Subnet Creation

A quick review of creating a Subnet on Avalanche - the foundation for our permissioned L1

In the Avalanche Fundamentals course, you learned how to quickly set up an L1 using the Developer Console. This section provides an in depth review of that flow, understanding what comes pre-configured in our genesis, and laying the foundation for what we will need for our Permissioned L1.

Creating a Subnet

Let's create a fresh new Subnet that we can use during this course to test all of the tools and flows for managing Permissioned L1s.

Connect & Fund Core Wallet

Download Core Wallet if not already installed
Connect your wallet and set to Tesnet mode (upper-right toggle button)
Use the faucet button in this wallet component (below your C-chain balance) to claim test AVAX on the C-Chain
Use the same button (but below P-Chain balance) to claim test AVAX on the P-Chain

Create Subnet and Blockchain Records

Create the Subnet by issuing two transactions on the P-Chain (hence the need for test AVAX on the P-chain).

These transactions are:

CreateSubnetTx - Creates a Subnet identified by the transaction hash
CreateChainTx - Adds a blockchain to the Subnet

For this guide, we will create our blockchain as an uncustomized EVM so you just need to rename it (if you want).

On Step 2: Create a Chain select the Genesis JSON tab to the right and skim through it. No need to understand it all but good to get familiar with it before the next section.

Create Chain

Create a subnet and add a new blockchain with custom parameters and genesis data.

Step 1: Create a Subnet

Every chain needs to be associated with a Subnet. If you don't have a Subnet, create one here. If you already have a Subnet, skip to the next step.

Subnet Owner

Step 2: Create a Chain

Enter the parameters for your new chain.

Subnet ID

Chain Name

Virtual Machine

Select what Virtual Machine (VM) your chain will use.

Uncustomized EVM

Customized EVM or alternative VM (Experts only)

Chain Parameters

Enter the basic parameters of your L1, such as the EVM chain ID.

EVM Chain ID

Unique identifier for your blockchain. Check chainlist.org to avoid conflicts.

View registered chain IDs on chainlist.org →

Permissions

By design, blockchain networks are fully permissionless, allowing anyone to transact and deploy smart contracts. However, certain use cases require permissioning to control who can participate in transactions or deploy contracts. On Avalanche, permissioning is an optional feature for Layer 1 blockchains that may or may not be activated, depending on the network's needs.

Tokenomics

Tokenomics in Layer 1 blockchains on the Avalanche network are highly flexible, allowing developers to tailor economic models to their specific needs. Each L1 can define its own native token, specifying its initial allocation, distribution mechanism, and whether it should be mintable for ongoing issuance. This enables a wide range of economic designs, from fixed-supply tokens to inflationary models that support network sustainability.

Transaction Fees & Gas

In addition to the native token, you can also configure the transaction fees (also known as gas fees). This allows Avalanche L1s to define the desired or maximal throughput of the blockchain differently.

Fill in the configuration to generate the genesis file.

Explore more

Avalanche Builder Tooling

Key Parameters:

Subnet Owner: P-chain address of your connected wallet
Chain Name: Your blockchain's name
VM ID: Default value srEX...Dy when creating with an uncustomized VM
Genesis Data: Initial blockchain configuration

Set Up Validator Node

Launch a node to track your Subnet using Docker. This node will become a validator for your Subnet, and later will be managed by the Validator Manager contract when we convert to L1.

Node Setup with Docker

This will start a Docker container running an RPC or validator node that tracks your L1.

Set up Instance

Set up a linux server with any cloud provider, like AWS, GCP, Azure, or Digital Ocean. Low specs (e.g. 2 vCPUs, 4GB RAM, 20GB storage) are sufficient for basic tests. For more extensive test and production L1s use a larger instance with appropriate resources (e.g. 8 vCPUs, 16GB RAM, 1 TB storage).

If you do not have access to a server, you can also run a node for educational purposes locally. Simply select the "RPC Node (Local)" option in the next step.

Docker Installation

Make sure you have Docker installed on your system. You can use the following commands to install it:

# Install Docker using convenience script
curl -fsSL https://get.docker.com -o get-docker.sh
sudo sh get-docker.sh
sudo usermod -aG docker $USER
newgrp docker
 
# Test installation
docker run -it --rm hello-world

If you do not want to use Docker, you can follow the instructions here.

Select L1

Enter the Avalanche Subnet ID of the L1 you want to run a node for.