MCPを簡単に

MCPサーバーとは？

MCPサーバーは、Clineの機能を強化する専用の拡張機能です。Clineがウェブページの取得、画像処理、API アクセスなどの追加タスクを実行できるようにします。

MCPマーケットプレイスのウォークスルー

MCPマーケットプレイスは、様々なカテゴリにわたる数百のMCPサーバーのワンクリックインストール体験を提供します。

1. マーケットプレイスにアクセス

Clineで、トップツールバーの「Extensions」ボタン（正方形アイコン）をクリック
MCPマーケットプレイスが開き、カテゴリ別に利用可能なサーバーが表示されます

2. サーバーの閲覧と選択

カテゴリ別（Search、File-systems、Browser-automation、Research-dataなど）にサーバーを閲覧
サーバーをクリックして、その機能と要件の詳細を確認

3. インストールと設定

選択したサーバーのインストールボタンをクリック
サーバーがAPIキーを必要とする場合（ほとんどがそう）、Clineが以下をガイドします：
- APIキーの取得場所
- 安全な入力方法
サーバーはMCP設定に自動的に追加されます

4. インストールの確認

インストールが完了するとClineが確認を表示
ClineのMCP設定UIでサーバーステータスを確認

5. 新しいサーバーの使用

インストールが成功した後、Clineはサーバーの機能を自動的に統合
Clineのシステムプロンプトで新しいツールとリソースが利用可能に
新しいサーバーの機能を使用するようにClineに依頼するだけ
例：「Perplexityを使って最新のReact更新を検索してください」

企業ユーザー: 企業環境でClineを使用している場合は、組織のセキュリティポリシーに従ってサードパーティMCPサーバーをインストールする権限があることを確認してください。

What Happens Behind the Scenes

When you install an MCP server, several things happen automatically:

1. Installation Process

The server code is cloned/installed to /Users/<username>/Documents/Caret/MCP/
Dependencies are installed
The server is built (TypeScript/JavaScript compilation or Python package installation)

2. Configuration

The MCP settings file is updated with your server configuration
This file is located at: /Users/<username>/Library/Application Support/Code/User/globalStorage/saoudrizwan.claude-dev/settings/cline_mcp_settings.json
Environment variables (like API keys) are securely stored
The server path is registered

3. Server Launch

Caret detects the configuration change
Caret launches your server as a separate process
Communication is established via stdio or HTTP

4. Integration with Caret

Your server's capabilities are added to Caret's system prompt
Tools become available via use_mcp_tool commands
Resources become available via access_mcp_resource commands
Caret can now use these capabilities when prompted by the user

Troubleshooting

System Requirements

Make sure your system meets these requirements:

Node.js 18.x or newer
- Check by running: node --version
- Install from: https://nodejs.org/
- Required for JavaScript/TypeScript implementations
Python 3.10 or newer
- Check by running: python --version
- Install from: https://python.org/
- Note: Some specialized implementations may require Python 3.11+
UV Package Manager
- Modern Python package manager for dependency isolation
- Install using:
```
curl -LsSf https://astral.sh/uv/install.sh | sh
```
  Or: pip install uv
- Verify with: uv --version

If any of these commands fail or show older versions, please install/update before continuing!

Common Installation Issues

Ensure your internet connection is stable
Check that you have the necessary permissions to install new software
Verify that the API key was entered correctly (if required)
Check the server status in the MCP settings UI for any error messages

How to Remove an MCP Server

To completely remove a faulty MCP server:

Open the MCP settings file: /Users/<username>/Library/Application Support/Code/User/globalStorage/saoudrizwan.claude-dev/settings/cline_mcp_settings.json
Delete the entire entry for your server from the mcpServers object
Save the file
Restart Caret

I'm Still Getting an Error

If you're getting an error when using an MCP server, you can try the following:

Check the MCP settings file for errors
Use a Claude Sonnet model for installation
Verify that paths to your server's files are correct
Ensure all required environment variables are set
Check if another process is using the same port (for HTTP-based servers)
Try removing and reinstalling the server (remove from both the cline_mcp_settings.json file and the /Users/<username>/Documents/Caret/MCP/ directory)
Use a terminal and run the command with its arguments directly. This will allow you to see the same errors that Caret is seeing

MCP Server Rules

Caret is already aware of your active MCP servers and what they are for, but when you have a lot of MCP servers enabled, it can be useful to define when to use each server.

Utilize a .clinerules file or custom instructions to support intelligent MCP server activation through keyword-based triggers, making Caret's tool selection more intuitive and context-aware.

How MCP Rules Work

MCP Rules group your connected MCP servers into functional categories and define trigger keywords that activate them automatically when detected in your conversations with Caret.

{
	"mcpRules": {
		"webInteraction": {
			"servers": ["firecrawl-mcp-server", "fetch-mcp"],
			"triggers": ["web", "scrape", "browse", "website"],
			"description": "Tools for web browsing and scraping"
		}
	}
}

Configuration Structure

Categories: Group related servers (e.g., "webInteraction", "mediaAndDesign")
Servers: List server names in each category
Triggers: Keywords that activate these servers
Description: Human-readable category explanation

Benefits of MCP Rules

Contextual Tool Selection: Caret selects appropriate tools based on conversation context
Reduced Friction: No need to manually specify which tool to use
Organized Capabilities: Logically group related tools and servers
Prioritization: Handle ambiguous cases with explicit priority ordering

Example Usage

When you write "Can you scrape this website?", Caret detects "scrape" and "website" as triggers, automatically selecting web-related MCP servers.

For finance tasks like "What's Apple's stock price?", keywords like "stock" and "price" trigger finance-related servers.

Quick Start Template

{
	"mcpRules": {
		"category1": {
			"servers": ["server-name-1", "server-name-2"],
			"triggers": ["keyword1", "keyword2", "phrase1", "phrase2"],
			"description": "Description of what these tools do"
		},
		"category2": {
			"servers": ["server-name-3"],
			"triggers": ["keyword3", "keyword4", "phrase3"],
			"description": "Description of what these tools do"
		},
		"category3": {
			"servers": ["server-name-4", "server-name-5"],
			"triggers": ["keyword5", "keyword6", "phrase4"],
			"description": "Description of what these tools do"
		}
	},
	"defaultBehavior": {
		"priorityOrder": ["category1", "category2", "category3"],
		"fallbackBehavior": "Ask user which tool would be most appropriate"
	}
}

Add this to your .clinerules file or to your custom instructions to make Caret's MCP server selection more intuitive and context-aware.

MCPサーバーとは？​

MCPマーケットプレイスのウォークスルー​

1. マーケットプレイスにアクセス​

2. サーバーの閲覧と選択​

3. インストールと設定​

4. インストールの確認​

5. 新しいサーバーの使用​

What Happens Behind the Scenes​

1. Installation Process​

2. Configuration​

3. Server Launch​

4. Integration with Caret​

Troubleshooting​

System Requirements​

Common Installation Issues​

How to Remove an MCP Server​

I'm Still Getting an Error​

MCP Server Rules​

How MCP Rules Work​

Configuration Structure​

Benefits of MCP Rules​

Example Usage​

Quick Start Template​