Hedera Tx Builder

npm install @hashgraph/sdk

import { Client, AccountBalanceQuery, Hbar } from '@hashgraph/sdk';

const client = Client.forMainnet();
// Or for testnet:
const client = Client.forTestnet();

import { TransferTransaction, Hbar } from '@hashgraph/sdk';

const tx = new TransferTransaction()
  .addHbarTransfer(fromAccountId, new Hbar(-100)) // send
  .addHbarTransfer(toAccountId, new Hbar(100))    // receive
  .setTransactionMemo("Payment for goods");

// Sign with hashpack or operator
const signTx = await tx.sign(operatorKey);
const result = await signTx.execute(client);

new AccountCreateTransaction()
  .setKey(publicKey)
  .setInitialBalance(new Hbar(10))
  .setAccountMemo("My account");

new TokenAssociateTransaction()
  .setAccountId(accountId)
  .setTokenIds([tokenId1, tokenId2]);

new TopicMessageTransaction()
  .setTopicId(topicId)
  .setMessage("Hello Hedera!");