Transaction policies are rules that can govern how a transaction is processed, introduced by the transaction parameters that you pass to a transaction request. The available policies are as follows:
Optional amount on the base asset to incentivise block producer to include transaction, ensuring faster processing for those willing to pay more. The value set here will be added to the transaction maxFee.
The maximum byte length allowed for the transaction witnesses array.
The number of blocks that must pass before the transaction can be included in a block.
The maximum amount you're willing to pay for the transaction using the base asset.
The following snippet shows which transaction parameters correspond to which policies:
// #import { ScriptTransactionRequest };
const transactionRequest = new ScriptTransactionRequest({
tip: bn(10), // Sets the tip policy
witnessLimit: bn(1), // Sets the witness limit policy
maturity: 1, // Sets the maturity policy
maxFee: bn(1), // Sets the max fee policy
}); Policies used for a transaction can be retrieved from a transaction using a TransactionResponse. The below snippet will show how to retrieve the policies from a transaction:
// #import { ScriptTransactionRequest, TransactionResponse, Policy };
// Instantiate the transaction request with transaction parameters that would
// set the respective policies.
const transactionRequest = new ScriptTransactionRequest({
script: SumScript.bytecode,
gasLimit: bn(2000),
maturity: 2,
tip: bn(3),
witnessLimit: 900,
maxFee: bn(60_000),
});
// Set the script main function arguments
transactionRequest.setData(SumScript.abi, scriptMainFunctionArguments);
// Fund the transaction
transactionRequest.addResources(resources);
// Submit the transaction and retrieve the transaction response
const tx: TransactionResponse = await wallet.sendTransaction(transactionRequest);
const response = await tx.waitForResult();
// is undefined if the transaction had no policies applied.
const policies: Policy[] | undefined = response.transaction.policies;