Solana’s Agave 4.3 release schedule sets September 28 for mainnet-beta feature activation, when the Alpenglow consensus upgrade is slated to go live on the production network alongside SHA512 syscalls, big-integer modular exponentiation and a deeper CPI (cross-program invocation) limit. The timeline, published by Anza on August 12, came as a Teraswitch routing failure knocked 28.83% of staked SOL offline, a level still 4.5 percentage points below the one-third threshold that would stop finality under the current Tower BFT system. Solana co-founder Anatoly Yakovenko said Alpenglow can survive "to 40% down," underscoring the protocol’s higher tolerance for non-adversarial outages. The v4.3 branch was created on August 11, with testnet adoption targeted for August 17, validator rollout steps set for September 8 and September 14, and general adoption recommended on September 21. Validators must register a BLS public key (cryptographic validator identity key) on-chain before activation or they will be excluded from the Alpenglow consensus set. Anza said the schedule is tentative and all dates may change.