Test and emulate

Emulator allows developers to test and validate their transactions in a controlled environment without interacting with a real blockchain. This is important for debugging, rapid prototyping, and ensuring transaction logic is correct before deploying to a testnet or mainnet

Initialize emulator

This setup allows you to create a mock blockchain state with predefined addresses and asset distributions

const emulator = new Emulator([
  {
    address: "addr_test...",
    assets: { lovelace: 3000000000n },
  },
  // You can add multiple addresses with different asset distributions
]);
 
const lucid = await Lucid(emulator);

Working with time ranges

const tx = await lucid
  .newTx()
  .validTo(emulator.now())
  .complete();

Distribute staking rewards

The emulator allows you to conveniently distribute rewards to all delegated stake addresses.

emulator.distributeRewards(100000000n);
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At any point in the emulation you can call the following code to get the current state of the emulated blockchain. It gives you insights into the distribution of funds across addresses and shows you the current block height and slot.

emulator.log();

Example - Simulated transaction

const tx = await lucid
  .newTx()
  .pay.ToAddress("addr_test...", { lovelace: 1000000n })
  .complete();
const signedTx = await tx.sign().complete();
const txHash = await signedTx.submit();
 
// Simulate the passage of time and block confirmations in the emulator
await emulator.awaitBlock(10);

Protocol Parameters

You can use the emulator with custom protocol parameters to bypass these limits during development.

const lucid = Lucid("<Provider>", "<Network>", {
  presetProtocolParameters: {
    ...PROTOCOL_PARAMETERS_DEFAULT,
    minFeeA: 0,           // per-byte fee
    minFeeB: 0,           // constant fee
    priceMem: 0,          
    priceStep: 0,        
    coinsPerUtxoByte: 0n, // min-ADA requirement
  },
});

This configuration disables fees and minimum ADA requirements, allowing you to test and debug your transaction logic without being constrained by network limits. Remember to test with actual protocol parameters before deploying to mainnet.

Transaction ChainingSmart Handles ⤴