GET /v1/rates/{base}/{quote}

Reads the current stored direct exchange rate for a currency pair. This is the one REST endpoint for data access in this milestone.

Need this over MCP instead? See get_rate →.

Auth

Authorization: ApiKey <key> — required.

Missing, invalid, or revoked key → 401 unauthorized:

{ "code": "unauthorized", "message": "A valid API key is required.", "request_id": "..." }

Path parameters

• base, quote — trimmed, uppercased, must match ^[A-Z0-9]{2,10}$.

Invalid format → 400 invalid_asset_symbol (checked before billing):

{ "code": "invalid_asset_symbol", "message": "Asset symbol format is invalid.", "request_id": "..." }

Billing

Exactly one request unit is charged before the rate is read. If your account’s quota is already exhausted, the response is 429 with extra fields beyond the standard error envelope:

{
  "code": "quota_exceeded",
  "message": "Request-unit quota exceeded for the current billing period.",
  "request_id": "...",
  "limit": 500,
  "remaining": 0,
  "reset_at": "2026-11-01T00:00:00Z"
}

Success — 200

curl https://your-getratesapi-host/v1/rates/EUR/USD \
  -H "Authorization: ApiKey gra_live_0000000000000000000000000000000000000000000000000000000000000000"

const res = await fetch("https://your-getratesapi-host/v1/rates/EUR/USD", {
  headers: {
    Authorization: "ApiKey gra_live_0000000000000000000000000000000000000000000000000000000000000000",
  },
});
const rate = await res.json();

{
  "base": "EUR",
  "quote": "USD",
  "rate": "1.174582",
  "as_of": "2026-09-29T11:41:32.241582Z",
  "type": "direct"
}

• rate is an exact decimal string, never a JSON number.
• as_of is RFC3339Nano UTC — the stored observation time, not the request time.
• type is always "direct" today — there are no derived cross pairs in this milestone’s scope.

Other error outcomes

These happen after a successful charge — the unit is already consumed, with no refund:

Any method other than GET/HEAD on this path returns 405 method_not_allowed.