MySQL ReadOnly MCP Server

Instructions

Implementation Reference

• src/index.ts:155-165 (handler)

  Handler case for the mysql_list_databases tool. It invokes mysqlConnection.listDatabases() and returns the JSON-formatted result as text content.

  case 'mysql_list_databases': {
    const result = await mysqlConnection.listDatabases();
    return {
      content: [
        {
          type: 'text',
          text: JSON.stringify(result, null, 2),
        },
      ],
    };
  }

• src/index.ts:77-84 (registration)

  Registration of the mysql_list_databases tool in the listTools handler, including its name, description, and empty input schema.

  {
    name: 'mysql_list_databases',
    description: 'List all available databases',
    inputSchema: {
      type: 'object',
      properties: {},
    },
  },

• src/mysql-connection.ts:111-123 (helper)

  Core implementation of listDatabases method in MySQLConnection class. Executes 'SHOW DATABASES' query, extracts database names, and filters out system databases.

  async listDatabases(): Promise<string[]> {
    const query = 'SHOW DATABASES';
    const result = await this.executeQuery(query);
  
    // Extract database names from result
    return result.rows.map((row: any) => {
      const key = Object.keys(row)[0]; // Get the first column name
      return row[key];
    }).filter((db: string) => {
      // Filter out system databases
      return !['information_schema', 'mysql', 'performance_schema', 'sys'].includes(db);
    });
  }