Estimate Blockchain Fees

Returns an estimated network fee required to forward funds for a given ticker. This value is an approximation and may vary depending on current blockchain conditions. For token tickers (e.g. erc20/usdt, trc20/usdt) the fee is estimated in the network fee coin (e.g. ETH for ERC-20, TRX for TRC-20).

GET https://api.kingpay.online/{ticker}/estimate/

Use a supported token ticker, such as erc20/usdt or trc20/usdt. Estimates for native coin tickers such as btc and ltc are currently unavailable.

Notices

Uses the stored network fee estimate, multiplied by the destination count and priority factor (economic: 0.9, default: 1, fast: 1.2). It does not calculate a fresh blockchain transaction or the final payment's network_fee deduction.
Missing, zero or invalid fee estimates return status: "error" with Network fee estimate unavailable.
addresses must be a positive integer (default: 1). priority must be economic, default or fast (default: default). Invalid or empty values return an error.
This endpoint returns an estimate only. Actual fees can be higher or lower depending on network congestion and confirmation priority.
The addresses parameter increases the estimate proportionally, because it models multiple forwarding destinations.
For token tickers the fee is always returned in the network fee coin (for example, ERC-20 tokens are charged in ETH, TRC-20 tokens in TRX).
Fiat conversions in estimated_cost_currency are derived from internal USD pricing when available.
If the ticker is unknown, the endpoint returns an error JSON with status: "error".

Path parameters

ticker string • required

Identifies the cryptocurrency and (optionally) the token network this request refers to.

erc20/usdt — USDT on Ethereum (ERC-20).
trc20/usdt — USDT on TRON (TRC-20).

Example: https://api.kingpay.online/trc20/usdt/estimate/

Query parameters

addresses integer • optional default: 1

Number of forwarding destinations to include in the estimation. The estimate scales with this value.

Example: https://api.kingpay.online/erc20/usdt/estimate/?addresses=3

priority string • optional default: "default"

Affects the estimation by applying a multiplier that approximates confirmation speed.

economic — lower cost estimate.
default — standard estimate.
fast — higher cost estimate.

Example: https://api.kingpay.online/trc20/usdt/estimate/?priority=fast

Response fields

{
  "status": "success",
  "estimated_cost": "0.0001141312887",
  "estimated_cost_currency": {
    "USD": "0.36",
    "EUR": "0.33",
    "PLN": "1.42"
  }
}

status — "success" on success or "error" if the ticker was not found.
estimated_cost — estimated network fee in the network fee coin (string). For token tickers this is not the token amount, but the coin used to pay fees (e.g. ETH, TRX, BNB).
estimated_cost_currency — optional object mapping fiat currency codes (e.g. USD, EUR, PLN) to string amounts derived from the internal USD price. May be an empty object if price data is not available.
addresses and priority affect the estimate by scaling the base fee. They do not represent exact on-chain rules, only the service’s estimation policy.

Error example

If an invalid or unsupported ticker is requested, the endpoint responds with:

{
  "status": "error",
  "error": "Invalid ticker"
}