MySQL MCP Server

Instructions

Implementation Reference

• src/index.ts:88-96 (handler)

  The handler for the 'query' tool executes a read-only SQL query on the MySQL database and returns the result rows as a formatted JSON string.

  case "query": {
    const sql = request.params.arguments?.sql as string;
    await connection.query('START TRANSACTION READ ONLY');
    const [rows] = await connection.query(sql);
    return {
      content: [{ type: "text", text: JSON.stringify(rows, null, 2) }],
      isError: false,
    };
  }

• src/index.ts:42-48 (schema)

  Input schema definition for the 'query' tool, specifying an object with a required 'sql' string property.

  inputSchema: {
    type: "object",
    properties: {
      sql: { type: "string" },
    },
    required: ["sql"],
  },

• src/index.ts:39-49 (registration)

  Registration of the 'query' tool in the tools list returned by the ListToolsRequestHandler.

  {
    name: "query",
    description: "Executes a read-only SQL query.",
    inputSchema: {
      type: "object",
      properties: {
        sql: { type: "string" },
      },
      required: ["sql"],
    },
  },