Icon LinkCombining UTXOs

When performing a funding operation or calling getResourcesToSpend, you may encounter the INSUFFICIENT_FUNDS_OR_MAX_COINS error if the number of coins fetched per asset exceeds the maximum limit allowed by the chain.

You may also want to do this if you want to reduce the number of inputs in your transaction, which can be useful if you are trying to reduce the size of your transaction or you are receiving the MAX_INPUTS_EXCEEDED error.

Icon LinkUsing the Account's consolidateCoins Method

The SDK provides a built-in method to consolidate your base asset UTXOs:

const baseAssetId = await provider.getBaseAssetId();
 
// By default, this will combine UTXOs into a single output (outputNum = 1)
const result = await wallet.consolidateCoins({
  assetId: baseAssetId,
  // Optional: 'parallel' (default) or 'sequential' execution mode
  mode: 'parallel',
  // Optional: number of output UTXOs to create (default is 1)
  outputNum: 1,
});
 
// Check the transaction results and any errors
console.log('Successful transactions:', result.txResponses);
console.log('Failed transactions:', result.errors);
 
// Verify the reduced number of UTXOs
const { coins: consolidatedCoins } = await wallet.getCoins(baseAssetId);
console.log('Consolidated Coins Length', consolidatedCoins.length);

Icon LinkConfiguration Options

The consolidateCoins method accepts the following parameters:

• assetId: The ID of the asset to consolidate (currently supports only the base asset)
• mode (optional): How to submit consolidation transactions
  • 'parallel' (default): Submit all transactions simultaneously for faster processing
  • 'sequential': Submit transactions one after another, waiting for each to complete
• outputNum (optional): Number of output UTXOs to create (default is 1)

Icon LinkLimitations

• Currently only supports consolidating the base asset

Icon LinkMax Inputs and Outputs

It's also important to note that depending on the chain configuration, you may be limited on the number of inputs and/or outputs that you can have in a transaction. These amounts can be queried via the TxParameters Icon Link GraphQL query.

import { Provider } from 'fuels';
 
import { LOCAL_NETWORK_URL } from '../../../env';
 
const provider = new Provider(LOCAL_NETWORK_URL);
 
const { maxInputs, maxOutputs } = (await provider.getChain())
  .consensusParameters.txParameters;