Genesis Block
Genesis block configuration genesis is required in private networks.
| Syntax | Type | Description | Default |
|---|---|---|---|
| chainId | number | used in transaction signature to prevent transactions reply eip155 | |
| coinbase | string | benefeciary (ethereum address) of mining reward | address(0) |
| difficulty | string | difficulty (hexadecimal number) of the genesis block | 0x1 |
| mixHash | string | hash (hexadecimal) combined with nonce to prove effort spent to create block | 0x00..00 |
| gasLimit | string | total gas limit (hexadecimal number) for all transactions in a block | 0x47b760 |
| nonce | string | random hexadecimal number used in block computation | 0x0 |
| timestamp | string | genesis block creation date (hexadecimal) | 0x0 |
| accounts | Array | array of accounts to prefund and store code | |
| forks | object | supported forks and corresponding block number | |
| ethash | object | Proof of Work consensus configuration | |
| clique | object | Proof of Authority consensus configuration | |
| ibft2 | object | IBFT2 consensus configuration |
chainId#
chainId is the chain id value used in transaction signature to prevent transactions reply eip155
chainId is required.
chainId can't reuse existing public network chain id to avoid transaction replay.
| Network | Chain id |
|---|---|
| mainnet | 1 |
| ropsten | 3 |
| rinkeby | 4 |
| goerli | 5 |
| kotti | 6 |
| ethereum classic | 61 |
| Mordor | 63 |
| development | 2018 |
coinbase#
coinbase is the beneficiary (ethereum address) of mining reward.
coinbase is optional.
difficulty#
difficulty is the difficulty of the genesis block.
difficulty is optional.
mixHash#
mixHash is combined with the nonce to prove the effort spent to create a block.
mixHash is optional.
gasLimit#
gasLimit is the total gas limit for all transactions in a block.
gasLimit is optional.
nonce#
nonce is a random number used in block computation.
nonce is optional.
timestamp#
timestamp is block creation date.
timestamp is optional.
forks#
forks is an object, where the key is fork name and the value is the block number at which to activate this fork.
forks is optional.
if forks is missing, all forks will be activated at block 0 (genesis block) except DAO.
Later forks like muirglacier can't be activated before earlier forks like homestead. They must be ordered as in the following table:
note
Note that homestead fork will be ignored in PoA Clique consensus network by Parity (OpenEthereum) client.
| Syntax | Type | Description |
|---|---|---|
| homestead | number | Homestead fork activation block number |
| dao | number | DAO fork activation block number |
| eip150 | number | eip150 fork activation block number |
| eip155 | number | eip155 fork activation block number |
| eip158 | number | eip158 fork activation block number |
| byzantium | number | Byzantium fork activation block number |
| constantinople | number | Constantipole fork activation block number |
| petersburg | number | Petersburg fork activation block number |
| istanbul | number | Istanbul fork activation block number |
| muirglacier | number | Muir Glacier fork activation block number |
accounts#
accounts is an array of accounts to fund or store code.
accounts is optional.
accounts is recommended for networks where signers or validators are not rewarded with eth.
a single account has no defaults.
| Syntax | Type | Description |
|---|---|---|
| address | string | ethereum address |
| balance | string | account balance in hexadecimal |
| code | string | bytecode in hexadecimal |
| storage | map | key is the storage location in hexadecimal, and value in hexadecimal is the storage value |
ethash#
ethash is Proof of Work consensus engine configuration.
ethash is optional.
ethash can be set only in proof of work private networks.
ethash.fixedDifficulty has no default value.
| Syntax | Type | Description | Default |
|---|---|---|---|
| fixedDifficulty | number | fixed difficulty used in block computation |
clique#
clique is Proof of Authority clique consensus engine configuration.
clique is optional.
clique can be set only in proof of authority clique private networks.
At least one signer in clique.signers is required.
| Syntax | Type | Description | Default |
|---|---|---|---|
| blockPeriod | number | block time in seconds | 15 |
| epochLength | number | number of blocks after which to reset all votes | 1000 |
| signers | Array | array of ethereum addresses |
ibft2#
ibft2 is IBFT2 engine configuration.
ibft2 is optional.
ibft2 can be set only in IBFT2 private networks.
At least one validator in ibft2.validators is required.
| Syntax | Type | Description | Default |
|---|---|---|---|
| blockPeriod | number | block time in seconds | 15 |
| epochLength | number | number of blocks after which to reset all votes | 1000 |
| validators | array | array of ethereum addresses | |
| requestTimeout | number | timeout for each consensus round in seconds | 10 |
| messageQueueLimit | number | message queue limit | 1000 |
| duplicateMessageLimit | number | duplicate messages limit | 100 |
| futureMessagesLimit | number | future messages buffer limit | 1000 |
| futureMessagesMaxDistance | number | maximum height from current chain height for buffering future messages | 10 |