Workshop: Getting to grips with the Arbitrum SDK, 23/04/2024

Hey there, fine people. So you wanna learn how to do L1 --> L2 messaging?

Well, you came to the right place.

Let's get started with:

git clone https://github.com/sashaaldrick/greeter-arb.git

cd greeter-arb

Make sure to copy the .env.sample to .env and populate the values as required. You'll need a L1 RPC URL for Sepolia, an L2 RPC URL for Arbitrum Sepolia and a private key for the wallet you'll be using. I recommend using Alchemy for the RPC URLs. Make sure this private key is funded on both Ethereum/Arbitrum Sepolia.

Then, depending on your JS runtime, you can run the following:

npm install or yarn install or bun install 🥖

After that, you can go ahead and run exec.js with:

npm run greeter or yarn run greeter or bun run greeter

You should get something like below if all went well:

$ hardhat run scripts/exec.js
WARNING: You are currently using Node.js v21.6.1, which is not supported by Hardhat. This can lead to unexpected behavior. See https://hardhat.org/nodejs-versions


Environmental variables properly set 👍
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Arbitrum Demo: Cross-chain Greeter
Lets
Go ➡️
...🚀

Deploying L1 Greeter 👋
deployed to 0x0c4FCc81Cc2D4FA82dE6A59819b35a0829aF292A
Deploying L2 Greeter 👋👋
deployed to 0x8A0759D6A635632ade77B198e28dbF9ef213389c
Counterpart contract addresses set in both greeters 👍
Current L2 greeting: "Hello world in L2"
Updating greeting from L1 to L2:
Current retryable base submission price is: 2321414320000
L2 gas price: 170220000
Sending greeting to L2 with 36004966780000 callValue for L2 fees:
Greeting txn confirmed on L1! 🙌 0xe17e0d96c37c08462d5531b67c0fe2029bb90bd4e9410dbd58501b2ab16b9c60
Waiting for the L2 execution of the transaction. This may take up to 10-15 minutes ⏰
L2 retryable ticket is executed 🥳 0x552edb44db69d3bdad0e9f13ba0ac9c93adc1e62556c5842a535ac6e7e6e2ac3
Updated L2 greeting: "Greeting from far, far away" 🥳