C-Chain Configs

Note: These are the configuration options available in the coreth codebase. To set these values, you need to create a configuration file at {chain-config-dir}/C/config.json. This file does not exist by default.

For example if chain-config-dir has the default value which is $HOME/.avalanchego/configs/chains, then config.json should be placed at $HOME/.avalanchego/configs/chains/C/config.json.

For the AvalancheGo node configuration options, see the AvalancheGo Configuration page.

This document describes all configuration options available for coreth.

The C-Chain config is printed out in the log when a node starts. Default values for each config flag are specified below.

Default values are overridden only if specified in the given config file. It is recommended to only provide values which are different from the default, as that makes the config more resilient to future default changes. Otherwise, if defaults change, your node will remain with the old values, which might adversely affect your node operation.

Example Configuration

{
  "eth-apis": ["eth", "eth-filter", "net", "web3"],
  "pruning-enabled": true,
  "commit-interval": 4096,
  "trie-clean-cache": 512,
  "trie-dirty-cache": 512,
  "snapshot-cache": 256,
  "rpc-gas-cap": 50000000,
  "log-level": "info",
  "metrics-expensive-enabled": true,
  "continuous-profiler-dir": "./profiles",
  "state-sync-enabled": false,
  "accepted-cache-size": 32
}

Configuration Format

Configuration is provided as a JSON object. All fields are optional unless otherwise specified.

API Configuration

Ethereum APIs

Option	Type	Description	Default
`eth-apis`	array of strings	List of Ethereum services that should be enabled	`["eth", "eth-filter", "net", "web3", "internal-eth", "internal-blockchain", "internal-transaction"]`
`eth`	bool	Adds the `eth_coinbase` and `eth_etherbase` RPC calls to the `eth_*` namespace.	`true`
`eth-filter`	bool	Enables the public filter API for the `eth_*` namespace and adds the following RPC calls (see here for complete documentation): - `eth_newPendingTransactionFilter` - `eth_newPendingTransactions` - `eth_newAcceptedTransactions` - `eth_newBlockFilter` - `eth_newHeads` - `eth_logs` - `eth_newFilter` - `eth_getLogs` - `eth_uninstallFilter` - `eth_getFilterLogs` - `eth_getFilterChanges`	`true`
`admin`	bool	Adds the `admin_importChain` and `admin_exportChain` RPC calls to the `admin_*` namespace	`false`
`debug`	bool	Adds the following RPC calls to the `debug_*` namespace. - `debug_dumpBlock` - `debug_accountRange` - `debug_preimage` - `debug_getBadBlocks` - `debug_storageRangeAt` - `debug_getModifiedAccountsByNumber` - `debug_getModifiedAccountsByHash` - `debug_getAccessibleState` The following RPC calls are disabled for any nodes with `state-scheme = firewood`: - `debug_storageRangeAt` - `debug_getModifiedAccountsByNumber` - `debug_getModifiedAccountsByHash`	`false`.
`net`	bool	Adds the following RPC calls to the `net_*` namespace. - `net_listening` - `net_peerCount` - `net_version` Note: Coreth is a virtual machine and does not have direct access to the networking layer, so `net_listening` always returns true and `net_peerCount` always returns 0. For accurate metrics on the network layer, users should use the AvalancheGo APIs.	`true`
`debug-tracer`	bool	Adds the following RPC calls to the `debug_*` namespace. - `debug_traceChain` - `debug_traceBlockByNumber` - `debug_traceBlockByHash` - `debug_traceBlock` - `debug_traceBadBlock` - `debug_intermediateRoots` - `debug_traceTransaction` - `debug_traceCall`	`false`
`web3`	bool	Adds the `web3_clientVersion` and `web3_sha3` RPC calls to the `web3_*` namespace	`true`
`internal-eth`	bool	Adds the following RPC calls to the `eth_*` namespace. - `eth_gasPrice` - `eth_baseFee` - `eth_maxPriorityFeePerGas` - `eth_feeHistory`	`true`
`internal-blockchain`	bool	Adds the following RPC calls to the `eth_*` namespace. - `eth_chainId` - `eth_blockNumber` - `eth_getBalance` - `eth_getProof` - `eth_getHeaderByNumber` - `eth_getHeaderByHash` - `eth_getBlockByNumber` - `eth_getBlockByHash` - `eth_getUncleBlockByNumberAndIndex` - `eth_getUncleBlockByBlockHashAndIndex` - `eth_getUncleCountByBlockNumber` - `eth_getUncleCountByBlockHash` - `eth_getCode` - `eth_getStorageAt` - `eth_call` - `eth_estimateGas` - `eth_createAccessList` `eth_getProof` is disabled for any node with `state-scheme = firewood`	`true`
`internal-transaction`	bool	Adds the following RPC calls to the `eth_*` namespace. - `eth_getBlockTransactionCountByNumber` - `eth_getBlockTransactionCountByHash` - `eth_getTransactionByBlockNumberAndIndex` - `eth_getTransactionByBlockHashAndIndex` - `eth_getRawTransactionByBlockNumberAndIndex` - `eth_getRawTransactionByBlockHashAndIndex` - `eth_getTransactionCount` - `eth_getTransactionByHash` - `eth_getRawTransactionByHash` - `eth_getTransactionReceipt` - `eth_sendTransaction` - `eth_fillTransaction` - `eth_sendRawTransaction` - `eth_sign` - `eth_signTransaction` - `eth_pendingTransactions` - `eth_resend`	`true`
`internal-tx-pool`	bool	Adds the following RPC calls to the `txpool_*` namespace. - `txpool_content` - `txpool_contentFrom` - `txpool_status` - `txpool_inspect`	`false`
`internal-debug`	bool	Adds the following RPC calls to the `debug_*` namespace. - `debug_getHeaderRlp` - `debug_getBlockRlp` - `debug_printBlock` - `debug_chaindbProperty` - `debug_chaindbCompact`	`false`
`debug-handler`	bool	Adds the following RPC calls to the `debug_*` namespace. - `debug_verbosity` - `debug_vmodule` - `debug_backtraceAt` - `debug_memStats` - `debug_gcStats` - `debug_blockProfile` - `debug_setBlockProfileRate` - `debug_writeBlockProfile` - `debug_mutexProfile` - `debug_setMutexProfileFraction` - `debug_writeMutexProfile` - `debug_writeMemProfile` - `debug_stacks` - `debug_freeOSMemory` - `debug_setGCPercent`	`false`
`internal-account`	bool	Adds the `eth_accounts` RPC call to the `eth_*` namespace	`true`
`internal-personal`	bool	Adds the following RPC calls to the `personal_*` namespace. - `personal_listAccounts` - `personal_listWallets` - `personal_openWallet` - `personal_deriveAccount` - `personal_newAccount` - `personal_importRawKey` - `personal_unlockAccount` - `personal_lockAccount` - `personal_sendTransaction` - `personal_signTransaction` - `personal_sign` - `personal_ecRecover` - `personal_signAndSendTransaction` - `personal_initializeWallet` - `personal_unpair`	`false`

