Fast Transfers

import { createNearBuilder } from "@omni-bridge/near"
import type { FastFinTransferParams } from "@omni-bridge/near"

const nearBuilder = createNearBuilder({ network: "mainnet" })

const params: FastFinTransferParams = {
  tokenId: "wrap.near",
  amount: "1000000000000000000000000",      // Original amount
  amountToSend: "990000000000000000000000", // Amount minus fee
  transferId: {
    origin_chain: "Eth",
    origin_nonce: 12345n,
  },
  recipient: "near:recipient.near",
  fee: {
    fee: "10000000000000000000000",  // Token fee
    native_fee: "0",
  },
  msg: "",
  storageDepositAmount: "1250000000000000000000",
  relayer: "relayer.near",
}

const tx = nearBuilder.buildFastFinTransfer(params, "relayer.near")

const originalAmount = 1000n * 10n**24n  // 1000 tokens
const fee = 10n * 10n**24n               // 10 tokens (1%)
const amountToSend = originalAmount - fee // 990 tokens

// Relayer fronts 990 tokens
// Relayer claims 1000 tokens after finalization
// Profit: 10 tokens

function shouldExecuteFastTransfer(transfer: PendingTransfer): boolean {
  // 1. Verify transfer exists on source chain
  if (!await verifyTransferOnSource(transfer)) return false
  
  // 2. Check not already finalized
  if (await isAlreadyFinalized(transfer.transferId)) return false
  
  // 3. Verify fee covers gas + profit margin
  const gasCost = await estimateGasCost()
  if (transfer.fee <= gasCost) return false
  
  // 4. Check liquidity
  if (!hasLiquidity(transfer.tokenId, transfer.amountToSend)) return false
  
  // 5. Validate recipient
  if (!isValidAddress(transfer.recipient)) return false
  
  return true
}

const requiredLiquidity = {
  "wrap.near": 100_000n * 10n**24n,  // 100k wNEAR
  "usdc.near": 500_000n * 10n**6n,   // 500k USDC
  "usdt.near": 500_000n * 10n**6n,   // 500k USDT
}