作

spec-flow-skill.replay ▶ 準備完了

0/0

インストール

クライアントを選択

~/Library/Application Support/Claude/claude_desktop_config.json · Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "spec-flow-skill": {
      "command": "git",
      "args": [
        "clone",
        "https://github.com/echoVic/spec-flow",
        "~/.claude/skills/spec-flow"
      ],
      "_inferred": true
    }
  }
}

Claude Desktop → Settings → Developer → Edit Config を開く。保存後、アプリを再起動。

~/.cursor/mcp.json · .cursor/mcp.json

{
  "mcpServers": {
    "spec-flow-skill": {
      "command": "git",
      "args": [
        "clone",
        "https://github.com/echoVic/spec-flow",
        "~/.claude/skills/spec-flow"
      ],
      "_inferred": true
    }
  }
}

Cursor は Claude Desktop と同じ mcpServers スキーマを使用。プロジェクト設定はグローバルより優先。

VS Code → Cline → MCP Servers → Edit

{
  "mcpServers": {
    "spec-flow-skill": {
      "command": "git",
      "args": [
        "clone",
        "https://github.com/echoVic/spec-flow",
        "~/.claude/skills/spec-flow"
      ],
      "_inferred": true
    }
  }
}

Cline サイドバーの MCP Servers アイコンをクリックし、"Edit Configuration" を選択。

~/.codeium/windsurf/mcp_config.json

{
  "mcpServers": {
    "spec-flow-skill": {
      "command": "git",
      "args": [
        "clone",
        "https://github.com/echoVic/spec-flow",
        "~/.claude/skills/spec-flow"
      ],
      "_inferred": true
    }
  }
}

Claude Desktop と同じ形式。Windsurf を再起動して反映。

~/.continue/config.json

{
  "mcpServers": [
    {
      "name": "spec-flow-skill",
      "command": "git",
      "args": [
        "clone",
        "https://github.com/echoVic/spec-flow",
        "~/.claude/skills/spec-flow"
      ]
    }
  ]
}

Continue はマップではなくサーバーオブジェクトの配列を使用。

~/.config/zed/settings.json

{
  "context_servers": {
    "spec-flow-skill": {
      "command": {
        "path": "git",
        "args": [
          "clone",
          "https://github.com/echoVic/spec-flow",
          "~/.claude/skills/spec-flow"
        ]
      }
    }
  }
}

context_servers に追加。保存時に Zed がホットリロード。

claude mcp add spec-flow-skill -- git clone https://github.com/echoVic/spec-flow ~/.claude/skills/spec-flow

ワンライナー。claude mcp list で確認、claude mcp remove で削除。

ユースケース

実用的な使い方： spec-flow

Turn a vague feature idea into a documented spec and implementation

👤 Engineers pushing back against 'just start coding' ⏱ ~60 min intermediate

使うタイミング： PM handed you a one-liner and you'd rather spend 20 minutes writing a spec than 2 days writing the wrong code.

前提条件

Skill cloned to ~/.claude/skills/spec-flow — git clone https://github.com/echoVic/spec-flow ~/.claude/skills/spec-flow

フロー

Invoke the workflow

spec-flow: add multi-region failover to our billing service.✓ コピーしました

→ Claude writes .spec-flow/proposal.md and waits for confirmation
Confirm or edit each phase

Proposal looks good — proceed to requirements.✓ コピーしました

→ requirements.md appears with EARS-format statements
Implement from the task list

Start the implementation phase. Work through tasks.md top-to-bottom.✓ コピーしました

→ Code changes that map 1:1 to task checkboxes

結果： A feature ships with the spec still alive in .spec-flow/ — future you can see why every decision happened.

注意点

You're hacking a 10-minute fix and the skill adds 4 gates — Use --fast or just skip the skill for trivial work

組み合わせ： github · filesystem

Reverse-engineer a spec for existing code before refactoring

👤 Engineers inheriting undocumented modules ⏱ ~45 min intermediate

使うタイミング： About to refactor something nobody wrote a spec for.

フロー

Ask Spec-Flow to backfill

spec-flow --skip-design: backfill proposal and requirements.md for the existing src/auth module.✓ コピーしました

→ Clean EARS requirements extracted from actual code behavior
Use the spec as refactor target

Now design phase — how would we restructure while preserving these requirements?✓ コピーしました

→ design.md that maps new architecture to existing requirements

結果： A refactor grounded in a written contract instead of tribal knowledge.

組み合わせ： filesystem

組み合わせ

他のMCPと組み合わせて10倍の力を

spec-flow-skill + github

Commit .spec-flow/ artifacts alongside code so the spec lives in the repo history

After implementation, commit .spec-flow/ + src/ changes in one PR titled after the proposal.✓ コピーしました

spec-flow-skill + planning-with-files

Spec-Flow drives phase structure; planning-with-files keeps cross-session progress memory

Use spec-flow for the phases and planning-with-files for progress.md tracking across days.✓ コピーしました

ツール

このMCPが提供する機能

ツール	入力	呼び出すタイミング
proposal_phase	feature description	Start of a new feature
requirements_phase	approved proposal	After proposal confirmed
design_phase	approved requirements	After requirements confirmed; skippable with --skip-design
tasks_phase	approved design	Before implementation
implementation_phase	approved tasks	Final phase — actually build it

コストと制限

運用コスト

APIクォータ: None
呼び出しあたりのトークン: Each phase re-reads prior .spec-flow/ docs, so context grows across phases
金額: Free — skills are local files
ヒント: Use --fast on simple features; gates only earn their keep on 2+ day work.

セキュリティ

権限、シークレット、影響範囲

認証情報の保管： No credentials — pure prompts

データ送信先： None — .spec-flow/ stays in your working directory

.spec-flow/ files will be committed unless you .gitignore them; most teams want them committed.

トラブルシューティング

よくあるエラーと対処法

Skill not invoked — Claude codes without writing proposal.md

Use one of the trigger phrases exactly: 'spec-flow', 'spec mode', 'need a plan', '写个方案'.

確認： ls ~/.claude/skills/spec-flow/SKILL.md

SKILL.md frontmatter wrong

Re-clone the repo; description is what drives auto-activation.

確認： head ~/.claude/skills/spec-flow/SKILL.md

Wrong trigger keywords — Claude skips phases

Don't say '--fast' unintentionally. If you want full gates, omit flags and say 'spec-flow'.

代替案

spec-flow 他との比較

代替案	代わりに使う場面	トレードオフ
planning-with-files	You want durable memory across sessions rather than phase gating	Different axis — complementary, not competing
Freeform dev	Feature is 1-2 hours of work	Faster, but no audit trail

その他

リソース

📖 GitHub の公式 README を読む

🐙 オープンな issue を見る

🔍 400以上のMCPサーバーとSkillsを見る