Estimate Fee - Finrock

curl --request GET \
     --url 'https://api.finrock.io/dac/v1/estimate-fee?asset=ETH&fee_rate=20' \
     --header 'Authorization: Bearer {JWT}' \
     --header 'accept: application/json' \
     --header 'x-api-key: YOUR_API_KEY'

curl --request GET \
     --url 'https://api.finrock.io/dac/v1/estimate-fee?asset=BTC&amount=0.05&fee_rate=10' \
     --header 'Authorization: Bearer {JWT}' \
     --header 'accept: application/json' \
     --header 'x-api-key: YOUR_API_KEY'

{
  "asset": "ETH",
  "fee": 0.00042000,
  "fee_rate": 20,
  "fee_rate_unit": "GWei"
}

{
  "asset": "BTC",
  "fee": 0.00002250,
  "fee_rate": 10,
  "fee_rate_unit": "Sat/Byte"
}

GET

dac

estimate-fee

curl --request GET \
     --url 'https://api.finrock.io/dac/v1/estimate-fee?asset=ETH&fee_rate=20' \
     --header 'Authorization: Bearer {JWT}' \
     --header 'accept: application/json' \
     --header 'x-api-key: YOUR_API_KEY'

curl --request GET \
     --url 'https://api.finrock.io/dac/v1/estimate-fee?asset=BTC&amount=0.05&fee_rate=10' \
     --header 'Authorization: Bearer {JWT}' \
     --header 'accept: application/json' \
     --header 'x-api-key: YOUR_API_KEY'

{
  "asset": "ETH",
  "fee": 0.00042000,
  "fee_rate": 20,
  "fee_rate_unit": "GWei"
}

{
  "asset": "BTC",
  "fee": 0.00002250,
  "fee_rate": 10,
  "fee_rate_unit": "Sat/Byte"
}

MCP scope: dac.read The Estimate Fee endpoint calculates the expected network fee for a transaction before you submit it. Use this to show fee estimates to end users, validate that a wallet holds sufficient gas, or build fee-inclusive UIs. You supply a fee_rate expressed in the units appropriate for the target blockchain (see the table below), and for UTXO chains you must also supply the amount so the API can calculate transaction size. The response returns the total estimated fee denominated in the blockchain’s native token.

Fee Rate Units by Blockchain

Different blockchains use different units for their fee rate parameter. Use the table below to determine the correct unit for your fee_rate value.

Blockchain	Example Assets	`fee_rate` Unit
UTXO	BTC, LTC, DASH, DOGE, BCH	Sat/Byte
EVM	ETH, BSC, POL, BASE	GWei
Tron	TRX	Sun
Ripple	XRP	Drop
Stellar	XLM	Stroop
Cardano	ADA	Lovelace
Solana	SOL	Lamport

Query Parameters

string

required

The asset for which to estimate the fee. Use the id value from the Supported Assets list (e.g. BTC, ETH, USDT_ETH).

double

The amount to transfer in the asset’s native unit. Required for UTXO chains (BTC, LTC, DASH, DOGE, BCH) because transaction size — and therefore fee — depends on the number of UTXOs selected to fund the transfer. Optional for non-UTXO chains.

float

required

The desired fee rate, expressed in the unit appropriate for the target blockchain (see the table above). For example, pass 20 for 20 GWei on an EVM chain, or 10 for 10 Sat/Byte on Bitcoin.

curl --request GET \
     --url 'https://api.finrock.io/dac/v1/estimate-fee?asset=ETH&fee_rate=20' \
     --header 'Authorization: Bearer {JWT}' \
     --header 'accept: application/json' \
     --header 'x-api-key: YOUR_API_KEY'

curl --request GET \
     --url 'https://api.finrock.io/dac/v1/estimate-fee?asset=BTC&amount=0.05&fee_rate=10' \
     --header 'Authorization: Bearer {JWT}' \
     --header 'accept: application/json' \
     --header 'x-api-key: YOUR_API_KEY'

Response

A successful request returns HTTP 200 with the estimated fee.

string

The asset for which the fee was estimated.

number

The estimated network fee, denominated in the blockchain’s native token. For token assets (e.g. USDT_ETH), the fee is returned in ETH, not in USDT.

number

The fee_rate value used for the estimate, echoed back in the response.

string

The unit of the fee_rate used (e.g. GWei, Sat/Byte).

{
  "asset": "ETH",
  "fee": 0.00042000,
  "fee_rate": 20,
  "fee_rate_unit": "GWei"
}

{
  "asset": "BTC",
  "fee": 0.00002250,
  "fee_rate": 10,
  "fee_rate_unit": "Sat/Byte"
}

Fee estimates are approximate and based on current network conditions at the time of the request. The actual fee deducted when the transaction is confirmed may differ if network congestion changes between the estimate and submission.