Dust sweep

import {
  createComposeSdk,
  materialisers,
  resources,
} from '@lifi/composer-sdk';

const USDC = '0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48';
const USDT = '0xdAC17F958D2ee523a2206206994597C13D831ec7';

const sdk = createComposeSdk({ baseUrl: 'https://composer.li.quest' });

const builder = sdk.flow(1, {
  name: 'dust-sweep',
  inputs: {
    amountIn: resources.erc20(USDC, 1),
  },
});

// Split USDC 80/20.
// Only the 80% portion (`a`) is consumed by the swap.
// The 20% portion (`b`) is intentionally left unbound — it stays on
// the proxy as dust and gets swept back to the sender.
const { a } = builder.core.split('split', {
  bind: { source: builder.inputs.amountIn },
  config: { bps: 8000 },
});

// Swap only the 80% portion to USDT.
builder.lifi.swap('swap', {
  bind: { amountIn: a },
  config: {
    resourceOut: resources.erc20(USDT, 1),
    slippage: 0.03,
  },
});

// sweepTo ensures the unused 20% USDC is transferred back to the
// sender rather than being stranded on the proxy.
// See /composer/composer-api/concepts/sweeping-and-amounts for the full semantics.
const result = await builder.compile({
  signer: '0xYourSignerAddress',
  inputs: {
    amountIn: materialisers.directDeposit({ amount: '10000000' }), // 10 USDC
  },
  sweepTo: builder.context.sender,
});