Enabling Avalanche Specific APIs

Option	Type	Description	Default
`admin-api-enabled`	bool	Enables the Admin API	`false`
`admin-api-dir`	string	Specifies the directory for the Admin API to use to store CPU/Mem/Lock Profiles	`""`
`warp-api-enabled`	bool	Enable the Warp API for cross-chain messaging	`false`

API Limits and Security

Option	Type	Description	Default
`rpc-gas-cap`	uint64	Maximum gas limit for RPC calls	`50,000,000`
`rpc-tx-fee-cap`	float64	Maximum transaction fee cap in AVAX	`100`
`api-max-duration`	duration	Maximum duration for API calls (0 = no limit)	`0`
`api-max-blocks-per-request`	int64	Maximum number of blocks per getLogs request (0 = no limit)	`0`
`http-body-limit`	uint64	Maximum size of HTTP request bodies (0 = no limit)	`0`
`batch-request-limit`	uint64	Maximum number of requests that can be batched in an RPC call. For no limit, set either this or `batch-response-max-size` to 0	`1000`
`batch-response-max-size`	uint64	Maximum size (in bytes) of response that can be returned from a batched RPC call. For no limit, set either this or `batch-request-limit` to 0. Defaults to `25 MB`	`1000`

WebSocket Settings

Option	Type	Description	Default
`ws-cpu-refill-rate`	duration	Rate at which WebSocket CPU usage quota is refilled (0 = no limit)	`0`
`ws-cpu-max-stored`	duration	Maximum stored WebSocket CPU usage quota (0 = no limit)	`0`

Cache Configuration

Trie Caches

Option	Type	Description	Default
`trie-clean-cache`	int	Size of the trie clean cache in MB	`512`
`trie-dirty-cache`	int	Size of the trie dirty cache in MB	`512`
`trie-dirty-commit-target`	int	Memory limit to target in the dirty cache before performing a commit in MB	`20`
`trie-prefetcher-parallelism`	int	Maximum concurrent disk reads trie prefetcher should perform	`16`

Other Caches

Option	Type	Description	Default
`snapshot-cache`	int	Size of the snapshot disk layer clean cache in MB	`256`
`accepted-cache-size`	int	Depth to keep in the accepted headers and logs cache (blocks)	`32`
`state-sync-server-trie-cache`	int	Trie cache size for state sync server in MB	`64`

