Sending a Transaction

This guide walks you through the process of sending a transaction using WalletConnect, specifically for interactions with OP_NET smart contracts.

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Steps to Send a Transaction

1. Get Required Parameters

Before sending a transaction, ensure you have the following parameters:

• account: Wallet account for transaction signing.

import { useWallet } from "@btc-vision/walletconnect";

const { account } = useWallet();

2. Define the Contract Instance

Use the getContract method to define the contract you want to interact with. This step ensures you have a properly typed contract instance that can encode calldata for the desired function.

const contractAddress = "bcrt1qexampleaddress"; // Replace with a valid contract address

const contractInstance = getContract<IOP_20Contract>(
  contractAddress, // Contract address
  OP_20_ABI, // Contract ABI
  provider: account.provider, // Provider instance
  network: account.network, // Target network
  address: account.address // Sender's address
);

Contract Interaction

Ensure the contract instance matches the contract you want to interact with, including the correct address and ABI.

Learn more about Interacting with Smart Contracts.

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3. Simulate the Transaction

Before sending the transaction, simulate it to ensure it will succeed. This step is crucial for avoiding failed transactions due to incorrect parameters.

const resApprove = await contractInstance.approve(account.address, 100n);
if (!resApprove) throw new Error("Approve call failed.");

4. Signing and Sending the Transaction

Use the sendTransaction method to sign and send the transaction.

const tx = await resApprove.sendTransaction({
  signer: account.signer!, // OP_WALLET doesn't need a signer
  maximumAllowedSatToSpend: 100_000n,
  network: account.network,
  refundTo: account.addressTyped,
});
if (!tx.transactionId) throw new Error("Failed to send transaction");

console.log("Transaction:", tx);

Full Example

import {
  IInteractionParameters,
  TransactionFactory,
} from "@btc-vision/transaction";
import { SupportedWallets, useWallet } from "@btc-vision/walletconnect";
import { getContract, IOP_20Contract, OP_20_ABI } from "opnet";

function BuildAnApproveTransaction() {
  const { account, connect, disconnect } = useWallet();

  async function approveRandomToken() {
    if (!account) throw new Error("Connect wallet first");

    const contractAddress = "bcrt1qexampleaddress"; // Replace with a valid contract address

    const contractInstance = getContract<IOP_20Contract>(
      contractAddress, // Contract address
      OP_20_ABI, // Contract ABI
      provider: account.provider, // Provider instance
      network: account.network, // Target network
      address: account.address // Sender's address
    );

    const resApprove = await contractInstance.approve(account.address, 100n);
    if (!resApprove)
      throw new Error("Approve call failed.");

    const tx = await resApprove.sendTransaction({
      signer: account.signer!, // OP_WALLET doesn't need a signer
      maximumAllowedSatToSpend: 100_000n,
      network: account.network,
      refundTo: account.addressTyped,
    });
    if (!tx.transactionId) throw new Error("Failed to send transaction");

    console.log("Transaction:", tx);
  }

  return (
    <div>
      {account ? (
        <div>
          <p>Connected Address: {account.addressTyped}</p>
          <button onClick={approveRandomToken}>Approve a random token</button>
          <button onClick={disconnect}>Disconnect</button>
        </div>
      ) : (
        <button onClick={() => connect(SupportedWallets.OP_WALLET)}>
          Connect Wallet
        </button>
      )}
    </div>
  );
}

export default BuildAnApproveTransaction;

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Best Practices

• Always simulate the transaction before sending it to ensure it will succeed.
• Use the maximumAllowedSatToSpend parameter to limit the amount of satoshis that can be spent in the transaction.
• Monitor the transaction status after sending it to confirm its success or failure.
• Handle errors gracefully to provide a better user experience.
• Ensure you have the correct contract address and ABI to avoid transaction failures.