Independent Solana validators adopted Anza’s Alpenglow protocol on Wednesday, Oct. 21, shifting the network to consensus software in Agave with a target of roughly 150 milliseconds to finalize blocks.
Anza built Alpenglow and incorporated it into Agave, its validator client, but the company could not make the networkwide change on its own: independent operators had to install compatible software. Anza was founded Jan. 30, 2024, by former Solana Labs executives and core engineers; Agave began as a fork of the Labs’ validator software. Solana’s explanation of the split said it would let Anza develop the client independently and help the network support multiple clients, including Jump Crypto’s Firedancer.
The Solana Foundation puts Alpenglow’s finality target at about 150 milliseconds, compared with about 12.8 seconds under TowerBFT. It describes that figure as an estimate informed by testing and the stake distribution at the time, so actual results can vary. The measurement concerns when a block is final, not how often blocks are produced.
The change took place in stages. Epoch 1064 began at about 9:36 a.m. ET (13:36 UTC), the Foundation said. TowerBFT remained in use during a 5,000-slot transition; Anza said Alpenglow took over consensus at slot 459,653,000 at about 10 a.m. ET (14:00 UTC).
Votor, Alpenglow’s active phase, forms certificates from votes exchanged among validators. A block can reach finality after one or two voting rounds. The Foundation said the upgrade kept the existing execution layer, program behavior, fee structure and Solana Virtual Machine intact.
Operators also faced migration conditions. The Foundation required an Agave-based client running version 4.3.2 and a vote account with at least 0.8 Solana (SOL) above its rent-exempt minimum each epoch to cover the Validator Admission Ticket fee. Firedancer and Frankendancer were not supported for this migration.
Anza said faster finality may help merchants and exchanges settle payments and deposits sooner. Anza CEO Brennan Watt called Alpenglow “the largest, most ambitious blockchain upgrade since 'The Merge.'”
Anza’s other named work remains at an earlier stage. Rotor is planned as a future overhaul of how block data moves through the network, but no release schedule has been set. Quantumglow remains research into adapting Alpenglow for post-quantum security, with no release date committed.