Ethereum Settings

Transaction Processing

⚠️ WARNING: allow-unfinalized-queries should likely be set to false in production. Enabling this flag can result in a confusing/unreliable user experience. Enabling this flag should only be done when users are expected to have knowledge of how Snow* consensus finalizes blocks. Unlike chains with reorgs and forks that require block confirmations, Avalanche does not increase the confidence that a block will be finalized based on the depth of the chain. Waiting for additional blocks does not confirm finalization. Enabling this flag removes the guarantee that the node only exposes finalized blocks; requiring users to guess if a block is finalized.

Option	Type	Description	Default
`preimages-enabled`	bool	Enable preimage recording	`false`
`allow-unfinalized-queries`	bool	Allow queries for unfinalized blocks	`false`
`allow-unprotected-txs`	bool	Allow unprotected transactions (without EIP-155)	`false`
`allow-unprotected-tx-hashes`	[]TxHash	Specifies an array of transaction hashes that should be allowed to bypass replay protection. This flag is intended for node operators that want to explicitly allow specific transactions to be issued through their API.	an empty list
`local-txs-enabled`	bool	Enable treatment of transactions from local accounts as local	`false`

Snapshots

Option	Type	Description	Default
`snapshot-wait`	bool	Wait for snapshot generation on startup	`false`
`snapshot-verification-enabled`	bool	Enable snapshot verification	`false`

Pruning and State Management

Note: If a node is ever run with pruning-enabled as false (archival mode), setting pruning-enabled to true will result in a warning and the node will shut down. This is to protect against unintentional misconfigurations of an archival node. To override this and switch to pruning mode, in addition to pruning-enabled: true, allow-missing-tries should be set to true as well.

Basic Pruning

Option	Type	Description	Default
`pruning-enabled`	bool	Enable state pruning to save disk space	`true`
`commit-interval`	uint64	Interval at which to persist EVM and atomic tries (blocks)	`4096`
`accepted-queue-limit`	int	Maximum blocks to queue before blocking during acceptance	`64`

State Reconstruction

Option	Type	Description	Default
`allow-missing-tries`	bool	Suppress warnings about incomplete trie index	`false`
`populate-missing-tries`	uint64	Starting block for re-populating missing tries (null = disabled)	`null`
`populate-missing-tries-parallelism`	int	Concurrent readers for re-populating missing tries	`1024`

Offline Pruning

Note: If offline pruning is enabled it will run on startup and block until it completes (approximately one hour on Mainnet). This will reduce the size of the database by deleting old trie nodes. While performing offline pruning, your node will not be able to process blocks and will be considered offline. While ongoing, the pruning process consumes a small amount of additional disk space (for deletion markers and the bloom filter). For more information see here.. Since offline pruning deletes old state data, this should not be run on nodes that need to support archival API requests. This is meant to be run manually, so after running with this flag once, it must be toggled back to false before running the node again. Therefore, you should run with this flag set to true and then set it to false on the subsequent run.

Option	Type	Description	Default
`offline-pruning-enabled`	bool	Enable offline pruning	`false`
`offline-pruning-bloom-filter-size`	uint64	Bloom filter size for offline pruning in MB	`512`
`offline-pruning-data-directory`	string	Directory for offline pruning data	-

Historical Data

Option	Type	Description	Default
`historical-proof-query-window`	uint64	Number of blocks before last accepted for proof queries (archive mode only, ~24 hours)	`43200`
`state-history`	uint64	Number of most recent states that are accesible on disk (pruning mode only)	`32`

Transaction Pool Configuration

Option	Type	Description	Default
`tx-pool-price-limit`	uint64	Minimum gas price for transaction acceptance	`1`
`tx-pool-price-bump`	uint64	Minimum price bump percentage for transaction replacement	`10%`
`tx-pool-account-slots`	uint64	Maximum number of executable transaction slots per account	`16`
`tx-pool-global-slots`	uint64	Maximum number of executable transaction slots for all accounts	`5120`
`tx-pool-account-queue`	uint64	Maximum number of non-executable transaction slots per account	`64`
`tx-pool-global-queue`	uint64	Maximum number of non-executable transaction slots for all accounts	`1024`
`tx-pool-lifetime`	duration	Maximum duration in nanoseconds a non-executable transaction will be allowed in the poll	`600000000000` (10 minutes)
`price-options-slow-fee-percentage`	integer	Percentage to apply for slow fee estimation	`95`
`price-options-fast-fee-percentage`	integer	Percentage to apply for fast fee estimation	`105`
`price-options-max-tip`	integer	Maximum tip in wei for fee estimation	`20000000000` (20 Gwei)

