DB Agent MCP Server

import { createMySQLAdapter } from "../adapters/mysql"; const db = createMySQLAdapter(); // SQLの種類を判定する関数 function isReadOnlyQuery(sql: string): boolean { const trimmed = sql.trim().toUpperCase(); // SELECTで始まるクエリのみを読み取り専用として許可 return trimmed.startsWith("SELECT") || trimmed.startsWith("SHOW") || trimmed.startsWith("DESCRIBE") || trimmed.startsWith("DESC") || trimmed.startsWith("EXPLAIN"); } // 読み取り専用クエリのバリデーション function validateReadOnlyQuery(sql: string): { valid: boolean; error?: string } { const trimmed = sql.trim().toUpperCase(); if (!isReadOnlyQuery(sql)) { return { valid: false, error: "This tool only accepts SELECT, SHOW, DESCRIBE, DESC, or EXPLAIN queries. Use run_query_write for INSERT, UPDATE, DELETE, or other write operations." }; } return { valid: true }; } // 書き込みクエリのバリデーション（SELECTは許可しない） function validateWriteQuery(sql: string): { valid: boolean; error?: string } { const trimmed = sql.trim().toUpperCase(); if (trimmed.startsWith("SELECT") || trimmed.startsWith("SHOW") || trimmed.startsWith("DESCRIBE") || trimmed.startsWith("DESC") || trimmed.startsWith("EXPLAIN")) { return { valid: false, error: "This tool does not accept SELECT queries. Use run_query_readonly for read-only operations." }; } return { valid: true }; } // 共通のクエリ実行ハンドラー async function executeQuery(sql: string) { try { const rows = await db.query(sql); return { rows }; } catch (error: any) { return { error: error.message }; } } // 読み取り専用ツール export const runQueryReadonlyTool = { name: "run_query_readonly", description: "Execute a read-only SQL query (SELECT, SHOW, DESCRIBE, DESC, EXPLAIN only) and return rows. This tool does not require approval.", parameters: { type: "object", properties: { sql: { type: "string" } }, required: ["sql"] }, handler: async ({ sql }: { sql: string }) => { const validation = validateReadOnlyQuery(sql); if (!validation.valid) { return { error: validation.error }; } return await executeQuery(sql); }, }; // 書き込みツール export const runQueryWriteTool = { name: "run_query_write", description: "Execute a write SQL query (INSERT, UPDATE, DELETE, CREATE, DROP, ALTER, etc.) and return results. This tool requires user approval.", parameters: { type: "object", properties: { sql: { type: "string" } }, required: ["sql"] }, handler: async ({ sql }: { sql: string }) => { const validation = validateWriteQuery(sql); if (!validation.valid) { return { error: validation.error }; } return await executeQuery(sql); }, }; // 後方互換性のため、既存のrunQueryToolも残す（非推奨） export const runQueryTool = { name: "run_query", description: "[DEPRECATED] Execute a SQL query and return rows. Use run_query_readonly for SELECT queries or run_query_write for write operations.", parameters: { type: "object", properties: { sql: { type: "string" } }, required: ["sql"] }, handler: async ({ sql }: { sql: string }) => { return await executeQuery(sql); }, };