Genesis Block

Learn about the Genesis Block.

Background

Each blockchain has some genesis state when it's created. The Ethereum mainnet genesis block contained the addresses and balances of participants in the Ethereum pre-sale, marking the distribution of ether at the start of the network.

For the Avalanche L1-EVM and the Precompile-EVM, the genesis includes many more parameters that allow us to configure the behavior of our customized EVM and meet unique requirements. Since each blockchain has its own genesis block, we can create two blockchains of the same VM with different genesis blocks.

Format

Below, you can see an example of a genesis block:

{
  "config": {
    "chainId": 43214,
    "homesteadBlock": 0,
    "eip150Block": 0,
    "eip150Hash": "0x2086799aeebeae135c246c65021c82b4e15a2c451340993aacfd2751886514f0",
    "eip155Block": 0,
    "eip158Block": 0,
    "byzantiumBlock": 0,
    "constantinopleBlock": 0,
    "petersburgBlock": 0,
    "istanbulBlock": 0,
    "muirGlacierBlock": 0,
    "subnetEVMTimestamp": 0,
    "feeConfig": {
      "gasLimit": 15000000,
      "minBaseFee": 25000000000,
      "targetGas": 15000000,
      "baseFeeChangeDenominator": 36,
      "minBlockGasCost": 0,
      "maxBlockGasCost": 1000000,
      "targetBlockRate": 2,
      "blockGasCostStep": 200000
    },
    "allowFeeRecipients": false, 
    "txAllowListConfig": {
      "blockTimestamp": 0,
      "adminAddresses": [
        "0x8db97C7cEcE249c2b98bDC0226Cc4C2A57BF52FC"
      ]
    }
  },
  "alloc": {
    "8db97C7cEcE249c2b98bDC0226Cc4C2A57BF52FC": {
      "balance": "0x295BE96E64066972000000"
    }
  },
  "nonce": "0x0",
  "timestamp": "0x0",
  "extraData": "0x00",
  "gasLimit": "0xe4e1c0",
  "difficulty": "0x0",
  "mixHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
  "coinbase": "0x0000000000000000000000000000000000000000",
  "number": "0x0",
  "gasUsed": "0x0",
  "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000"
}

We will go through the relevant configurable parameters in the following activities. Some parameters are ignored here (eip150Block, byzantiumBlock, ...) because they are not relevant for most use cases.

VM Configuration

Create Your Genesis File

Genesis Block

Background

Format

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