Anza Sets Solana Alpenglow Mainnet-Beta Date for October 21

150 milliseconds is the finality target Anza has set for the Alpenglow protocol once it activates on Solana mainnet-beta.

Anza plans to switch Solana mainnet-beta to the Alpenglow consensus protocol on Oct. 21, 2026, aiming for finality of about 150 milliseconds. NFA.

Announcement Timing

Anza posted the mainnet-beta date on X on Oct. 13, 2026. The post stated that Alpenglow goes live on mainnet-beta Wednesday, October 21, at about 14:50 UTC. This announcement came after testnet and devnet phases had already concluded.

Current Status

Alpenglow is not yet active on mainnet-beta. The protocol remains in the scheduled phase only. Validators and node operators must prepare clients ahead of the single-slot migration window.

Replacement Details

Anza says Alpenglow replaces TowerBFT, the consensus protocol Solana has run since genesis. The new system moves votes off chain, which leaves more room for user transactions. Its Votor voting protocol runs two voting modes at the same time.

Migration Plan

Anza says the switch is planned to happen in one slot after about 18 months of work. The migration aims to cut finality from seconds to about 150 milliseconds. No earlier date applies to mainnet-beta.

Network Rollout Sequence

Anza’s Alpenglow page shows testnet on Sep. 24 and devnet on Sep. 25. Solana’s upgrade page states Alpenglow activated on devnet at epoch 1167 on Sep. 25, 2026. These earlier stages preceded the announced mainnet-beta date.

Validator Requirements

Validators must run an Agave-based client such as Agave, Jito-Solana or Harmonic Salsa on a release built on Agave 4.3.0. Firedancer-based clients are not supported during the migration. This client rule applies specifically to the transition period.

Go-Live Calendar

Anza has scheduled the mainnet-beta activation for October 21, 2026 at about 14:50 UTC. The protocol is not live until that calendar date arrives. Plans remain subject to the single-slot migration process described in the announcement.

The upgrade focuses on reducing finality time while maintaining Solana’s existing validator framework. Operators should verify client versions match the stated Agave 4.3.0 baseline before the scheduled window.