MCP (Model Context Protocol)

Overview

MCP (Model Context Protocol) is an open protocol used to connect AI assistants and system context (data sources, tools, environments). Released by Anthropic in November 2024, it aims to solve the standardization problem of integrating AI applications with external systems.

Official Document: https://modelcontextprotocol.io GitHub: https://github.com/modelcontextprotocol

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Core concepts

1. Definition of MCP

MCP is a client-server protocol that defines:

• How AI applications (clients) request data and operations
• How data sources/tools (server) expose their capabilities
• Standard format for message transmission

2. Architecture components

┌─────────────────────────────────────────────────────────┐
│ MCP Architecture │
├─────────────────────────────────────────────────────────┤
│                                                         │
│  ┌──────────────┐         ┌──────────────┐            │
│  │   MCP Client │ ───────▶│  MCP Server  │            │
│ │ (AI application) │ ◀──────│ (data source) │ │
│  └──────────────┘         └──────────────┘            │
│         │                         │                     │
│         ▼                         ▼                     │
│  ┌──────────────┐         ┌──────────────┐            │
│ │ Claude Code │ │ File System │ │
│ │ Cursor IDE │ │ Database │ │
│ │ Cline │ │ API Service │ │
│ │ Custom Application │ │ Git Repository │ │
│  └──────────────┘         └──────────────┘            │
│                                                         │
└─────────────────────────────────────────────────────────┘

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MCP Core Competencies

1. Resources

Resource is the data reading interface exposed by the server to the client.

// Resource example
{
  "uri": "file:///Users/project/README.md",
"name": "Project README",
"description": "README file in the project root directory",
  "mimeType": "text/markdown"
}

Common resource types:

Type	URI Example	Description
Files	file:///path/to/file	Local File System
Git	git:///repo/file	Git repository content
Database	postgres://query	Database query results
API	https://api/data	HTTP API response
Memory	memory://variable	Runtime data

2. Prompt word templates (Prompts)

Prompt word template is a predefined prompt word provided by the server.

// Example of prompt word template
{
  "name": "code-review",
"description": "code review prompt word",
  "arguments": {
"file": "The path of the file to be reviewed",
"focus": "Review focus (security/performance/style)"
  }
}

3. Tools

Tools are executable functions exposed by the server.

// Tool example
{
  "name": "execute_command",
"description": "Execute commands in the terminal",
  "inputSchema": {
    "type": "object",
    "properties": {
      "command": {
        "type": "string",
"description": "Command to be executed"
      }
    }
  }
}

---

MCP transport layer

MCP supports multiple transmission methods:

1. STDIO (standard input/output)

Applies to local inter-process communication:

# Start the MCP server through STDIO
claude-code mcp install my-server
my-server --stdio

2. SSE (Server-Sent Events)

Applies to Local HTTP Communication:

// SSE connection
const client = new MCPClient({
  url: "http://localhost:3000/sse",
  transport: "sse"
});

3. Custom transmission

Supports customizing transport layers such as WebSocket and gRPC.

---

Usage scenarios

1. MCP in Claude Code

Claude Code natively supports MCP and can:

• Read project files via MCP
• Execute Git commands through MCP
• Access database via MCP
• Call external API via MCP

Configuration Example:

// .claude/mcp_config.json
{
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem", "/Users/project"]
    },
    "github": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-github"]
    }
  }
}

2. MCP in Cursor IDE

Cursor supports MCP extensions:

• Install MCP compatible server
• Cursor automatically discovers available resources
• Reference MCP resources in Chat

3. MCP in Cline

Cline (VS Code plugin) supports MCP:

• Get project context via MCP
• Execute build commands via MCP
• Access test results via MCP

---

MCP server example

File system server

#Official file system server
npx -y @modelcontextprotocol/server-filesystem /path/to/directory

GitHub server

# Official GitHub server
npx -y @modelcontextprotocol/server-github

Database server

# PostgreSQL server
npx -y @modelcontextprotocol/server-postgres "postgresql://..."

Custom server

// Customize MCP server
import { Server } from '@modelcontextprotocol/sdk/server/index.js';
import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js';

const server = new Server({
  name: 'my-custom-server',
  version: '1.0.0'
});

//Add resources
server.setRequestHandler(ListResourcesRequestSchema, async () => ({
  resources: [
    {
      uri: 'custom://data',
name: 'custom data',
description: 'My custom data source'
    }
  ]
}));

//Start the server
const transport = new StdioServerTransport();
await server.connect(transport);

---

Advantages of MCP

Advantages	Description
Standardization	Unified protocol, no need to adapt separately for each AI application
Modular	Data sources are independent of AI applications and can be reused
Extensible	Supports custom transport layers and data sources
Security	Explicit permission control and data isolation
Openness	Open source protocol, community-driven development

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Comparison of MCP and other solutions

Solutions	MCP	LangChain Tools	OpenAI Function Calling
Degree of Standardization	✅ Open Protocol	❌ Vendor Specific	❌ Vendor Specific
Transport Layer	Multiple support	HTTP/RPC	HTTP
AI Compatibility	Multi-model	Mainstream LLM	OpenAI only
Community Ecology	Rapid growth	Mature	Mature
Learning Curve	Easy	Medium	Easy

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Quick start

1. Install Claude Code MCP integration

# Install Claude Code CLI
npm install -g @anthropic-ai/claude-code

#Initialize MCP configuration
claude-code mcp init

2. Add MCP server

# Add file system server
claude-code mcp install @modelcontextprotocol/server-filesystem

# Add GitHub server
claude-code mcp install @modelcontextprotocol/server-github

3. Use in Claude Code

@mcp://filesystem/Users/project/src Please analyze the code structure in this directory

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Reference resources

Official resources

• MCP official website
• MCP GitHub
• MCP SDK Documentation

Community Resources

• MCP server list
• MCP Client List
• Claude Code MCP Documentation

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Document updated: December 2025