MCP Integration for Claude Code Plugins

Integrate external services into Claude Code plugins using Model Context Protocol (MCP). MCP servers provide secure, structured access to databases, APIs, and other services through a standardized interface.

1. Code Execution Pattern (Recommended)

Instead of direct tool calls, expose code APIs rather than tool call definitions:

{
  "mcpServers": {
    "code-exec": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-code-exec"],
      "env": {
        "SANDBOX_PATH": "/tmp/sandbox"
      }
    }
  }
}

Benefits:

• Give Claude a sandbox execution environment with filesystem
• Let Claude write code to make tool calls
• Elegant, prompt-on-demand pattern (similar to skills)
• Reduces token overhead

2. Selective Tool Exposure

Only expose essential tools:

{
  "mcpServers": {
    "minimal-db": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-postgres"],
      "env": {
        "MCP_TOOLS": "query,schema"
      }
    }
  }
}

3. Connection Management

• Pool connections to reuse
• Lazy load servers only when needed
• Disconnect inactive servers

Database Integration

Quick Reference

1. Choose Database Type and Configure

• PostgreSQL: @modelcontextprotocol/server-postgres
• MySQL: @modelcontextprotocol/server-mysql
• SQLite: @modelcontextprotocol/server-sqlite

2. Set Environment Variables

export POSTGRES_URL="postgresql://user:pass@host:5432/db?sslmode=require"

3. Add to settings.json

{
  "mcpServers": {
    "postgres": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-postgres", "${POSTGRES_URL}"]
    }
  }
}

Resources

References

• references/mcp-configuration.md: Master configuration guide.
• references/security.md: Security best practices.
• references/performance.md: Performance tuning.
• references/schema-management.md: Schema operations.

Examples

• examples/postgres-config.json: PostgreSQL configuration.
• examples/multi-db-config.json: Multiple database setup.