Anza Names Agave v4.3.2 the Recommended Release for All Solana Validators Five Days Before Alpenglow

Anza told Solana's mainnet-beta validators on 16 October 2026 that Agave v4.3.2 is now "the recommended version for all validators" and to "Upgrade now." The Anza post arrived five days before Solana is scheduled to switch its consensus to Alpenglow at epoch 1064 on 21 October, and Anza said the release carries "important performance and stability fixes for Alpenglow." The v4.3.2 release went up on GitHub at 22:20 UTC on 15 October, labelled a stable build suitable for Testnet, Devnet and Mainnet Beta.

This is the second "upgrade now" call of the v4.3 cycle. Anza issued the first on 21 September, when it made Agave v4.3 the recommended version for all validators three days after v4.3.0 shipped on 18 September, according to Anza's releases page. The new call moves the recommended build to a later patch within the same line. Anza's post does not describe v4.3.2 as mandatory, and neither the release notes nor the Solana Foundation's migration page name it as a new minimum.

What changed in Agave v4.3.2 since v4.3.0

The Agave v4.3.2 release notes list every change merged since v4.3.0, including the version bump to 4.3.1, so they cover the full gap between the September build and this one. Three items carry the Alpenglow label: transaction buffering now uses Alpenglow's slot timing, that timing now works on Windows, and an unreliable Alpenglow equivocation test was fixed.

The changes merged after the 4.3.1 bump sit mostly on the voting and staking paths. Agave now serialises and deserialises vote state faster, lets BLS certificate verification (the signature checks Alpenglow uses to agree on blocks) run on an optional thread pool, tightens how the stakes cache checks accounts, and avoids an unnecessary memory allocation when creating vote reward accounts. Votes remain most of Solana's traffic until Alpenglow takes them out of blocks: from 10 to 15 October, the network carried about 264 million to 266 million vote transactions a day against 144 million to 173 million other transactions, per our network analytics. The rest is dependency and security housekeeping, such as vendoring the quinn networking library for advisory RUSTSEC-2026-0339, plus CI, test and ledger-tool fixes that do not touch a running validator.

The release notes are terse and do not explain which of these changes Anza had in mind when it described the fixes as important for Alpenglow.

Jito-Solana v4.3.2-jito says upstream v4.3.1 was abandoned

Jito JTO$0.463-0.4% published a matching build the same day. The Mainnet v4.3.2-jito release, marked as a pre-release when we checked on 16 October, pulls in the upstream Agave changes and says: "Upstream v4.3.1 was abandoned; operators on v4.3.1-jito or v4.3.0-jito.x should move to this release ahead of the Alpenglow activation." Jito lists no CLI flag, geyser plugin interface or toolchain changes against v4.3.1-jito.

That fills a gap Jito flagged a week earlier. Its BAM changelog of 9 October recommended v4.3.0-jito.0 for mainnet and noted that Anza and the Solana Foundation "have not yet specified the mainnet transition version." The same changelog said all mainnet BAM (Block Assembly Marketplace) nodes go into Maintenance Mode in the days before activation and told operators not to run FireBAM during the transition, as we covered in Jito's Alpenglow plan for BAM.

Alpenglow epoch 1064 requirements for Solana validators

The Solana Foundation's Alpenglow upgrade page still sets the floor at Agave 4.3.0. Validators need Agave, Jito-Solana or Harmonic Salsa "on a release built on Agave 4.3.0," and must hold at least 0.8 SOL above the rent-exempt minimum in their vote account to cover the Validator Admission Ticket. Firedancer and Frankendancer "are not supported during the migration," so validators on those clients have to change to an Agave-based build before the migration.

The Foundation page puts the start of epoch 1064 at about 15:00 UTC on Wednesday 21 October, with Alpenglow taking over at slot 459,653,000 roughly 18 minutes later. When Anza set the mainnet date, its 13 October post said Alpenglow goes live at about 14:50 UTC. Since 200ms slots arrived at epoch 1053, each epoch through 1058 has run about 26 hours, according to Solana Compass epoch data, and epoch 1059 was about half done when Anza posted. That leaves operators fewer than five epochs to roll out the patch. Stakers who want to know what their validator runs can see which client each validator reports on Solana Compass.