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TLDR:
  • Helicon activated on Fuji Testnet on July 28, 2026 and activates on Avalanche Mainnet on September 22, 2026 at 15:00 UTC, with AvalancheGo v1.15.0.
  • Six Avalanche Community Proposals (ACPs) activate: ACP-194 (continuous execution), ACP-236 (auto-renewed staking), ACP-267 (uptime requirement increase), ACP-273 (reduce minimum staking duration), ACP-283 (dynamic minimum gas price), ACP-285 (reduce minimum consumption rate).
  • Helicon removes C-Chain RPC methods — the admin, warp, and personal namespaces, three eth methods, and eight non-trace debug methods.
  • On the C-Chain, latest and pending now resolve to the last executed block, and safe and finalized to the last settled block.
Helicon is a breaking upgrade for RPC users, unlike the Granite upgrade. A call to eth_accounts or to one of the removed debug methods fails on an upgraded node. Check your application against the removed methods listed on this page.

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Main article

Helicon is a network upgrade for Avalanche that changes how the C-Chain executes blocks and prices gas, and that removes a set of C-Chain RPC methods. Fuji Testnet activated Helicon on July 28, 2026, and Avalanche Mainnet activates it on September 22, 2026 at 15:00 UTC.

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Chainstack nodes are Helicon-ready

Chainstack rolls out Helicon on the Avalanche upgrade timeline: Fuji Testnet first, then Mainnet. Nodes on Chainstack are prepared for the respective network upgrades.
eth_call, eth_getLogs, eth_sendRawTransaction, eth_getBlockByNumber, the debug_trace* methods, and the X-Chain and P-Chain APIs are unaffected. For the full supported surface, see Avalanche methods.

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Removed API namespaces

Helicon removes three C-Chain namespaces entirely. A request to any method in these namespaces returns a method-not-found error on an upgraded node:
  • admin — node administration methods such as admin_peers and admin_nodeInfo. These were never served on Chainstack nodes.
  • warp — Avalanche Warp Messaging methods.
  • personal — account management methods.

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Removed C-Chain RPC methods

Helicon removes eleven individual C-Chain methods on top of the removed namespaces. Three eth methods that report node-local accounts:
  • eth_accounts
  • eth_coinbase
  • eth_etherbase
Eight debug methods for state and block inspection:
  • debug_accountRange
  • debug_dumpBlock
  • debug_getAccessibleState
  • debug_getBadBlocks
  • debug_getModifiedAccountsByHash
  • debug_getModifiedAccountsByNumber
  • debug_preimage
  • debug_storageRangeAt
The debug_trace* methods — debug_traceBlockByNumber, debug_traceBlockByHash, debug_traceTransaction, debug_traceCall, and debug_traceBlock — are not affected. Deploy your node in archive mode to call them, as described in Debug and trace APIs.
If your application reads contract storage with debug_storageRangeAt, you can replicate the query with eth_getStorageAt against known slot positions. See eth_getStorageAt vs debug_storageRangeAt on Reth for a working script — the same approach applies to Avalanche.

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Named block resolution on the C-Chain

ACP-194 makes C-Chain block execution continuous, so a block can be accepted before it is executed. That splits apart what the named block tags mean, and the tags resolve as follows on an upgraded node: The practical effect is that latest can lag block acceptance by the execution queue depth, and safe and finalized now return the same block. An application that reads state at latest and expects it to match the newest accepted block height needs to account for that gap — compare the height returned by eth_getBlockByNumber with latest against the height you get from a block subscription.

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Dynamic minimum gas price

ACP-283 replaces the fixed minimum C-Chain gas price with one that adjusts to network conditions. Read the current value with eth_gasPrice or eth_feeHistory rather than hardcoding a floor, and let eth_estimateGas size your gas limit.

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Deprecated with a warning

One RPC method is deprecated rather than removed, and still answers on an upgraded node:
  • avax.getAtomicTxStatus — replaced by avax.getAtomicTx.

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The six ACPs

Helicon activates six proposals. Four change validator economics and operations on the P-Chain, and two change C-Chain execution and pricing:

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What this means for developers

If you build on Avalanche using Chainstack nodes: Check your calls — replace the removed debug methods and drop any eth_accounts, eth_coinbase, or eth_etherbase call. A node endpoint has no accounts of its own, so these methods returned an empty or zero result before Helicon removed them. Re-read your block tags — if your indexer or bot treats latest as the newest accepted block, measure the gap against a block subscription and decide whether your application can tolerate it. Stop hardcoding a gas floor — query the minimum gas price at call time.
Last modified on September 9, 2026