Push Gossip Settings

Option	Type	Description	Default
`push-gossip-percent-stake`	float64	Percentage of total stake to push gossip to (range: [0, 1])	`0.9`
`push-gossip-num-validators`	int	Number of validators to push gossip to	`100`
`push-gossip-num-peers`	int	Number of non-validator peers to push gossip to	`0`

Regossip Settings

Option	Type	Description	Default
`push-regossip-num-validators`	int	Number of validators to regossip to	`10`
`push-regossip-num-peers`	int	Number of non-validator peers to regossip to	`0`

Timing Configuration

Option	Type	Description	Default
`push-gossip-frequency`	duration	Frequency of push gossip	`100ms`
`pull-gossip-frequency`	duration	Frequency of pull gossip	`1s`
`regossip-frequency`	duration	Frequency of regossip	`30s`

Logging and Monitoring

Logging

Option	Type	Description	Default
`log-level`	string	Logging level (trace, debug, info, warn, error, crit)	`"info"`
`log-json-format`	bool	Use JSON format for logs	`false`

Profiling

Option	Type	Description	Default
`continuous-profiler-dir`	string	Directory for continuous profiler output (empty = disabled)	`""`
`continuous-profiler-frequency`	duration	Frequency to run continuous profiler	`15m`
`continuous-profiler-max-files`	int	Maximum number of profiler files to maintain	`5`

Metrics

Option	Type	Description	Default
`metrics-expensive-enabled`	bool	Enable expensive debug-level metrics; this includes Firewood metrics	`true`

Security and Access

Keystore

Option	Type	Description	Default
`keystore-directory`	string	Directory for keystore files (absolute or relative path); if empty, uses a temporary directory at `coreth-keystore`	`""`
`keystore-external-signer`	string	Specifies an external URI for a clef-type signer	`""`
`keystore-insecure-unlock-allowed`	bool	Allow insecure account unlocking	`false`

Network and Sync

Network

Option	Type	Description	Default
`max-outbound-active-requests`	int64	Maximum number of outbound active requests for VM2VM network	`16`

State Sync

Note: If state-sync is enabled, the peer will download chain state from peers up to a recent block near tip, then proceed with normal bootstrapping. Please note that if you need historical data, state sync isn't the right option. However, it is sufficient if you are just running a validator.

Option	Type	Description	Default
`state-sync-enabled`	bool	Enable state sync	`false`
`state-sync-skip-resume`	bool	Force state sync to use highest available summary block	`false`
`state-sync-ids`	string	Comma-separated list of state sync IDs; If not specified (or empty), peers are selected at random.	`""`
`state-sync-commit-interval`	uint64	Commit interval for state sync (blocks)	`16384`
`state-sync-min-blocks`	uint64	Minimum blocks ahead required for state sync	`300000`
`state-sync-request-size`	uint16	Number of key/values to request per state sync request	`1024`

Database Configuration

WARNING: firewood scheme is untested in production. To use firewood, you must also set the following config options:

pruning-enabled: true (enabled by default)
state-sync-enabled: false
snapshot-cache: 0

Failing to set these options will result in errors on VM initialization. Additionally, not all APIs are available - see these portions of the config documentation for more details.

Option	Type	Description	Default
`inspect-database`	bool	Inspect database on startup	`false`
`state-scheme`	string	EXPERIMENTAL: specifies the database scheme to store state data; can be one of `hash` or `firewood`	`hash`

Transaction Indexing

Option	Type	Description	Default
`transaction-history`	uint64	Maximum number of blocks from head whose transaction indices are reserved (0 = no limit)	`0`
`skip-tx-indexing`	bool	Skip indexing transactions entirely	`false`

Warp Configuration

Option	Type	Description	Default
`warp-off-chain-messages`	array	Off-chain messages the node should be willing to sign	empty array
`prune-warp-db-enabled`	bool	Clear warp database on startup	`false`

Miscellaneous

Note: If skip-upgrade-check is set to true, the chain will skip verifying that all expected network upgrades have taken place before the last accepted block on startup. This allows node operators to recover if their node has accepted blocks after a network upgrade with a version of the code prior to the upgrade.

Option	Type	Description	Default
`acceptor-queue-limit`	integer	Specifies the maximum number of blocks to queue during block acceptance before blocking on Accept.	`64`
`gas-target`	integer	The target gas per second that this node will attempt to use when creating blocks	Parent block's target
`skip-upgrade-check`	bool	Skip checking that upgrades occur before last accepted block ⚠️ Warning: Only use when you understand the implications	`false`

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