{"uid":"cap_x5SOEeUHXfU2Prq-7WkTT","slug":"currency-crypto-api-historical-fiat-exchange-rates-db185f8b","name":"Currency & Crypto API – Historical Fiat Exchange Rates","description":"Fiat exchange rates (ECB via Frankfurter) and crypto prices (CoinGecko) with x402 payments.","url":"https://currency.payapi.market/rates/historical?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"base":{"type":"string","description":"Base currency ISO 4217 code, e.g. 'USD'. Defaults to USD if omitted."},"date":{"type":"string","description":"Date in YYYY-MM-DD format, back to 1999-01-04, e.g. '2024-01-15'."},"symbols":{"type":"array","items":{"type":"string"},"description":"Optional list of target currency codes to restrict the response, e.g. ['EUR', 'GBP']. Omit for all rates."}}},"responseSchema":{"type":"json","example":{"base":"USD","date":"2024-01-15","rates":{"EUR":0.9187,"GBP":0.7861},"cached":false,"source":"ECB via Frankfurter"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_RgGcdFUAZ9uZhnucbomGj","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns historical fiat currency exchange rates for a given base currency and date, sourced from the European Central Bank via Frankfurter.","exampleAgentPrompt":"What were the exchange rates for USD against EUR and GBP on January 15, 2024? Use the ECB historical rates data going back to that date.","exampleUseCases":[{"title":"Historical invoice currency reconciliation","prompt":"I need to reconcile an invoice that was issued on March 10, 2023 in EUR — what was the USD to EUR exchange rate on that date?"},{"title":"Travel expense reimbursement calculation","prompt":"I have travel expenses from a business trip on November 5, 2022 — what were the GBP and JPY rates against USD on that day so I can calculate reimbursements?"},{"title":"Historical portfolio valuation","prompt":"What were the EUR, CHF, and JPY exchange rates against USD on December 31, 2021? I need to value a foreign currency portfolio at year-end."}],"resultDescription":"A JSON object containing the base currency code, the requested date, a map of target currency codes to their exchange rates (as decimals), a boolean indicating whether the result was served from cache, and a source attribution string ('ECB via Frankfurter'). Rates are available back to January 4, 1999.","failureModes":["Date before 1999-01-04: ECB data is not available before this date, likely returns an error or empty rates","Invalid date format: non-YYYY-MM-DD strings will likely cause a validation error","Unknown currency code: unrecognized ISO 4217 codes in base or symbols may return an error or be silently omitted","Weekend or holiday date: ECB does not publish rates on non-trading days, may return rates from the nearest prior trading day or an error","Payment failure: x402 micropayment not satisfied returns 402 response before data is delivered"],"whenToPreferThis":"Choose this endpoint when you need authoritative historical fiat exchange rates sourced from the European Central Bank for a specific past date, particularly for financial reconciliation, accounting, auditing, or reporting use cases where ECB data is the accepted standard. It is ideal for date-specific lookups going back to 1999. Prefer it over live-rate endpoints when the date in question is in the past, and over crypto endpoints when you need fiat-only rates.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-30T19:04:13.741Z","isFirstParty":false,"canonicalSlug":"currency-crypto-api-historical-fiat-exchange-rates-db185f8b"}