Coins and amounts

In PS Wallet Pay, each coin is identified by a code, and amounts are passed as strings with a decimal point. This page covers which codes exist, how many decimal places they have, and how USDT without a specified network and fiat invoices work.

#Coin codes

In addition, there is the USDT code — USDT on any network (see below) — and the fiat currencies for the invoice price: USD and RUB, each with 2 decimal places.

#Where each code can be used

The code is case-insensitive: usdt-trc20 and USDT-TRC20 are the same.

#USDT without a specified network

In invoices you can specify just USDT. The user will then be able to pay from any of their USDT accounts — TRC20, BEP20, ERC20, or TON — and the funds will arrive in the app balance on the network the user paid from. The payment network is indicated in the paid_asset field of the paid invoice.

If you need a specific network, specify its code, for example USDT-TRC20: the invoice can then be paid only from that account.

In transfer and createCheck the USDT code is also allowed: the funds are debited from the first network where the app balance has enough, in the order TRC20 → BEP20 → TON → ERC20. If no network has enough, the INSUFFICIENT_FUNDS error is returned. The recipient receives the funds on the same network — it is indicated in the asset field of the response.

#Invoices in dollars and rubles

An invoice can be issued in dollars (USD) or rubles (RUB): to do this, pass currency_type=fiat and fiat. The user chooses what to pay with from the allowed coins (accepted_assets). The amount due is recalculated at the exchange rate at the time of payment and rounded up to the smallest unit of the coin.

By default, a fiat invoice accepts USDT, TRX, BNB, ETH, GRAM, and RUB (of these, those that are currently available). XAUT is not on this list — to accept it, list the coins in accepted_assets explicitly.

The rates used to recalculate fiat invoices are returned by getExchangeRates. The actual payment rate is saved in the invoice in the paid_fiat_rate and paid_usd_rate fields.

#Rubles

Currently, an invoice cannot be paid from a ruble account, and rubles cannot be sent to other users:

• asset=RUB in createInvoice returns the PARAM_ASSET_INVALID error;
• RUB in accepted_assets is ignored at payment, and if RUB is the only item in the list, the PARAM_ACCEPTED_ASSETS_INVALID error is returned;
• asset=RUB in transfer and createCheck returns the 403 TEMPORARILY_UNAVAILABLE error.

However, the invoice price can be specified in rubles (currency_type=fiat, fiat=RUB) — the user will pay with another coin.

#Amount format

Amounts are passed and returned as strings with a decimal point: "12.5", "0.000001".

• In JSON you can also pass a number, but with no more decimal places than the coin has. For example, 12.5000001 for USDT (6 decimal places) causes the PARAM_AMOUNT_INVALID error; there is no rounding.
• The amount must be greater than zero, with no sign, spaces, or thousands separators, and no more than 15 digits before the decimal point.
• Trailing zeros are not counted as extra decimal places: "12.500000000" for USDT is 12.5.
• In responses, extra zeros are dropped: "12.5", not "12.500000".