Helicon: Continuous Execution & Auto-Renewed Staking | Fuji Pre-Release

Please note that this release is unable to run mainnet - and will display "mainnet is not supported" if attempted to run with a mainnet configuration.

This release schedules the activation of the following Avalanche Community Proposals (ACPs):

• ACP-194 C-Chain Async Execution
• ACP-236 Auto-Renewed Staking
• ACP-267 Validator Uptime Requirements Increase
• ACP-273 Reduce Minimum Validator Staking Duration
• ACP-283 Dynamic Minimum C-Chain Gas Price
• ACP-285 Reduce Minimum Consumption Rate

The ACPs in this upgrade go into effect at 11 AM ET (3 PM UTC) on Tuesday, July 28th, 2026 on the Fuji Testnet.

All Fuji nodes must upgrade before 11 AM ET, July 28th 2026.

APIs

The wallet now supports the transaction types:

• NewAddAutoRenewedValidatorTx
• NewSetAutoRenewedValidatorConfigTx

C-Chain RPCs

• All RPCs that rely on state, if called after a block is accepted, will return after the block is executed.
• The admin API namespace is deprecated.
• The warp API namespace is deprecated.
• The avax.getAtomicTxStatus RPC is deprecated.
• All APIs that rely on state of pending blocks is deprecated.
• In the debug namespace, the following APIs are deprecated:
  • debug_dumpBlock
  • debug_preimage
  • debug_getBadBlocks
  • debug_accountRange
  • debug_storageRangeAt
  • debug_getModifiedAccountsByNumber
  • debug_getModifiedAccountsByHash
  • debug_getAccessibleState

Metrics

• Histogram avalanche_snowman_consensus_latencies creates 8 buckets instead of 4, each a second wide.
• Added avalanche_evm_sae_last_executed_height and avalanche_evm_sae_last_settled_height gauges, exposing SAE async-execution and settlement heights.
• Added SAE execution-pressure metrics:
  • avalanche_evm_sae_execution_queue_duration_seconds (histogram): time from a block's acceptance into the execution queue until its execution completes.
  • avalanche_evm_sae_execute_block_duration_seconds (histogram): wall-clock time to execute a single block, including state commit and post-execution work.
  • avalanche_evm_sae_execution_queue_blocks (gauge): number of accepted blocks that have not yet completed execution.
  • avalanche_evm_sae_execution_queue_gas_limit (gauge): sum of the gas limits of accepted blocks that have not yet completed execution.
  • avalanche_evm_sae_executed_gas_charged_total (counter): cumulative gas charged by executed blocks (transaction gas used plus end-of-block operation gas).
  • avalanche_evm_sae_executed_gas_limit_total (counter): cumulative gas limit (worst-case gas) of executed blocks.
• Added avalanche_evm_sae_in_memory_blocks (gauge): number of SAE blocks still live in memory (created but not yet garbage collected).
• Added avalanche_evm_sae_accepted_gas_limit_total (counter): cumulative gas limit (worst-case gas) of blocks accepted into the execution queue; the acceptance-side counterpart of executed_gas_limit_total.
• Added SAE gas-time and pricing metrics:
  • avalanche_evm_sae_last_executed_gas_time_seconds (gauge): gas time reached by the latest executed block, as a Unix timestamp.
  • avalanche_evm_sae_gas_time_wall_time_gap_seconds (gauge): gas time minus wall time, observed when the latest block finished executing; negative when gas time lags the wall clock.
  • avalanche_evm_sae_worst_case_base_fee (gauge): worst-case base fee admitted by consensus for the latest enqueued block.
  • avalanche_evm_sae_executed_base_fee (gauge): base fee realized by execution of the latest executed block.
  • avalanche_evm_sae_worst_case_gas_excess (gauge): worst-case gas excess admitted by consensus for the latest enqueued block.
  • avalanche_evm_sae_executed_gas_excess (gauge): gas excess realized by execution of the latest executed block.
  • avalanche_evm_sae_gas_target (gauge): ACP-176 gas target in force as of the latest enqueued block.
• Added avalanche_evm_cchain_min_block_delay_seconds (gauge): ACP-226 minimum block delay currently in force, taken from the most recently executed block.
• Renamed Coreth and Subnet-EVM state-sync p2p metrics:
  • avalanche_{vmName}_eth_net_tracked_peers -> avalanche_{vmName}_sdk_sync_peer_tracker_num_tracked_peers
  • avalanche_{vmName}_eth_net_responsive_peers -> avalanche_{vmName}_sdk_sync_peer_tracker_num_responsive_peers
  • avalanche_{vmName}_eth_net_average_bandwidth -> avalanche_{vmName}_sdk_sync_peer_tracker_average_bandwidth

NOTE: {vmName} is evm for Coreth/C-Chain and subnetevm for Subnet-EVM chains

Configs

New

• helicon-min-stake-duration (only on local networks)
• min-price-target for C-Chain

Deprecated in C-Chain

• skip-upgrade-check
• admin-api-enabled
• admin-api-dir
• warp-api-enabled
• continuous-profiler-dir
• continuous-profiler-frequency
• continuous-profiler-max-files
• rpc-gas-cap
• rpc-tx-fee-cap
• trie-dirty-cache
• trie-dirty-commit-target
• trie-prefetcher-parallelism
• preimages-enabled
• snapshot-wait
• snapshot-verification-enabled
• accepted-queue-limit
• populate-missing-tries-parallelism
• prune-warp-db-enabled
• historical-proof-query-window
• metrics-expensive-enabled
• price-options-slow-fee-percentage
• price-options-fast-fee-percentage
• price-options-max-tip
• tx-pool-price-limit
• tx-pool-price-bump
• tx-pool-lifetime
• api-max-duration
• ws-cpu-refill-rate
• ws-cpu-max-stored
• allow-unfinalized-queries
• allow-unprotected-tx-hashes
• keystore-directory
• keystore-external-signer
• keystore-insecure-unlock-allowed
• push-gossip-percent-stake
• push-gossip-num-validators
• push-gossip-num-peers
• push-regossip-num-validators
• push-regossip-num-peers
• push-gossip-frequency
• pull-gossip-frequency
• regossip-frequency
• log-level
• log-json-format
• enable-db-inspecting-api
• enable-profiling-api
• offline-pruning-bloom-filter-size
• max-outbound-active-requests
• state-sync-skip-resume
• state-sync-server-trie-cache
• state-sync-commit-interval
• state-sync-min-blocks
• state-sync-request-size
• inspect-database
• accepted-cache-size
• state-history
• skip-tx-indexing
• http-body-limit
• batch-response-max-size

Features

• Subnet-EVM allows providing the initial block delay at genesis via InitialMinDelayMS in the chain config.
• Add transitionvm as a type of VM that can swap between two different implementations at a specific fork.

Fixes

• Updated minimum Go version from v1.25.8 to v1.25.10.
• Archival nodes with re-execution will correctly skip atomic transaction application.
• Fixed bug where code syncer could finish with improper disk artifacts.
• P-Chain ERROR logs during close are downgraded to WARN.

Full Changelog: v1.14.2...v1.15.0-fuji