Tracing deposits and withdrawals

In this tutorial, you'll learn how to use the viem (opens in a new tab) library to trace a Standard Bridge deposit or withdrawal between L1 and L2. You'll specifically learn how to determine the status of a deposit or withdrawal and how to retrieve the transaction receipt for the executed transaction on L1 (for withdrawals) or L2 (for deposits).

Dependencies

• node (opens in a new tab)
• pnpm (opens in a new tab)

Create a demo project

You're going to use the viem library for this tutorial. Since viem is a Node.js (opens in a new tab) library, you'll need to create a Node.js project to use it.

mkdir trace-trx
cd trace-trx

pnpm init

pnpm add viem 

Add RPC URLs to your environment

You'll be using the getTransactionReceipt function from the viem library during this tutorial. This function use event queries to retrieve the receipt for a deposit or withdrawal. Since this function uses large event queries, you'll need to use an RPC provider like Alchemy (opens in a new tab) that supports indexed event queries. Grab an L1 and L2 RPC URL for Sepolia and Metal L2 Testnet, respectively.

export L1_RPC_URL="https://YOUR_L1_ SEPOLIA_RPC_URL_HERE"
export L2_RPC_URL="https://YOUR_L2_OP_SEPOLIA_RPC_URL_HERE"

Start the Node REPL

You're going to use the Node REPL to interact with viem. To start the Node REPL, run the following command in your terminal:

node

This will bring up a Node REPL prompt that allows you to run JavaScript code.

Import dependencies

You need to import some dependencies into your Node REPL session.

Import viem

  const { createPublicClient, http } = require('viem');
  const { optimismSepolia, sepolia } = require('viem/chains');

Set session variables

You'll need a few variables throughout this tutorial. Let's set those up now.

const l1RpcUrl = process.env.L1_RPC_URL;
const l2RpcUrl = process.env.L2_RPC_URL;

const depositHash = '0x5896d6e4a47b465e0d925723bab838c62ef53468139a5e9ba501efd70f90cccb'

const withdrawalHash = '0x18b8b4022b8d9e380fd89417a2e897adadf31e4f41ca17442870bf89ad024f42'

const l1Client = createPublicClient({
  chain: sepolia,
  transport: http(l1RpcUrl),
});
 
const l2Client = createPublicClient({
  chain: optimismSepolia,
  transport: http(l2RpcUrl),
});

Trace a Deposit

You can use viem to trace a deposit.

console.log('Grabbing deposit status...')
const depositStatus = await l2Client.getTransactionReceipt({ hash: depositHash });
console.log(depositStatus);

console.log('Grabbing deposit receipt...')
const depositReceipt = await l2Client.getTransaction({ hash: depositHash });
console.log(depositReceipt);

console.log('Grabbing deposit txn...')
const depositTransaction = await l2Client.getTransaction({ hash: depositHash });
console.log(depositTransaction);

Trace a withdrawal

You can use viem's functions to trace a withdrawal.

console.log('Grabbing withdrawal status...')
const withdrawalStatus = await l1Client.getTransactionReceipt({ hash: withdrawalHash });
console.log(withdrawalStatus);

console.log('Grabbing withdrawal receipt...')
const withdrawalReceipt = await l1Client.getTransaction({ hash: withdrawalHash });
console.log(withdrawalReceipt);

console.log('Grabbing withdrawal txn...')
const withdrawalTransaction = await l1Client.getTransaction({ hash: withdrawalHash });
console.log(withdrawalTransaction);

Next steps

• Check out the tutorial on bridging ERC-20 tokens with the Optimism SDK to learn how to create deposits and withdrawals.
• You can also check out the tutorial on viewing deposits and withdrawals by address to find deposits and withdrawals to trace.