First Transaction

A couple fundamentals to remember are that in Cardano’s eUTxO model, a transaction can consume one or more UTxOs as inputs. Create one or more UTxOs as outputs and that a transaction must be balanced (sum of inputs = sum of outputs + fees).

Steps to Construct a Transaction

Build

Let’s create a simple transaction where we send 5 ADA to two recipients each:


const tx = await lucid
  .newTx()
  .pay.ToAddress("addr_test1...", { lovelace: 5_000_000n })
  .pay.ToAddress("addr_test2...", { lovelace: 5_000_000n })
  .complete();

Sign


const signedTx = await tx.sign.withWallet().complete();

Submit


const txHash = await signedTx.submit();

⚠️

Remember to select a wallet before attempting to build and submit transactions.

Putting it all Together


import { Lucid, Koios, generateSeedPhrase } from "@evolution-sdk/lucid";
 
async function firstTransaction() {
  // Initialize Lucid with a provider
  const lucid = await Lucid(
    new Koios("https://preprod.koios.rest/api/v1"),
    "Preprod"
  );
 
  const seedPhrase = generateSeedPhrase(); // BIP-39
  lucid.selectWallet.fromSeed(seedPhrase); // Select a wallet for signing
 
  // Build, sign and submit transaction
  const tx = await lucid
    .newTx()
    .pay.ToAddress("addr_test1...", { lovelace: 5_000_000n }) // Pay 5 ADA to addr_test1...
    .pay.ToAddress("addr_test2...", { lovelace: 5_000_000n }) // Pay 5 ADA to addr_test2...
    .complete(); // Balance the transaction and initiate UTxO selection
 
  const signedTx = await tx.sign.withWallet().complete();
  const txHash = await signedTx.submit();
 
  console.log("Transaction Submitted:", txHash);
}