# Price conversion


Conversion is informational. It never changes what is credited, charged or paid out: those amounts are always exact integer units of the token.

## Endpoints

- `GET /convert/?value=&from=&to=` converts between any two supported currencies.
- `GET /{ticker}/convert/?value=&from=` converts into the ticker's own asset, using its decimals.

Both are described with examples in the [API reference](api-reference.md).

`from` and `to` are case-insensitive. `value` is a positive plain decimal with at most 30 integer and 18 fraction digits (no sign, exponent or separators).

## Supported currencies

Fiat currencies: `usd`, `eur`, `gbp`, `cad`, `jpy`, `aed`, `myr`, `idr`, `thb`, `chf`, `sgd`, `rub`, `zar`, `try`, `lkr`, `ron`, `bgn`, `huf`, `czk`, `php`, `pln`, `ugx`, `mxn`, `inr`, `hkd`, `cny`, `brl`, `dkk`, `twd`, `aud`, `ngn`, `sek`, `nok`, `uah`, `vnd`.

Priced assets: `bnb`, `btc`, `eth`, `trx`, `usdc`, `usdt`.

## Rounding

- Fiat results are rounded half up to 2 decimals. Token results are rounded half up to the asset's decimals.
- `exchange_rate` is the number of `to` units per one `from` unit, rounded half up to 12 decimals with trailing zeros trimmed.

## Freshness and failure

Prices come from CoinGecko and are cached for a short time. If no fresh price exists, or conversion is disabled, the endpoints answer HTTP `503` with `{"status":"error","error":"Price data is temporarily unavailable"}`. They never return a stale or guessed value.

## In callbacks

- Every callback carries `price`, the USD price of one whole token with up to 8 decimals, when a fresh price existed at event creation.
- Confirmed callbacks of orders created with `convert=1` also carry `value_coin_convert` and `value_forwarded_coin_convert`. They are JSON objects serialized as strings, keyed by upper-case fiat code with 2-decimal values, for example `{"EUR":"90.00","USD":"100.02"}`.
- Without a fresh price the callback is still sent on time, without `price` and the convert fields. They are never added later.
- `convert=1` is refused with HTTP `400` at create when conversion is disabled.