Get transaction fees

How to get the gas fee for a specific transaction such as an NFT Transfer, Token Transfer, Contract Execution, etc.

The cost of a specific transaction on the blockchain is dependent on the complexity of that transaction. The complexity of a transaction is expressed in the amount of "gas" that is required to execute this transaction. A more complex transaction requires a higher gas amount.

This means that the fee that needs to be paid for a specific transaction is the following:

fee-for-a-transaction = amount-of-gas-needed * gas-price-at-that-moment

This endpoint adds all the necessary details to a generic transaction request, like the necessary GAS fees, etc.

To retrieve the gas needed to execute a certain blockchain transaction, the build transaction endpoint can be used.

Request Endpoint: reference

POST https://api-wallet.venly.io/api/transactions/build

Example Request:

POST https://api-wallet.venly.io/api/transactions/build
{
    "type": "TRANSFER",
    "secretType": "MATIC",
    "walletId": "2b358962-4467-4f41-ab93-2b6395d8ae16",
    "to": "0x2Eaf85AF290759770CF98BF83aa640DC2A63daDf",
    "value": 10
}

Response Body:

{
    "success": true,
    "result": {
        "walletId": "2b358962-4467-4f41-ab93-2b6395d8ae16",
        "gasPrice": 20000000000,
        "gas": 21000,
        "value": 10000000000000000000,
        "to": "0x2Eaf85AF290759770CF98BF83aa640DC2A63daDf",
        "type": "MATIC_TRANSACTION"
    }
}

๐Ÿ“˜

  • gas represents the maximum amount of gas you allow to be spent on this transaction
  • gasPrice is the price for one unit of gas

๐Ÿ“˜

The gasPrice is return in Wei. One ETH equals 10e18 wei.

The gas fee is calculated by gas limit x gas price per unit. So, if the gas limit is 20,000 and the gas price per unit is 200, then the calculation would be 20,000 x 200 = 4,000,000 gwei. We mentioned above that one gwei is equal to 0.000000001 ETH. So, this transaction cost would be approximately 0.004 ETH.

Transaction Request Examples

The following transaction types can be used when building a transaction:

TRANSFER

{
    "type": "TRANSFER",
    "secretType": "MATIC",
    "walletId": "2b358962-4467-4f41-ab93-2b6395d8ae16",
    "to": "0x2Eaf85AF290759770CF98BF83aa640DC2A63daDf",
    "value": 10
}

GAS_TRANSFER

 {
    "type": "GAS_TRANSFER",
    "secretType": "MATIC",
    "walletId": "2b358962-4467-4f41-ab93-2b6395d8ae16",
    "to": "0x2Eaf85AF290759770CF98BF83aa640DC2A63daDf",
    "value": 10
}

TOKEN_TRANSFER

{
    "type": "TOKEN_TRANSFER",
    "secretType": "ETHEREUM",
    "tokenAddress": "0x07865c6e87b9f70255377e024ace6630c1eaa37f",
    "walletId": "2b358962-4467-4f41-ab93-2b6395d8ae16",
    "to": "0x2Eaf85AF290759770CF98BF83aa640DC2A63daDf",
    "value": 1
}

NFT_TRANSFER

{
    "type": "NFT_TRANSFER",
    "secretType": "ETHEREUM",
    "tokenAddress": "0x77f57f9ac6c52ce5aa9d19a57d0aee82be7e73f9",
    "walletId": "2b358962-4467-4f41-ab93-2b6395d8ae16",
    "to": "0x2Eaf85AF290759770CF98BF83aa640DC2A63daDf",
    "tokenId": 1
}

CONTRACT_EXECUTION

{
    "type": "CONTRACT_EXECUTION",
	"walletId": "2b358962-4467-4f41-ab93-2b6395d8ae16",
	"to": "0xdc71b72db51e227e65a45004ab2798d31e8934c9",
	"secretType": "ETHEREUM",
	"functionName": "transfer",
	"value": 1,
	"inputs": [{
		"type": "address",	
    	"value": "0x80cbb6c4342948e5be81987dce8251dbedd69138"
	}, {
		"type": "uint256",
		"value": 73680000
	}]
}