Exchange rates

Reference exchange rates (not trading prices) from one base currency, latest or on a date. frankfurter supports any base daily; ecb supports base EUR; us-treasury supports base USD with quarterly rates; bcb-ptax supports a foreign base with quote BRL.

Endpoint	POST /v1/exchange-rate-queries
Scope	exchange_rate:query
MCP tool	exchange_rate
Usage units	rates

Usage units appear in execution.usage.units for reconciliation and billing.

Request fields

Field	Type	Required	Description
invocation_id	string	yes	The market’s invocation id: one execution per id and operation, so a retry with the same id is rejected instead of charged twice. 1-128 characters of A-Z a-z 0-9 . _ : -.
provider	string	yes	Provider that serves the request; choose by the coverage described for this tool. One of: frankfurter, us-treasury
base	string	yes	ISO 4217 base currency, for example USD or EUR.
quotes	string[]	yes	1-20 ISO 4217 quote currencies.
date	string	no	Optional YYYY-MM-DD; omitted means the latest published rates.

Providers

Provider	Region	Source	Limits
frankfurter	EU	Frankfurter (ECB and other reference rates), any base, daily	max_quotes: 20, timeout_seconds: 30
us-treasury	US	US Treasury rates, base USD, quarterly	max_quotes: 20, timeout_seconds: 30

Example

curl

curl -sS https://services.zgi.im/v1/exchange-rate-queries \
  -H "Authorization: Bearer $ZGI_SERVICES_TOKEN" \
  -H 'Content-Type: application/json' \
  -d '{"invocation_id": "docs-1791778521-exchange_rate", "provider": "frankfurter", "base": "USD", "quotes": ["CNY", "EUR"], "date": "2026-10-09"}'

HTTP

POST /v1/exchange-rate-queries HTTP/1.1
Host: services.zgi.im
Authorization: Bearer <token>
Content-Type: application/json

{
  "invocation_id": "docs-1791778521-exchange_rate",
  "provider": "frankfurter",
  "base": "USD",
  "quotes": [
    "CNY",
    "EUR"
  ],
  "date": "2026-10-09"
}

MCP

Over MCP, the tool arguments are exactly the HTTP request body.

request.json

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "exchange_rate",
    "arguments": {
      "invocation_id": "docs-1791778521-exchange_rate",
      "provider": "frankfurter",
      "base": "USD",
      "quotes": [
        "CNY",
        "EUR"
      ],
      "date": "2026-10-09"
    }
  }
}

curl -sS https://services.zgi.im/v1/mcp \
  -H "Authorization: Bearer $ZGI_SERVICES_TOKEN" \
  -H 'Content-Type: application/json' -H 'Accept: application/json, text/event-stream' \
  -H 'MCP-Protocol-Version: 2025-11-25' \
  -d @request.json

Response

A real response, with lists cut to two items and long text shortened.

{
  "code": 0,
  "message": "success",
  "data": {
    "execution": {
      "id": "exe_01a12e52a9647c6a80db06795b1a868e",
      "invocation_id": "docs-1791778521-exchange_rate",
      "capability": "exchange_rate",
      "operation": "exchange_rate.query",
      "provider": "frankfurter",
      "outcome": "succeeded",
      "error_category": null,
      "error_code": null,
      "usage": {
        "provider_requests": 1,
        "units": [
          {
            "name": "rates",
            "value": 2,
            "source": "measured"
          }
        ]
      },
      "upstream_ref": null,
      "request_id": "req_fda09169da0b3aea3c6190c0",
      "started_at": "2026-10-12T04:15:31.684811913Z",
      "finished_at": "2026-10-12T04:15:32.12019483Z",
      "duration_ms": 435
    },
    "result": {
      "base": "USD",
      "rate_date": "2026-10-09",
      "requested_date": "2026-10-09",
      "rates": [
        {
          "quote": "CNY",
          "rate": 6.693
        },
        {
          "quote": "EUR",
          "rate": 0.89154
        }
      ],
      "unavailable_quotes": [],
      "source": {
        "name": "Frankfurter (central bank reference rates)",
        "kind": "reference"
      },
      "retrieved_at": "2026-10-12T04:15:32.120169681Z"
    }
  }
}