MCP (Model Context Protocol)

[AI 호스트 애플리케이션]          [MCP 서버들]
  ┌─────────────────┐            ┌──────────────┐
  │  Claude / GPT   │◄──────────►│ GitHub 서버  │
  │                 │  MCP 표준  ├──────────────┤
  │  [MCP Client]   │◄──────────►│ Slack 서버   │
  └─────────────────┘  JSON-RPC  ├──────────────┤
                                 │ DB 서버      │
                                 └──────────────┘

// 1. Tools (함수 실행)
{ "method": "tools/call", "params": { "name": "create_github_pr", ... } }

// 2. Resources (데이터 읽기)
{ "method": "resources/read", "params": { "uri": "github://repos/owner/repo/issues/123" } }

// 3. Prompts (프롬프트 템플릿)
{ "method": "prompts/get", "params": { "name": "code_review_template" } }

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

const server = new Server(
  { name: "my-database-server", version: "1.0.0" },
  { capabilities: { tools: {} } }
);

server.setRequestHandler("tools/list", async () => ({
  tools: [{ name: "query_db", description: "Execute a read-only SQL query", ... }]
}));

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

// ~/.claude/claude_desktop_config.json
{
  "mcpServers": {
    "github": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-github"],
      "env": { "GITHUB_PERSONAL_ACCESS_TOKEN": "<token>" }
    },
    "postgres": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-postgres"],
      "env": { "POSTGRES_CONNECTION_STRING": "postgresql://..." }
    }
  }
}