What this skill does

--- name: hedera-tx-builder description: Build and sign Hedera transactions. Use for: (1) Creating HBAR transfers, (2) Token operations, (3) Smart contract calls, (4) Submitting to Hedera network. --- # Hedera Transaction Builder ## Setup ```bash npm install @hashgraph/sdk ``` ## Client Setup ```typescript import { Client, AccountBalanceQuery, Hbar } from '@hashgraph/sdk'; const client = Client.forMainnet(); // Or for testnet: const client = Client.forTestnet(); ``` ## Transfer HBAR ```typescript 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); ``` ## Key Transaction Types ### AccountCreate ```typescript new AccountCreateTransaction() .setKey(publicKey) .setInitialBalance(new Hbar(10)) .setAccountMemo("My account"); ``` ### TokenAssociate ```typescript new TokenAssociateTransaction() .setAccountId(accountId) .setTokenIds([tokenId1, tokenId2]); ``` ### TopicMessage ```typescript new TopicMessageTransaction() .setTopicId(topicId) .setMessage("Hello Hedera!"); ``` ## Network Endpoints - **Mainnet**: `https://mainnet.hashio.io/api` - **Testnet**: `https://testnet.hashio.io/api` ## Important Concepts - **Hbar**: 1 HBAR = 100,000,000 tinybars - **Account ID**: Format `shard.realm.num` (e.g., `0.0.12345`) - **Transaction Fee**: Small HBAR fee for each transaction - **Transaction Valid Duration**: 180 seconds by default