Helicon Upgrade

Helicon is a Primary Network upgrade that activates six Avalanche Community Proposals. It changes how the C-Chain executes blocks and prices gas, and it changes several Primary Network staking rules, including how long a validator can stake for, how much uptime it needs, and whether it has to re-stake at all.

Activation Status

What Changes

Staking Changes in Detail

Auto-Renewed Staking (ACP-236)

A validator can now specify a cycle duration and an auto-compound percentage instead of a fixed end time. At each cycle boundary the P-Chain settles rewards and starts the next cycle automatically. Three transactions are involved: AddAutoRenewedValidatorTx, SetAutoRenewedValidatorConfigTx, and RewardAutoRenewedValidatorTx, the last of which is issued by block builders rather than by you.

Renewal is conditional on reward eligibility, so a cycle that misses the uptime requirement ends the validation rather than renewing it. Delegation is unchanged and cannot auto-renew: a delegation must still fit inside the validator's current cycle.

See AVAX Staking for Professionals for the operational detail.

Uptime Requirement (ACP-267)

The threshold for earning rewards rises from 80% to 90%. This is not a genesis parameter change. The 90% figure is applied when the network decides reward eligibility for any Primary Network validation whose start time is at or after Helicon activation:

• A validation that started before activation is still judged against 80%.
• A validation that starts after activation needs 90%.
• Every cycle of an auto-renewed validator starts after activation, so auto-renewed validators are always held to 90%.
• Avalanche L1 validators are unaffected and keep the uptime requirement set by their own subnet transformation.

The reward model is unchanged in every other respect. It remains all or nothing, there is no partial payout, and there is no slashing: a validator that misses the threshold forfeits rewards but keeps its principal.

Minimum Staking Duration (ACP-273)

The minimum duration for a Primary Network validator drops from two weeks to 48 hours on Mainnet, and from 24 hours to 12 hours on Fuji. Custom networks default to one hour.

Delegators are not affected and keep the existing minimum. The maximum staking duration is unchanged at one year.

Minimum Consumption Rate (ACP-285)

MinConsumptionRate, the lower bound of the reward curve, drops from 10% to 7.5%. The change is phased in rather than applied at once: it ramps linearly over the 90 days following activation, and the rate applied to a staking period is the one in effect at that period's start time. A stake starting 45 days after activation therefore uses roughly 8.75%.

MaxConsumptionRate is unchanged, so the effect is concentrated on short staking periods. See the staking rewards formula for how the two bounds combine.

What You Need to Do

Validators on Fuji. Upgrade to AvalancheGo v1.15.0-fuji or later. Then check that your node clears 90% uptime rather than 80%, since any validation you start now is judged against the higher threshold. Call info.uptime on your own node and cross-check against the validator health dashboard, because a single node's view of its own uptime can be misleading.

Validators on Mainnet. Upgrade to AvalancheGo v1.15.0 before September 22, 2026 at 15:00 UTC. A node still on an older release when Helicon activates will not follow the upgraded chain. Plan for the uptime threshold as well: any validation you start on or after activation is judged against 90% rather than 80%, and validations already running keep the 80% requirement.

C-Chain developers. ACP-194 changes when state is available relative to block acceptance, and several C-Chain RPC namespaces are deprecated alongside it. Read Streaming Asynchronous Execution and the v1.15.0 release notes before assuming existing behavior holds.

Exchanges and custodians. The staking minimums and the uptime threshold both move. If you quote a two-week minimum staking period to users, that number becomes 48 hours on Mainnet on September 22, 2026.