HotBridge

A fast and cheap bridge protocol over HOT Protocol that uses the NEAR Intents engine for exchange. Available for EVM (10+ chains), NEAR, Solana, TON, Stellar

yarn add @hot-labs/omni-sdk

Demo UI

Deploy: https://hot-dao.github.io/omni-sdk

Covered cases:

• Connect NEAR, EVM (currently deposit only to Intent account binded to NEAR wallet)
• Deposit token widget (from NEAR, EVM)
• Withdraw token widget (to NEAR, EVM)
• Find pending withdrawals and finish them
• View HOT Bridge tokens balances on Intents

Setup HotBridge

const omni = new OmniBridge({
  logger: console, // optional

  tonRpc: env.TON_API_KEY, // only if use TON
  evmRpc: { 56: ["rpc"] }, // only if use EVM
  solanaRpc: ["rpc"], // only if use SOLANA

  // Relayer for execute intents and omni bridge operations
  executeNearTransaction: async ({ receiverId, actions }) => {
    const hash = await relayer.signAndSendTransaction({ receiverId, actions }).
    return { sender: relayer.accountId, hash };
  },
});

Deposit to HotBridge

const intentAccount = "account";
const hash = await omni.ton.deposit({
  token: "native",
  amount: 100000000n,
  sendTransaction: async (tx) => "hash", // execute by payer
  sender: "address", // payer account
  intentAccount, // intent account to deposit
});

// usually from 30 seconds to 2 minutes, but can wait indefinitely
const abortController = new AbortController(); // optional argument
const pending = await omni.waitPendingDeposit(Network.Ton, hash, intentAccount, abortController.signal);
await omni.finishDeposit(pending);

Withdraw from HotBridge

// Only intent signer need for withdraw
const { nonce } = await omni.withdrawToken({
  signIntents: async (intents) => signedIntent, // sign by intent account with omni balance
  intentAccount: "account",
  chain: Network.Base,
  receiver: "0x...", // any onchain receiver
  token, // onchain address of token to withdraw
  gasless: true,
  amount: 10n,
  ...signer,
});

// gasless withdraw
if (nonce == null) return;

const withdraw = await omni.getPendingWithdraw(nonce);
await omni.evm.withdraw({
  sendTransaction: async () => "hash", // any tx executor for claim tokens for receiver
  sender: "address", // any tx executor address
  ...withdraw,
});

Finish pending withdraw

// Get all uncompleted withdrawals for this bnb address
const pendings = await omni.getPendingWithdrawalsWithStatus(56, "0xAddress");

// Clear completed withdrawals
const completed = pendings.filter((t) => t.completed);
if (completed.length) await omni.clearPendingWithdrawals(completed);

// Finish all
const uncompleted = pendings.filter((t) => !t.completed);
for (const pending of uncompleted) {
  await omni.evm.withdraw({ ...pending, ...signer }); // push tx
}

Processing pending withdrawals on the fly

const execute = async (pending: WithdrawArgsWithPending): Promise<string | null> => {
  try {
    // If the pending withdrawal is less than 5 minutes old, do not try to withdraw again
    if (Date.now() / 1000 - pending.timestamp < 5 * 60) return null;

    // Trying to withdraw TON
    if (pending.chain === Network.Ton || pending.chain === Network.OmniTon) {
      return await bridge.ton.withdraw({ sendTransaction, refundAddress: "address", ...pending });
    }

    // Trying to withdraw Stellar
    if (pending.chain === Network.Stellar) {
      return await bridge.stellar.withdraw({ sender: "address", sendTransaction, ...pending });
    }

    // Trying to withdraw Solana
    if (pending.chain === Network.Solana) {
      const solana = await bridge.solana();
      return await solana.withdraw({ sender: "address", sendTransaction, ...pending });
    }

    return await bridge.evm.withdraw({ sendTransaction, ...pending });
  } catch (error) {
    console.error(error);
    return null;
  }
};

const abortController = new AbortController();
bridge.iterateWithdrawals({ signal: abortController.signal, execute });