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eth_estimateGas

Generate and return an amount of gas that, if supplied at the queried block, would allow a transaction to avoid an out of gas error.

Note that:

  • This is likely to be an overestimate (perhaps a large one).
  • The transaction may run out of gas in any event - because the block at which it will be executed cannot be known when eth_estimateGas() is called.
  • The transaction may not succeed in any case - all we guarantee is that it won't run out of gas. It might revert or halt (due to eg. an invalid opcode).

Parameters

Transaction

Parameter Type Required Description
from string required The address of the sender of this message call
to string optional The recipient address
gas string optional Gas to give this message call, as a hex number in a string
gas_price string optional Gas price to give this message call as a hex number in a string
data string required The calldata
value string optional Value to send with this call, as a hex number in a string. Assumed 0 if not given.

Block Number

The block number can be:

  • A hex number in a string: eg. "0x800"
  • A block hash as a string eg. "0xf77e76c25038b0be1fbd12a4f3e404173802bf0c9a9e62deef7949201d59ebfb
  • "earliest" for the earliest block
  • "latest" for the latest block
  • "safe" for the last block known to be safe.
  • "finalized" for the latest finalized block - in Zilliqa 2 this is the same as the safe block.
  • "pending" is a synonym for latest.

If the block number is not provided, latest is assumed.

Example Request

curl -d '{
 "id": "1",
 "jsonrpc": "2.0",
 "method": "eth_estimateGas",
 "params": [ {
     "from": "0xcb57ec3f064a16cadb36c7c712f4c9fa62b77415",
     "to": "0x55c3E57617B87c0e24d66b3eB4860a87bFeeF25A",
     "gas": "0x100000",
     "gas_price": "0x1",
     "value": "0x0",
     "data": "0x85bb7d69" },  "latest"
]}' -H "Content-Type: application/json" -X POST "https://api.zq2-prototestnet.zilliqa.com/"

Example response

{"jsonrpc":"2.0","result":"0x543d","id":"1"}

Arguments

Parameter Type Required Description
id string Required "1"
jsonrpc string Required "2.0"
method string Required "DSBlockListing"
params array Requred [ transaction ] or [transaction, block_number]