# API Acre ECB FX Reference Rate Converter

> API Acre ECB FX Reference Rate Converter is a paid API for AI agents from apiacre.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-12).

Converts an amount between two currencies using validated ECB daily foreign exchange reference rates, with transparent cross-rate calculation.

## Facts

- Endpoint: POST https://apiacre.com/v1/data/ecb-fx-reference?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-12
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-acre-ecb-fx-reference-rate-converter-ac8900d2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_3E1w9ATSJCK6HEPxNkDIo

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability api-acre-ecb-fx-reference-rate-converter-ac8900d2 -d '<json body>'
```

Example prompt: Convert 250 GBP to USD using the ECB daily reference rate — use the most recent available rate on or before today and show me the cross-rate basis.

## When to prefer this

Choose this endpoint when you need a single authoritative, auditable ECB daily reference rate conversion with transparent cross-rate arithmetic and source traceability. Ideal for accounting, compliance, or reporting contexts where citing an official central bank source matters. Prefer over commercial FX APIs when ECB provenance and free-of-charge underlying data (with bounded retrieval and validation) is the requirement. Not suitable for live trading rates, real-time bid/ask spreads, or currencies outside the 30 ECB-supported pairs.

## Known failure modes

- Unsupported currency pair — only the 30 ECB-listed currencies are accepted
- No observation available on or before the requested date (e.g. market holiday, too far in past)
- ECB Data Portal temporarily unavailable causing upstream retrieval failure
- Invalid amount string that cannot be parsed as a numeric value
- Same base and quote currency provided

## How this service works

Convert an amount between two supported currencies using one validated ECB daily reference-rate observation. The underlying ECB statistics are available free from the ECB Data Portal; the fee covers bounded retrieval, validation, clearly labelled cross-rate calculation, and x402 delivery.

## Output

Returns the converted amount, the exchange rate and its inverse, the ECB reference date used, cross-rate basis (formula, basePerEur and quotePerEur values), source dataset details, reference lag in days, any warnings about data freshness or derivation, and a disclaimer that the data is reference-only. Also includes request ID, duration, and cache status.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "amount": {
   "type": "string"
  },
  "on_or_before": {
   "anyOf": [
    {
     "type": "string"
    },
    {
     "type": "null"
    }
   ]
  },
  "base_currency": {
   "enum": [
    "AUD",
    "BRL",
    "CAD",
    "CHF",
    "CNY",
    "CZK",
    "DKK",
    "EUR",
    "GBP",
    "HKD",
    "HUF",
    "IDR",
    "ILS",
    "INR",
    "ISK",
    "JPY",
    "KRW",
    "MXN",
    "MYR",
    "NOK",
    "NZD",
    "PHP",
    "PLN",
    "RON",
    "SEK",
    "SGD",
    "THB",
    "TRY",
    "USD",
    "ZAR"
   ],
   "type": "string"
  },
  "quote_currency": {
   "enum": [
    "AUD",
    "BRL",
    "CAD",
    "CHF",
    "CNY",
    "CZK",
    "DKK",
    "EUR",
    "GBP",
    "HKD",
    "HUF",
    "IDR",
    "ILS",
    "INR",
    "ISK",
    "JPY",
    "KRW",
    "MXN",
    "MYR",
    "NOK",
    "NZD",
    "PHP",
    "PLN",
    "RON",
    "SEK",
    "SGD",
    "THB",
    "TRY",
    "USD",
    "ZAR"
   ],
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {
   "rate": "1.352573464976",
   "basis": {
    "formula": "quotePerEur / basePerEur",
    "basePerEur": "0.85585",
    "quotePerEur": "1.1576",
    "denomination": "EUR"
   },
   "amount": "100",
   "source": {
    "dataset": "EXR daily euro foreign exchange reference rates",
    "provider": "European Central Bank",
    "requestUrl": "https://data-api.ecb.europa.eu/service/data/EXR/D.GBP+USD...",
    "seriesKeys": [
     "EXR.D.GBP.EUR.SP00.A",
     "EXR.D.USD.EUR.SP00.A"
    ]
   },
   "warnings": [
    "The latest common reference observation is 1 calendar day...",
    "API Acre derived this cross rate by dividing two unmodifi..."
   ],
   "disclaimer": "Reference data only, not financial advice or a guarantee ...",
   "inverseRate": "0.739331375259",
   "limitations": [
    "ECB reference rates are usually published on TARGET busin...",
    "A converted amount is arithmetic evidence only; banks, ex...",
    "ECB observations can be revised, interrupted, or withdraw...",
    "Coverage is limited to the explicitly supported active EC..."
   ],
   "retrievedAt": "2026-08-19T04:00:00+00:00",
   "baseCurrency": "GBP",
   "quoteCurrency": "USD",
   "referenceDate": "2026-08-18",
   "convertedAmount": "135.2573465",
   "referenceLagDays": 1,
   "networkRequestsMade": 1,
   "requestedOnOrBefore": null
  },
  "meta": {
   "cached": false,
   "sources": [],
   "warnings": [],
   "duration_ms": 42,
   "next_actions": []
  },
  "service": "data.ecb-fx-reference",
  "version": "1",
  "request_id": "018f1f54-7f38-7ba2-8dc3-5f90272d9f1a"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-acre-ecb-fx-reference-rate-converter-ac8900d2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from apiacre.com](https://www.zero.xyz/host/apiacre.com/llms.txt)