Note: The estimate may be significantly more than the amount of gas actually used by the transaction, for a variety of reasons including EVM mechanics and node performance. Estimates are served directly from nodes, we're not doing anything special to the value so the rest of the network is likely seeing the same.

Parameters

Object - The transaction call object
- from: DATA, 20 Bytes - (optional) The address the transaction is sent from.
- to: DATA, 20 Bytes - The address the transaction is directed to.
- gas: QUANTITY - (optional) Integer of the gas provided for the transaction execution. eth_estimateGas consumes zero gas, but this parameter may be needed by some executions. NOTE: this parameter has a cap of 50 Million gas per request
- gasPrice: QUANTITY - (optional) Integer of the gasPrice used for each paid gas. Note: most of our users (95%+) never set the gasPrice on eth_call.
- value: QUANTITY - (optional) Integer of the value sent with this transaction
- data: DATA - (optional) Hash of the method signature and encoded parameters. For details see Ethereum Contract ABI
QUANTITY|TAG - Integer block number, or the string "latest", "earliest" or "pending", see the default block parameter.

NOTE：

eth_estimateGas** **will check the balance of the sender (to make sure that the sender has enough gas to complete the request). This means that even though the call doesn't consume any gas, the from address must have enough gas to execute the transaction.

If no gas is specified geth uses the block gas limit from the pending block as an upper bound. As a result the returned estimate might not be enough to executed the call/transaction when the amount of actual gas needed is higher than the pending block gas limit.

Returns

QUANTITY - The amount of gas used.

Example

Request

curl https://opt-mainnet.unifra.io/v1/your-api-key \
-X POST \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","method":"eth_estimateGas","params":[{see above}],"id":1}'

URL: https://opt-mainnet.unifra.io/v1/your-api-key
RequestType: POST
Body:
{
    "jsonrpc":"2.0",
    "method":"eth_estimateGas",
    "params":[{see above}],
    "id":1
}

Result

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