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This guide describes how CONA fetches daily FX rates from the ECB and how they are used in DATEV export.

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Source

  • API: ECB Data Portal
  • Endpoint pattern: https://data-api.ecb.europa.eu/service/data/EXR/D..EUR.SP00.A?startPeriod=YYYY-MM-DD&endPeriod=YYYY-MM-DD&detail=dataonly&format=jsondata
  • Reference: ECB API docs

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Storage

  • Table: exchange_rates
  • Fields:
    • base_currency: EUR
    • quote_currency: target currency (e.g., USD)
    • rate: quote per 1 EUR
    • start_date (UTC 00:00:00.000)
    • end_date (UTC 23:59:59.999)
    • source: ECB
    • raw: minimal JSON fragment with series/observation ids (for traceability)
  • Uniqueness: (base_currency, quote_currency, start_date)

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Sync

  • Core function: syncEcbFxRates({ date? })
  • Temporal activity: syncEcbFxRatesActivity
  • Workflows:
    • dailyFxSyncWorkflow({ dateIso? }) (one-shot)
    • fxDailySchedulerWorkflow() (simple daily loop; prefer Temporal Schedules in prod)
  • Task queue: FX_GLOBAL_TASK_QUEUE

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Consumption

  • Helper: getFxRateForDate({ baseCurrency, quoteCurrency, at })
  • DATEV export: when WKZ Umsatz differs from export header WKZ, Kurs is populated using FX rate for document date (UTC). Kurs is formatted with comma and 4 decimals.

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Error handling

  • Sync returns ActionResponse; Temporal activity throws on failure.
  • If no rate is available for the exact day, getFxRateForDate selects the latest available rate on or before the date; for cross pairs, triangulates via EUR.
  • Network/structure errors are logged and surfaced via error.

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Notes

  • All dates are handled in UTC.
  • Use JSON format from the ECB (format=jsondata).