parse_rakuten_csv

Instructions

Implementation Reference

• src/index.ts:84-117 (handler)

  Handler function for parse_rakuten_csv that validates input via Zod schema, calls mapRakutenCsv to parse the CSV, and returns the result as JSON.

  function handleParseRakutenCsv(args: unknown): string {
    const parsed = ParseRakutenCsvInputSchema.parse(args);
    const result = mapRakutenCsv(parsed.csvContent);
  
    if (!result.ok) {
      return JSON.stringify(
        {
          ok: false,
          error: result.error,
        },
        null,
        2,
      );
    }
  
    const totalAmount = result.rows.reduce((sum, r) => sum + r.amount, 0);
  
    return JSON.stringify(
      {
        ok: true,
        rowCount: result.rows.length,
        totalAmount,
        cashFlows: result.rows.map((r) => ({
          date: r.date,
          amount: r.amount,
          transactionType: r.transactionType,
          fundName: r.fundName,
        })),
        warnings: result.warnings,
      },
      null,
      2,
    );
  }

• src/index.ts:177-192 (registration)

  Tool registration in ListToolsRequestSchema handler with name 'parse_rakuten_csv', description, and inputSchema (csvContent string).

  {
    name: 'parse_rakuten_csv',
    description:
      'Parse a Rakuten Securities transaction CSV (取引履歴) and convert it into a normalized cash flow list. Handles 買付/売却 transaction types automatically. The output can be fed directly into calculate_xirr.',
    inputSchema: {
      type: 'object',
      properties: {
        csvContent: {
          type: 'string',
          description:
            'Raw CSV text exported from Rakuten Securities. Note: Rakuten exports are typically Shift_JIS encoded; decode to UTF-8 before passing.',
        },
      },
      required: ['csvContent'],
    },
  },

• src/index.ts:205-207 (registration)

  Switch-case dispatch mapping the tool name 'parse_rakuten_csv' to the handler function handleParseRakutenCsv.

  case 'parse_rakuten_csv':
    text = handleParseRakutenCsv(args);
    break;

• src/index.ts:38-45 (schema)

  Zod input validation schema for parse_rakuten_csv requiring a non-empty csvContent string.

  const ParseRakutenCsvInputSchema = z.object({
    csvContent: z
      .string()
      .min(1, 'csvContent must not be empty')
      .describe(
        'Raw CSV text exported from Rakuten Securities. Headers must include 約定日, 取引, ファンド名, 受渡金額/(ポイント利用)[円].',
      ),
  });

• src/parsers/rakuten.ts:39-95 (helper)

  Core CSV parsing logic for Rakuten Securities CSV. Validates headers, normalizes dates, parses amounts, and converts buy/sell transactions to signed cash flows.

  export function mapRakutenCsv(csvText: string): MapResult {
    const parsed = parseCsv(csvText);
    if (!parsed.ok) {
      return { ok: false, error: parsed.error };
    }
  
    const { headers, rows: dataRows } = parsed;
  
    const indices: Record<string, number> = {};
    for (const name of REQUIRED_HEADERS) {
      const idx = findColumnIndex(headers, name);
      if (idx === -1) {
        return {
          ok: false,
          error: `必要なカラム「${name}」が見つかりません`,
        };
      }
      indices[name] = idx;
    }
  
    const results: RakutenCsvRow[] = [];
    const warnings: string[] = [];
  
    for (let i = 0; i < dataRows.length; i++) {
      const row = dataRows[i];
      const rawDate = row[indices['約定日']] ?? '';
      const rawTransaction = row[indices['取引']] ?? '';
      const rawFundName = row[indices['ファンド名']] ?? '';
      const rawAmount = row[indices['受渡金額/(ポイント利用)[円]']] ?? '';
  
      const date = normalizeDate(rawDate);
      if (!date) {
        warnings.push(`${i + 2}行目: 日付「${rawDate}」を解析できません`);
        continue;
      }
  
      const amount = parseAmount(rawAmount);
      if (amount === null) {
        warnings.push(`${i + 2}行目: 金額「${rawAmount}」を解析できません`);
        continue;
      }
  
      const isBuy = rawTransaction === '買付';
      results.push({
        date,
        amount: isBuy ? amount : -amount,
        transactionType: rawTransaction,
        fundName: rawFundName,
      });
    }
  
    if (results.length === 0) {
      return { ok: false, error: '有効な取引データがありません' };
    }
  
    return { ok: true, rows: results, warnings };
  }