The transaction will not be added to the blockchain. Note that the estimate may be significantly more than the amount of gas actually used by the transaction, for a variety of reasons including Klaytn Virtual Machine mechanics and node performance.

📘
Supported on Klaytn (mainnet) only.

Parameters

Request

Name	Type	Description
callObject	Object	The transaction call object. See the next table for the object's properties.

callObject has the following properties:

Name	Type	Description
from	20-byte DATA	(optional) The address the transaction is sent from.
to	20-byte DATA	(optional when testing the deployment of a new contract) The address the transaction is directed to.
gas	QUANTITY	(optional) Integer of the upper gas limit provided for the gas estimation. If no gas limit is specified, the Klaytn node uses the designated gas limit as an upper bound.
gasPrice	QUANTITY	(optional) Integer of the gasPrice used for each paid gas.
value	QUANTITY	(optional) Integer of the value sent with this transaction.
input	DATA	(optional) Hash of the method signature and encoded parameters. It replaces `data` field, but 'data` field is still supported for backward compatibility.

Result

Type	Description
QUANTITY	The amount of gas used.

API Endpoint

The format of a Klaytn API endpoint is
https://open-platform.nodereal.io/{{apiKey}}/klaytn/

Here is an example:
https://open-platform.nodereal.io/4c0a1c23661a4e26bcbcwed461e34ea9/klaytn/

Example

// Request
curl https://open-platform.nodereal.io/{{apiKey}}/klaytn/ \
  -X POST \
  -H "Content-Type: application/json" \
  --data '{"jsonrpc": "2.0", "method": "klay_estimateGas", "params": [{"from": "0x3f71029af4e252b25b9ab999f77182f0cd3bc085", "to": "0x87ac99835e67168d4f9a40580f8f5c33550ba88b", "gas": "0x100000", "gasPrice": "0x5d21dba00", "value": "0x0", "input": "0x8ada066e"}], "id": 1}'

// Result
{
  "jsonrpc": "2.0","id":1,
  "result": "0x5208" // 21000
}