# 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

You will first want to create a wallet which you can use to sign transactions. If you don't have a wallet yet, head to the wallet instructions instructions to set one up.

# Create messages

import { MsgSend } from "@paloma/Paloma.js";

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

# Create and Sign Transaction

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

# Broadcast transaction

const txResult = await Paloma.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 Paloma.tx.broadcastSync(tx);
// const asyncTxResult = await Paloma.tx.broadcastAsync(tx);

A wallet makes it easy to create a transaction by automatically fetching the account number and sequence from the blockchain. The fee parameter is optional -- if you don't include it, Paloma.js will automatically use your LCD's fee estimation settings to simulate the transaction within the node and include the resultant fee in your transaction.

const msgs = [ ... ]; // list of messages
const fee = Fee(...); // optional fee

const unsignedTx = await wallet.createTx({
  msgs,
  // fee, (optional)
  memo: 'this is optional'
});

You can then sign the transaction with the wallet's key, which will create a StdTx which you can later broadcast:

const tx = wallet.key.signTx(unsignedTx);

You can also use the convenience function Wallet.createAndSignTx(), which automatically generates a signed transaction to be broadcast:

const tx = await wallet.createAndSignTx({
  msgs,
  fee,
  memo: "this is optional",
});

# Check events

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

import { isTxError } from "@paloma/Paloma.js";

const txResult = Paloma.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;