dev-browser 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

CDP browser as a skill — no separate MCP setup
Screenshots between steps for visual grounding
DOM snapshots tuned for LLM consumption (size-aware)
Works with Chromium; local or containerized
MIT licensed

ライブデモ

実際の動作

準備完了

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": {
    "dev-browser-skill": {
      "command": "git",
      "args": [
        "clone",
        "https://github.com/SawyerHood/dev-browser",
        "~/.claude/skills/dev-browser"
      ],
      "_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": {
    "dev-browser-skill": {
      "command": "git",
      "args": [
        "clone",
        "https://github.com/SawyerHood/dev-browser",
        "~/.claude/skills/dev-browser"
      ],
      "_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": {
    "dev-browser-skill": {
      "command": "git",
      "args": [
        "clone",
        "https://github.com/SawyerHood/dev-browser",
        "~/.claude/skills/dev-browser"
      ],
      "_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": {
    "dev-browser-skill": {
      "command": "git",
      "args": [
        "clone",
        "https://github.com/SawyerHood/dev-browser",
        "~/.claude/skills/dev-browser"
      ],
      "_inferred": true
    }
  }
}

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

~/.continue/config.json

{
  "mcpServers": [
    {
      "name": "dev-browser-skill",
      "command": "git",
      "args": [
        "clone",
        "https://github.com/SawyerHood/dev-browser",
        "~/.claude/skills/dev-browser"
      ]
    }
  ]
}

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": {
    "dev-browser-skill": {
      "command": {
        "path": "git",
        "args": [
          "clone",
          "https://github.com/SawyerHood/dev-browser",
          "~/.claude/skills/dev-browser"
        ]
      }
    }
  }
}

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

claude mcp add dev-browser-skill -- git clone https://github.com/SawyerHood/dev-browser ~/.claude/skills/dev-browser

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： dev-browser

Do quick web research without setting up an MCP

👤 Devs who don't want Playwright in their MCP config ⏱ ~15 min beginner

使うタイミング： You want your Claude Code session to browse something once without committing to a persistent browser server.

前提条件

Skill installed — git clone https://github.com/SawyerHood/dev-browser ~/.claude/skills/dev-browser
Chromium available — npx playwright install chromium fetches the binary

フロー

Spin up

Use dev-browser. Open https://vercel.com/docs/functions. List the sidebar sections.✓ コピーしました

→ Headings extracted with anchor URLs
Drill in

Navigate to "Runtime" — read the page and summarize the three runtime options in one paragraph each.✓ コピーしました

→ Three paragraphs with citations to URL fragments
Capture

Screenshot the pricing section for my notes.✓ コピーしました

→ Screenshot saved locally

結果： Research done with a browser when you needed one, without ongoing infrastructure.

注意点

Chromium binary missing — Run npx playwright install chromium once

組み合わせ： filesystem

Sanity check a login flow on a staging env

👤 QA-minded devs pre-deploy ⏱ ~5 min beginner

使うタイミング： Before deploying, you want to click through the critical happy path once.

フロー

Open

Use dev-browser. Open https://staging.myapp.com, take a screenshot.✓ コピーしました

→ Landing page screenshot
Sign in

Click "Sign in", enter [email protected] / Test1234, submit.✓ コピーしました

→ Post-login dashboard captured
Confirm

Is the "Welcome, qa" string visible on the page?✓ コピーしました

→ Yes/no + screenshot

結果： A 60-second smoke test before clicking Deploy.

注意点

CAPTCHA on login — Add a test-only bypass in staging; dev-browser is not a captcha breaker

組み合わせ

他のMCPと組み合わせて10倍の力を

dev-browser-skill + filesystem

Save screenshots alongside notes

After every step, screenshot into /notes/web-research/.✓ コピーしました

dev-browser-skill + chrome-devtools

When you need devtools-level depth, escalate to chrome-devtools MCP

dev-browser gave me the page — now use chrome-devtools to check the network waterfall.✓ 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
open_url	url	Navigate
click	selector\|text	Interact
type	selector, text	Enter text
snapshot	none	Ground in current state

コストと制限

運用コスト

APIクォータ: N/A
呼び出しあたりのトークン: DOM snapshots size-gated; screenshots base64
金額: Free
ヒント: Skip snapshots when not needed — the screenshot alone is often enough

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： None

データ送信先： Direct to sites you navigate to

Don't enter real credentials on sites in agent-driven sessions — use test accounts

トラブルシューティング

よくあるエラーと対処法

Error: Executable doesn't exist at chromium path

npx playwright install chromium — the skill assumes Playwright's binaries

Selector not found

Run snapshot first; pick selector from real DOM, not guessed

Page blocks automation

Site detected headless — try running with headless=false in skill config

代替案

dev-browser 他との比較

代替案	代わりに使う場面	トレードオフ
playwright MCP	You want a persistent, MCP-registered browser	More setup; skill is lighter
mcp-chrome	You need your real logged-in Chrome	Not a headless test browser

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