Execute Swaps

This guide explains how to run a basic exact-input swap, an exact-output swap, and a swap from an ERC-4337 smart account. You should already have a VeloraProtocolEvm instance.

Swaps spend tokens and gas on-chain. Before execution, approve the input token for the current Velora spender on the account's chain. The module does not submit approvals or reset allowances. See configuration for approval and fee prerequisites.

Basic exact-input swap

You can sell an exact amount of the input token using swap():

Exact input: USDt to WETH

const result = await swapProtocol.swap({
  tokenIn: '0xdAC17F958D2ee523a2206206994597C13D831ec7',
  tokenOut: '0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2',
  tokenInAmount: 1000000n
})

console.log('Swap transaction hash:', result.hash)
console.log('Total fee (account units):', result.fee)
console.log('Tokens sold (base units):', result.tokenInAmount)
console.log('Tokens bought (base units):', result.tokenOutAmount)

Exact output swap

You can receive an exact amount of the output token by passing tokenOutAmount to swap():

Exact output amount

const result = await swapProtocol.swap({
  tokenIn: '0xdAC17F958D2ee523a2206206994597C13D831ec7',
  tokenOut: '0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2',
  tokenOutAmount: 500000000000000000n
})

console.log('Swap hash:', result.hash)
console.log('Tokens sold (base units):', result.tokenInAmount)
console.log('Tokens bought (base units):', result.tokenOutAmount)

Swap with ERC-4337

You can perform a user-operation-backed swap by constructing VeloraProtocolEvm with WalletAccountEvmErc4337 and passing paymaster options to swap():

Swap with smart account and paymaster

import { WalletAccountEvmErc4337 } from '@tetherto/wdk-wallet-evm-erc-4337'
import VeloraProtocolEvm from '@tetherto/wdk-protocol-swap-velora-evm'

const aa = new WalletAccountEvmErc4337(seedPhrase, "0'/0/0", {
  chainId: 1,
  provider: 'https://ethereum-rpc.publicnode.com',
  bundlerUrl: process.env.BUNDLER_URL,
  paymasterUrl: process.env.PAYMASTER_URL,
  paymasterAddress: process.env.PAYMASTER_ADDRESS,
  safeModulesVersion: '0.3.0',
  paymasterToken: {
    address: '0xdAC17F958D2ee523a2206206994597C13D831ec7'
  }
})

// Exclusive cap: 0.01 USDt with this six-decimal paymaster token.
const swapAA = new VeloraProtocolEvm(aa, { swapMaxFee: 10000n })

const result = await swapAA.swap({
  tokenIn: '0xdAC17F958D2ee523a2206206994597C13D831ec7',
  tokenOut: '0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2',
  tokenInAmount: 1000000n
}, {
  paymasterToken: {
    address: '0xdAC17F958D2ee523a2206206994597C13D831ec7'
  },
  swapMaxFee: 10000n
})

console.log('Swap hash:', result.hash)
console.log('Total fee (USDt base units):', result.fee)

Token addresses must match the chain your account uses (for example, Ethereum USD₮ and Arbitrum USD₮0 use different contract addresses).

Next Steps

Get swap quotes before sending
Handle errors
Get started if you still need setup

Execute Swaps

Basic exact-input swap

Exact output swap

Swap with ERC-4337

Next Steps

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