Historical Rate Lookup

apiVersion: capability.naftiko.dev/v1alpha1
kind: Capability
metadata:
  name: historical-rate-lookup
  provider: currencylayer
  description: |
    Look up the end-of-day exchange rate for a specific historical date and
    currency pair. Useful for ledger reconciliation, audit trails, and
    point-in-time valuation. Available on all plans including Free.
spec:
  uses:
    - sharedCapability: currencylayer-shared
      operations: [getHistorical, listCurrencies]
  preconditions:
    - description: Date must be on or after 1999-01-01 (the earliest day Currencylayer covers).
  workflow:
    - step: validateSymbol
      operation: listCurrencies
    - step: fetchHistorical
      operation: getHistorical
      parameters:
        date: "{{ input.date }}"
        source: "{{ input.source | default: 'USD' }}"
        currencies: "{{ input.currencies }}"
  outputs:
    date: "{{ fetchHistorical.date }}"
    source: "{{ fetchHistorical.source }}"
    quotes: "{{ fetchHistorical.quotes }}"
    timestamp: "{{ fetchHistorical.timestamp }}"
  governance:
    minPlan: Free
    httpsRequired: false
    notes: |
      Historical lookup is available on all tiers including Free, but Free is HTTP-only
      and locked to USD source. Use Basic or above for HTTPS and arbitrary source currency.