Getting Started with Golem Base First Testnet (L2+L3)

This guide is intended for Web3 developers and enthusiasts.

Follow these simple steps to start using Golem Base L2 "Erech" and L3 "Kaolin" testnets.

During this tutorial you will:

• Bridge test ETH from Holesky to Golem Base L2 “Erech”
• Run sample transaction on Golem Base L2
• Bridge test ETH from Golem Base L2 “Erech” to Golem Base L3 “Kaolin”
• Interact with data on Golem Base L3 either by writing your own code or through simple PoC built to demonstrate L3 capabilities - dPaste.

Disclaimer: This guide is provided for informational and educational purposes only. Golem Base is an experimental, pre-production testnet platform intended for developers and technically proficient users. Terms and conditions apply: glm.zone/base-toc

Step 0: Organize a Wallet for Ethereum Testnet

We recommend starting with MetaMask as your browser-based wallet. You can install it here; simply click the Get Metamask link and follow the steps for getting started by agreeing to the terms and then clicking Create a new wallet. (However, you can use any other browser-based wallet as well.)

Step 1: Get Test ETH on Holesky

First, configure your Wallet to use Holesky Testnet.

1. Open the MetaMask extension
2. Click the Ethereum Mainnet icon; a box should pop up listing networks. Scroll to the bottom of this box and click Add a custom network.
3. In the Add a custom network box, fill it in with the following: Network name: Holesky Default RPC URL: https://ethereum-holesky.publicnode.com Chain ID: 17000 Currency symbol: ETH Block explorer URL: https://holesky.etherscan.io/

Grab some test ETH from any public Holesky faucet. (i.e. Google, Holesky proof of work) You'll bridge those test tokens to Golem Base Testnet “Erech” in the next step.

Step 2: Bridge Your ETH to Golem Base L2 “Erech”

Transfer your test ETH to Golem Base bridge smart contract to move test ETH from Holesky to Golem Base L2:

1. In your wallet, select the Holesky network and click Send.
2. Copy the following into the To box: 0x54D6C1435ac7B90a5d46d01EE2f22Ed6fF270ED3 (This is a direct bridge contract address).
3. Click Continue.
4. A Transaction Request box will open. Click Confirm.

This transaction bridges your test ETH from Holesky to Golem Base L2 testnet "Erech" automatically. The bridging process typically takes just a few minutes

Step 3: Add Golem Base Testnet “Erech” to MetaMask / Wallet

1. Follow the same steps as earlier for adding a network and use the following: Network name: Golem Base L2 Testnet-001 "Erech" Default RPC URL: https://execution.holesky.l2.gobas.me Chain ID: 393530 Currency symbol: ETH Block explorer URL: https://explorer.golem-base.io
2. Click Save. You should see a message at the bottom of the screen that the network was successfully added.

You can now switch between networks by clicking the network name in the upper-left corner and choosing one from the box that opens.

Step 4: Test Your L2 Setup

Let's verify everything is working:

• Switch your wallet's network to Golem Base L2 Testnet-001 "Erech".

  • Tip: You should see the amount you sent in the previous step.

• Optionally, you can test that the L2 Testnet setup is correct by sending a small amount of test ETH (like 0.001) to your own address.

  Visit Golem Base block explorer at explorer.golem-base.io and look up your wallet address. You should see your transaction in the list, confirming you've successfully completed your first interaction with Golem Base!

Step 5: Bridge from L2 to L3 "Kaolin"

Now let's move some test ETH from L2 "Erech" to L3 "Kaolin":

• While still on the "Erech" network, send the desired amount of your L2 test ETH to L3 bridge: 0x5c857718caea1f6e9b0a7adf1415d0b98b6498d0

• This will bridge your test ETH from L2 to Golem Base L3 testnet "Kaolin"

• You can track your bridge transactions using bridging monitoring tool:

• Visit https://bridgette.kaolin.holesky.golem-base.io/ to check if your L2→L3 bridge transaction is still pending or has been finalized. You’ll see a list of recent transactions associated with your wallet address.

Step 6: Add Golem Base L3 Testnet to MetaMask / Wallet

Set up Golem Base L3 in your MetaMask / Wallet by adding a new network with these details:

• Network Name: Golem Base L3 Testnet "Kaolin"
• RPC URL: https://rpc.kaolin.holesky.golem-base.io/
• Chain ID: 600606
• Currency Symbol: ETH

Step 7: Verify Your L3 Setup

Let's check that your L3 setup is working:

• Switch your wallet's network to "Golem Base L3 Testnet Kaolin"
• After the bridging process is successful (typically less than a minute), you should see the test ETH in your wallet on L3

Step 8: Explore the Golem Base Ecosystem

Congratulations! You've now successfully:

• Bridged test ETH from Ethereum Holesky testnet to Golem Base L2 "Erech"
• Bridged from Golem Base L2 testnet "Erech" to Golem Base L3 testnet "Kaolin"
• Now you can experiment with Golem Base L3 testnet either by:
  • Checking out dPaste - simple application built on top of Golem Base that allows you to save and share notes.
  • Create your own app - by using Golem Base SDK. More tutorials for builders will be provided in coming weeks.