# Currency Converter (ECB Reference Rates)

> Currency Converter (ECB Reference Rates) is a paid API for AI agents from api.stablecoingateways.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-30).

Converts a monetary amount from one currency to up to 10 others using the latest or historical European Central Bank reference rates, returning the rate, converted amount, and rate date for each target currency.

## Facts

- Endpoint: GET https://api.stablecoingateways.com/v1/fx/convert?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/currency-converter-ecb-reference-rates-a995d8c5
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Ledjhyq5g7qEfzyOAd6FU

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 currency-converter-ecb-reference-rates-a995d8c5
```

Example prompt: Can you convert 250 USD to EUR, GBP, and JPY using the latest ECB reference rate and tell me the rate and converted amount for each?

## When to prefer this

Choose this endpoint when you need authoritative, ECB-sourced reference exchange rates for up to 10 currency pairs in a single call, including historical rates within the last 90 days. It is ideal for financial reporting, invoicing, compliance, or any use case requiring a verifiable, signed receipt of the conversion. Prefer this over generic FX APIs when ECB provenance and auditability matter, or when converting from/to multiple currencies simultaneously without making multiple requests.

## Known failure modes

- Unsupported currency code returns an error — only 30 ECB-supported currencies are available
- Date older than 90 days is rejected — historical data is limited to the last 90 days
- Weekend or ECB holiday dates may return the most recent available rate, not the requested date
- Invalid amount format (non-numeric or too many decimal places) results in a validation error
- More than 10 target currencies in the 'to' parameter will fail schema validation
- Rate unavailable for cross-rate pairs not directly published by ECB — derived rates may have reduced precision

## How this service works

Currency converter (ECB reference rates): convert an amount from one currency to one or more others, e.g. 250 USD to EUR, GBP and JPY, at the latest European Central Bank rate or any day in the last 90 days. Returns the rate, converted amount and rate date for each target. 30 currencies. Reference rates, not transaction rates. Source: ECB. Signed receipt.

## Output

Returns a JSON object with the source currency, amount, rate date, and a conversions map where each key is a target currency code containing the exchange rate and converted amount. Also includes a note that these are ECB reference (informational) rates, a cross_rates_derived boolean, and an Ed25519-signed receipt with endpoint ID, timestamp, price, transaction hash, and request/response hashes for auditability.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "headers": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "queryParams": {
     "type": "object",
     "required": [
      "from",
      "to",
      "amount"
     ],
     "properties": {
      "to": {
       "type": "string",
       "pattern": "^[A-Za-z]{3}(,[A-Za-z]{3}){0,9}$",
       "description": "Comma-separated target currencies (ISO 4217), 1-10"
      },
      "date": {
       "type": "string",
       "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
       "description": "Rate date YYYY-MM-DD within the last 90 days; default latest"
      },
      "from": {
       "type": "string",
       "pattern": "^[A-Za-z]{3}$",
       "description": "Source currency (ISO 4217)"
      },
      "amount": {
       "type": "string",
       "pattern": "^[0-9]{1,15}(\\.[0-9]{1,8})?$",
       "description": "Amount to convert"
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "data",
      "receipt"
     ],
     "properties": {
      "data": {
       "type": "object",
       "$schema": "https://json-schema.org/draft/2020-12/schema",
       "properties": {
        "from": {
         "type": "string"
        },
        "note": {
         "type": "string"
        },
        "amount": {
         "type": "integer"
        },
        "source": {
         "type": "string"
        },
        "window": {
         "type": "array",
         "items": {
          "type": "string"
         }
        },
        "rate_date": {
         "type": "string"
        },
        "provenance": {
         "type": "object",
         "description": "Additive evidence block (sg-provenance/1): per-fact source, retrieval time, limits; no score or verdict. Full schema in OpenAPI."
        },
        "conversions": {
         "type": "object",
         "properties": {
          "EUR": {
           "type": "object"
          },
          "GBP": {
     
… (truncated)
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {
   "from": "USD",
   "note": "ECB reference rates are for information only and are not transaction rates.",
   "amount": 250,
   "source": "European Central Bank euro foreign exchange reference rates. Source: ECB. This informat...",
   "window": [
    "2026-07-24"
   ],
   "rate_date": "2026-10-21",
   "conversions": {
    "EUR": {
     "rate": 0.89015489,
     "amount": 222.538723
    },
    "GBP": {
     "rate": 0.74617233,
     "amount": 186.543083
    },
    "JPY": {
     "rate": 157.87787075,
     "amount": 39469.467688
    }
   },
   "requested_date": null,
   "cross_rates_derived": true
  },
  "receipt": {
   "v": 1,
   "ts": "2026-10-22T09:00:00Z",
   "sig": "hex",
   "price": {
    "asset": "USDC",
    "amount": "1000",
    "network": "eip155:84532"
   },
   "log_seq": 1,
   "tx_hash": "0x..",
   "endpoint_id": "fx-convert-v1",
   "request_hash": "hex",
   "response_hash": "hex"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/currency-converter-ecb-reference-rates-a995d8c5/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
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