Fuels-ts

Appearance

Transaction Policies ​

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:

Tip ​

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.

Witness Limit ​

The maximum byte length allowed for the transaction witnesses array.

Maturity ​

The number of blocks that must pass before the transaction can be included in a block.

Max Fee ​

The maximum amount you're willing to pay for the transaction using the base asset.

Setting Transaction Policies ​

The following snippet shows which transaction parameters correspond to which policies:

ts
import { bn, ScriptTransactionRequest } from 'fuels';

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
});
See code in context

Retrieving Transaction Policies from a Transaction ​

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:

ts
import type { Policy } from 'fuels';
import { Provider, Wallet, ScriptTransactionRequest, bn } from 'fuels';

import { LOCAL_NETWORK_URL, WALLET_PVT_KEY } from '../../env';
import { ScriptSum } from '../../typegend';

const provider = await Provider.create(LOCAL_NETWORK_URL);
const wallet = Wallet.fromPrivateKey(WALLET_PVT_KEY, provider);

/**
 * Instantiate the transaction request with transaction parameters
 * that will set the respective policies.
 */
const transactionRequest = new ScriptTransactionRequest({
  script: ScriptSum.bytecode,
  gasLimit: bn(2000),
  tip: bn(10),
  witnessLimit: 900,
  maxFee: bn(2000),
});

// Set the script main function arguments
const scriptArguments = [1];
transactionRequest.setData(ScriptSum.abi, scriptArguments);

// Fund the transaction
const resources = await wallet.getResourcesToSpend([
  { amount: 1000, assetId: provider.getBaseAssetId() },
]);

transactionRequest.addResources(resources);

// Submit the transaction and retrieve the transaction response
const tx = await wallet.sendTransaction(transactionRequest);
const response = await tx.waitForResult();
const policies: Policy[] | undefined = response.transaction.policies;

console.log('policies', policies);
See code in context