Claude Code MCP Complete Guide

What is Claude Code MCP?

Claude Code is Anthropic's official AI command-line tool, while MCP (Model Context Protocol) is the protocol that allows Claude Code to connect to external tools and services.

Put simply, MCP turns Claude Code from an AI assistant that can only read and write local files into a super assistant that can access GitHub, databases, APIs, and cloud services.

Why use MCP in Claude Code?

Claude Code without MCP

What you can do:
✓ Read local files
✓ Edit code
✓ Run commands
✓ Use Bash tools

What you cannot do:
✗ View your GitHub Issues
✗ Access a cloud database
✗ Call external APIs
✗ Get real-time weather

Claude Code with MCP

What you can do:
✓ All original functions
✓ View / create GitHub Issues and PRs
✓ Query SQLite and PostgreSQL databases
✓ Access external services such as Notion and Slack
✓ Get real-time weather and map data
✓ Browser automation
✓ ...and more

Quick Start

Step 1: Understand where the config files live

Claude Code's MCP configuration files are located at:

It is recommended to use project-level config first, so different projects can use different MCP services.

Step 2: Add MCP servers with natural language

In Claude Code, you do not need to manually edit configuration files or memorize commands. You can describe what you want in natural language:

You: Help me add a GitHub MCP server. My token is ghp_xxx

Claude: I'll help you configure the GitHub MCP server...

[Automatically updates .claude/mcp.json]

You: Add a SQLite database server. The database file is at ./data/app.db

Claude: Okay, I'll configure the SQLite MCP server...

You: Add an HTTP-type MCP server with the address https://api.example.com/mcp

Claude: I'll add that remote MCP server...

Step 3: Verify the configuration

Ask Claude Code directly:

You: What MCP servers are available now?

Claude: Currently configured MCP servers:
• github - GitHub integration
• sqlite - SQLite database
• filesystem - Filesystem access

Or use the diagnostic command:

/doctor

Step 4: Start using it

Once configuration succeeds, you can call MCP functions directly with natural language:

You: Help me create an Issue on GitHub

Claude: I can help you create a GitHub Issue. Please tell me:
- the repository address, for example owner/repo
- the Issue title
- the Issue description

Natural-language management in Claude Code

View and manage MCP servers

You can interact with Claude Code entirely in natural language:

You: List all configured MCP servers

You: Check the connection status of the MCP servers

You: Delete the MCP server named notion

You: Update the token for the github server

Diagnose problems

When you run into problems:

You: Check what's wrong with the MCP connection

Claude: [will automatically run diagnostics, analyze configuration files, and check server status]

Configuration methods in detail

User-level config, global

Edit ~/.claude.json:

{
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "/Users/yourname/Documents"]
    },
    "github": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-github"],
      "env": {
        "GITHUB_PERSONAL_ACCESS_TOKEN": "your-token"
      }
    }
  }
}

Project-level config, recommended

Edit .claude/mcp.json in the project root:

{
  "mcpServers": {
    "project-db": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-sqlite", "--db-path", "./data/app.db"]
    }
  }
}

Advantages of project-level config:

• Team members can share the config by committing it to Git
• Different projects can use different MCP services
• Configuration is more flexible and does not pollute global settings

Transport modes

Claude Code supports three transport modes:

STDIO, local process

{
  "mcpServers": {
    "local-tool": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "/path"]
    }
  }
}

HTTP, remote service

{
  "mcpServers": {
    "remote-api": {
      "url": "https://api.example.com/mcp",
      "transport": "http",
      "headers": {
        "Authorization": "Bearer your-token"
      }
    }
  }
}

SSE, server-sent events

{
  "mcpServers": {
    "streaming": {
      "url": "https://api.example.com/sse",
      "transport": "sse"
    }
  }
}