# Transactions

This document explains how to influence the blockchain's state by broadcasting transactions.

Transactions include:

  • a list of messages
  • an optional memo
  • a fee
  • a signature from a key

The messages included in a transaction contain the information that will be routed to a proper message handler in the node, which in turn parses the inputs and determines the next state of the blockchain.

# Create transactions

# Create a wallet

You will first want to create a wallet which you can use to sign transactions.

import { MnemonicKey, LCDClient } from '@terra-money/terra.js';

const mk = new MnemonicKey();
const terra = new LCDClient({
  URL: 'https://bombay-lcd.terra.dev',
  chainId: 'bombay-12'
});
const wallet = terra.wallet(mk);

# Create messages

import { MsgSend } from '@terra-money/terra.js';

const send = new MsgSend(
  wallet.key.accAddress,
  "<random-terra-address>",
  { uluna: 1000 }
);

# Create and Sign Transaction

const tx = await wallet.createAndSignTx({
  msgs: [send],
  memo: "Hello"
});

# Broadcast transaction

const txResult = await terra.tx.broadcast(tx);

The default broadcast mode is block, which waits until the transaction has been included in a block. This will give you the most information about the transaction, including events and errors while processing.

You can also use sync or async broadcast modes.

// const syncTxResult = await terra.tx.broadcastSync(tx);
// const asyncTxResult = await terra.tx.broadcastAsync(tx);

# Check events

If you broadcasted the transaction with block, you can get the events emitted by your transaction.

import { isTxError } from "@terra-money/terra.js";

const txResult = terra.tx.broadcast(tx);

if (isTxError(txResult)) {
  throw new Error(`encountered an error while running the transaction: ${txResult.code} ${txResult.codespace}`);
}

// check for events from the first message
txResult.logs[0].eventsByType.store_code;