Configuration

Swap Service Configuration

The VeloraProtocolEvm accepts a configuration object that defines fee controls and behavior:

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

// Create wallet account first
const account = new WalletAccountEvm(seedPhrase, "0'/0/0", {
  provider: 'https://ethereum-rpc.publicnode.com'
})

// Create swap service with configuration
const swapProtocol = new VeloraProtocolEvm(account, {
  swapMaxFee: 200000000000000n // Optional: Max swap fee in wei
})

The swap service uses the wallet account configuration for network access and signing. The account must expose an EVM-compatible JSON-RPC URL or EIP-1193 provider; a generic interface type does not make a non-EVM account compatible with this module:

import { WalletAccountEvm, WalletAccountReadOnlyEvm } from '@tetherto/wdk-wallet-evm'

// Full access account
const account = new WalletAccountEvm(
  seedPhrase,
  "0'/0/0",
  {
    provider: 'https://ethereum-rpc.publicnode.com'
  }
)

// Read-only account (quotes only)
const readOnly = new WalletAccountReadOnlyEvm(
  '0xYourAddress',
  {
    provider: 'https://ethereum-rpc.publicnode.com'
  }
)

// Create swap service
const swapProtocol = new VeloraProtocolEvm(account, {
  swapMaxFee: 200000000000000n
})

Configuration Options

Swap Max Fee

The swapMaxFee option sets an upper bound for total gas costs to prevent excessive fees.

Type: bigint (optional)
Unit: Wei

Examples:

const config = {
  // Cap total gas fee to 0.0002 ETH (in wei)
  swapMaxFee: 200000000000000n,
}

// Usage example
try {
  const result = await swapProtocol.swap({
    tokenIn: '0xdAC17F958D2ee523a2206206994597C13D831ec7', // USDt (6 decimals)
    tokenOut: '0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2', // WETH (18 decimals)
    tokenInAmount: 1000000n
  })
} catch (error) {
  if (error.message.includes('max fee')) {
    console.error('Swap stopped: Fee too high')
  }
}

ERC‑4337 (Account Abstraction) Configuration

When using ERC‑4337 smart accounts (@tetherto/wdk-wallet-evm-erc-4337), you can override fee behavior per swap and specify a paymaster token:

import { WalletAccountEvmErc4337 } from '@tetherto/wdk-wallet-evm-erc-4337'

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

const swapAA = new VeloraProtocolEvm(aa, { swapMaxFee: 200000000000000n })

const result = await swapAA.swap({
  tokenIn: '0xTokenIn',
  tokenOut: '0xTokenOut',
  tokenInAmount: 1000000n
}, {
  paymasterToken: {
    address: '0xdAC17F958D2ee523a2206206994597C13D831ec7'
  },
  swapMaxFee: 200000000000000n // Per‑swap override
})

Per-call ERC‑4337 Config

The second argument to swap() and quoteSwap() accepts ERC‑4337 wallet config overrides only when the protocol uses the concrete WalletAccountEvmErc4337 or WalletAccountReadOnlyEvmErc4337 class, respectively. Use it to switch paymaster token, sponsorship policy, or native-coin fee behavior for a single call. swap() also accepts swapMaxFee as a per-swap fee cap. Standard EVM accounts use one ordinary EVM transaction and do not apply these per-call ERC‑4337 overrides.

Type: partial ERC‑4337 wallet config (optional)

Example:

const result = await swapAA.swap({
  tokenIn: '0xdAC17F...ec7',
  tokenOut: '0xC02a...6Cc2', // WETH
  tokenInAmount: 1000000n
}, {
  paymasterToken: {
    address: '0xdAC17F958D2ee523a2206206994597C13D831ec7'
  },
  swapMaxFee: 200000000000000n
})

Network Support

velora supports multiple EVM networks (e.g., Ethereum, Polygon, Arbitrum). Ensure your account is configured with a valid provider for the target network.

// Ethereum Mainnet
const eth = new WalletAccountEvm(seedPhrase, "0'/0/0", {
  provider: 'https://ethereum-rpc.publicnode.com'
})

// Polygon
const polygon = new WalletAccountEvm(seedPhrase, "0'/0/0", {
  provider: 'https://polygon-bor-rpc.publicnode.com'
})

Swap Options

When calling swap, provide the swap parameters:

const swapOptions = {
  tokenIn: '0xTokenIn',          // ERC‑20 to sell
  tokenOut: '0xTokenOut',        // ERC‑20 to buy
  tokenInAmount: 1000000n,       // exact input (base units)
  // OR
  // tokenOutAmount: 1000000n,   // exact output (base units)
  to: '0xRecipient'              // optional recipient (defaults to your address)
}

const result = await swapProtocol.swap(swapOptions)