Paying for Sui Transactions with Gas Coins
With Programmable Transaction blocks, you can use the gas payment coin to construct coins with a set
splitCoin. This is useful for Sui payments, and avoids the need for up-front coin
selection. You can use
txb.gas to access the gas coin in a transaction block, and it is valid as
input for any arguments, as long as it is used
by-reference (opens in a new tab).
Practically speaking, this means you can also add to the gas coin with
mergeCoins and borrow it
for Move functions with
You can also transfer the gas coin using
transferObjects, in the event that you want to transfer
all of your coin balance to another address.
The new transaction builder comes with default behavior for all gas logic, including automatically setting the gas price, budget, and selecting coins to be used as gas. This behavior can be customized.
By default, the gas price is set to the reference gas price of the network. You can also explicitly
set the gas price of the transaction block by calling
setGasPrice on the transaction builder.
By default, the gas budget is automatically derived by executing a dry-run of the transaction block
beforehand. The dry run gas consumption is then used to determine a balance for the transaction. You
can override this behavior by explicitly setting a gas budget for the transaction, by calling
setGasBudget on the transaction builder.
Note: The gas budget is represented in Sui, and should take the gas price of the transaction block into account.
By default, the gas payment is automatically determined by the SDK. The SDK selects all of the users coins that are not used as inputs in the transaction block.
The list of coins used as gas payment will be merged down into a single gas coin before executing the transaction block, and all but one of the gas objects will be deleted. The gas coin at the 0-index will be the coin that all others are merged into.
// you need to ensure that the coins do not overlap with any
// of the input objects for the transaction block