Bridging

npm install ethers

npm install @solana/web3.js

npm install @solana/web3.js @hyperlane-xyz/sdk @hyperlane-xyz/registry @hyperlane-xyz/utils

import { StarkZap } from "starkzap";

const sdk = new StarkZap({
  network: "mainnet",
  bridging: {
    ethereumRpcUrl: "https://eth-mainnet.g.alchemy.com/v2/<key>",
    solanaRpcUrl: "https://solana-mainnet.g.alchemy.com/v2/<key>",
    layerZeroApiKey: "<layerzero-key>", // required for OFT/OFT-migrated routes
    layerswapApiKey: "<layerswap-key>", // required for Layerswap routes + token discovery
    layerswapBaseUrl: "https://api.layerswap.io", // optional; this is the default
    layerswapAllowedContracts: [], // Starknet contracts Layerswap may call besides the token; see below
  },
});

import { ExternalChain } from "starkzap";

// All bridgeable tokens for current Starknet environment
const allTokens = await sdk.getBridgingTokens();

// Filter by source chain
const ethereumTokens = await sdk.getBridgingTokens(ExternalChain.ETHEREUM);
const solanaTokens = await sdk.getBridgingTokens(ExternalChain.SOLANA);

import { ConnectedEthereumWallet, ExternalChain } from "starkzap";

const evmProvider = window.ethereum;
const [evmAddress] = await evmProvider.request({ method: "eth_requestAccounts" });
const evmChainId = await evmProvider.request({ method: "eth_chainId" }); // "0x1" or "0xaa36a7"

const ethWallet = await ConnectedEthereumWallet.from(
  {
    chain: ExternalChain.ETHEREUM,
    provider: evmProvider,
    address: evmAddress,
    chainId: evmChainId, // evm wallet's chain id
  },
  wallet.getChainId() // starknet wallet's chain id
);

import { ConnectedSolanaWallet, ExternalChain } from "starkzap";

const solWallet = await ConnectedSolanaWallet.from(
  {
    chain: ExternalChain.SOLANA,
    provider: solanaProvider, // must implement signAndSendTransaction()
    address: solanaAddress,
    chainId: solanaChainId, // mainnet / testnet / devnet genesis hash from wallet adapter
  },
  wallet.getChainId()
);

import { Amount, fromAddress } from "starkzap";

const token = ethereumTokens[0];
if (!token) throw new Error("No bridge token available");

// 1) Source-chain available balance
const available = await wallet.getDepositBalance(token, ethWallet);

// 2) ERC20 allowance (null for native/non-allowance routes)
const allowance = await wallet.getAllowance(token, ethWallet);

// 3) Fee estimation (fastTransfer only applies to CCTP)
const fees = await wallet.getDepositFeeEstimate(token, ethWallet, {
  fastTransfer: true,
});

// 4) Submit deposit tx on source chain
const recipient = fromAddress(
  "0x0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
); // Starknet recipient

const tx = await wallet.deposit(
  recipient,
  Amount.parse("25", token.decimals, token.symbol),
  token,
  ethWallet,
  { fastTransfer: true }
);

console.log(tx.hash);

import { Amount, fromAddress } from "starkzap";

const token = ethereumTokens[0];
if (!token) throw new Error("No bridge token available");

const recipient = "0xYourEthereumAddress"; // L1 recipient

// 1) L2 balance available to withdraw
const balance = await wallet.getWithdrawBalance(token, ethWallet);

// 2) Estimate L2 fee for initiating the withdrawal
const fees = await wallet.getInitiateWithdrawFeeEstimate(token, ethWallet, {
  protocol: "cctp",
  fastTransfer: true,
});

// 3) Submit the Starknet burn/initiate transaction
const tx = await wallet.initiateWithdraw(
  recipient,
  Amount.parse("25", token.decimals, token.symbol),
  token,
  ethWallet,
  { protocol: "cctp", fastTransfer: true }
);

console.log(tx.hash);

// Poll until the withdrawal is ready to claim
const result = await wallet.monitorWithdrawal(token, tx.hash);

if (result.protocol === "cctp" && result.attestation && result.message) {
  // Estimate the L1 gas cost before submitting
  const l1Fee = await wallet.getCompleteWithdrawFeeEstimate(
    Amount.parse("25", token.decimals, token.symbol),
    recipient,
    token,
    ethWallet,
    {
      protocol: "cctp",
      attestation: result.attestation,
      message: result.message,
      nonce: result.nonce,
      expirationBlock: result.expirationBlock,
    }
  );

  // Submit the L1 completion transaction
  const l1Tx = await wallet.completeWithdraw(
    recipient,
    Amount.parse("25", token.decimals, token.symbol),
    token,
    ethWallet,
    {
      protocol: "cctp",
      attestation: result.attestation,
      message: result.message,
      nonce: result.nonce,
      expirationBlock: result.expirationBlock,
    }
  );

  console.log(l1Tx.hash);
}

const fees = await wallet.getInitiateWithdrawFeeEstimate(token, ethWallet, {
  protocol: "canonical",
  autoWithdraw: true,
});

await wallet.initiateWithdraw(
  recipient,
  Amount.parse("25", token.decimals, token.symbol),
  token,
  ethWallet,
  {
    protocol: "canonical",
    autoWithdraw: true,
    preferredFeeToken: fees.autoWithdrawFee?.token,
  }
);

// Withdrawal state: "PENDING" | "READY_TO_CLAIM" | "COMPLETED" | "ERROR"
const state = await wallet.getWithdrawalState(token, { starknetTxHash: tx.hash });

// Deposit state: "PENDING" | "COMPLETED" | "ERROR"
const depositState = await wallet.getDepositState(token, { externalTxHash: ethTxHash });

const result = await wallet.monitorWithdrawal(token, tx.hash);
// result.status: BridgeTransferStatus
// For CCTP when READY_TO_CLAIM: result.attestation, result.message, result.nonce

// You can pass a previously-fetched result back to avoid redundant network calls
const state = await wallet.getWithdrawalState(token, result);

const result = await wallet.monitorDeposit(token, ethTxHash);
const depositState = await wallet.getDepositState(token, result);