# Exchange Rates API

> Read delayed ECB reference exchange rates, convert an amount, and list supported currencies via the Frankfurter API.

Each POST has a fixed USDC price on Base, paid with the x402 exact scheme. The request is validated first, and payment settles only after a successful (2xx) result. Failed calls are not charged.

1. POST JSON matching the requestBody. Invalid input returns 400 with no payment challenge.
2. A valid unpaid call returns 402 with the exact amount and payTo.
3. Pay and retry with payment-signature. Payment settles only if the operation returns 2xx. A 4xx/5xx is not charged.

- Product: https://www.brainiac.software/api/fx
- Docs: https://www.brainiac.software/api/fx/docs
- OpenAPI: https://www.brainiac.software/api/fx/openapi.json
- Contact: support@brainiac.software (https://www.brainiac.software/contact)

## Operations

### POST /api/v1/fx/rates/latest

$0.01 USDC. Retrieve latest available exchange rates from the Frankfurter API (ECB data). Rates are delayed reference rates, not real-time market rates.

Inputs: base?, symbols?

Docs: https://www.brainiac.software/api/fx/docs#fx-rates-latest

Example request:

```json
{
  "base": "USD",
  "symbols": [
    "EUR",
    "GBP"
  ]
}
```

Example response:

```json
undefined
```

### POST /api/v1/fx/rates/historical

$0.02 USDC. Retrieve exchange rates for a specific date from the Frankfurter API (ECB data). Returns rates for the closest working day.

Inputs: date, base?, symbols?

Docs: https://www.brainiac.software/api/fx/docs#fx-rates-historical

Example request:

```json
{
  "date": "2024-01-01",
  "base": "USD",
  "symbols": [
    "EUR",
    "GBP"
  ]
}
```

Example response:

```json
undefined
```

### POST /api/v1/fx/rates/timeseries

$0.05 USDC. Retrieve exchange rates over a date range from the Frankfurter API (ECB data). Returns rates for each working day in the range.

Inputs: from, to, base?, symbols?

Docs: https://www.brainiac.software/api/fx/docs#fx-rates-timeseries

Example request:

```json
{
  "from": "2024-01-01",
  "to": "2024-01-05",
  "base": "USD",
  "symbols": [
    "EUR",
    "GBP"
  ]
}
```

Example response:

```json
undefined
```

### POST /api/v1/fx/rates/convert

$0.02 USDC. Convert an amount between currencies using delayed reference rates from the Frankfurter API (ECB data). Rates are not real-time market rates.

Inputs: amount, from, to, date?

Docs: https://www.brainiac.software/api/fx/docs#fx-rates-convert

Example request:

```json
{
  "amount": 100,
  "from": "USD",
  "to": "EUR"
}
```

Example response:

```json
undefined
```

### POST /api/v1/fx/currencies/list

$0.01 USDC. Retrieve the list of supported currencies from the Frankfurter API. All currencies are ISO 4217 codes.

Inputs: none

Docs: https://www.brainiac.software/api/fx/docs#fx-currencies-list

Example request:

```json
{}
```

Example response:

```json
undefined
```