Agave 4.2 Release Overview

Agave 4.2 Release Overview

August 2026 • Solana Foundation

Agave 4.2 is the next release of Anza's Solana validator client, recommended for mainnet adoption in August 2026 with feature activations expected to start the week of August 17, per the v4.2 release schedule. The release carries three feature-gated upgrades: a 90% rent reduction, larger transaction sizes, and reduced slot times. The release also includes the necessary code to run Alpenglow, allowing core developers and validators to test Alpenglow in a community test cluster. Alpenglow will not be activated on mainnet in Agave 4.2, but it will be thoroughly tested for an expected Agave 4.3 release.

Technical Details

Reduced Rent

SIMD-0437 cuts lamports_per_byte, the constant behind Solana's fully refundable storage bond, from 6,960 to 696 — a 90% reduction. The cut rolls out across five independent feature gates so core developers can monitor state growth at each step, with a fallback gate that can restore the current value if needed.

This means creating on-chain state gets dramatically cheaper: the rent deposit for a standard SPL token account falls from about $0.159 to $0.0159, making it practical for businesses to cover rent on behalf of their users at scale.

Read the full article: Reduced Rent

Larger Transaction Sizes

SIMD-0296 raises the maximum transaction size from 1232 bytes to 4096 bytes, delivered through the new transaction v1 format. Existing v0 and legacy transactions continue to work unchanged; applications opt in by adopting v1.

This means workloads that never fit inside a single transaction, such as ZK proofs, large multisigs, and on-chain signature schemes like BLS, can now land as one atomic transaction instead of being stitched together with lookup tables or bundles. Indexers that decode raw transaction bytes will need to recognize the new transaction v1 layout.

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Reduced Slot Times

SIMD-0525 halves Solana's slot time from 400ms to 200ms, rolled out in four 50ms decrements gated by successive feature activations. The network will not advance to the next decrement if block skip rates are too high.

This means users see confirmations twice as fast, market makers can quote tighter spreads, and each leader's monopoly over block building narrows — improving both latency and censorship resistance.

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Alpenglow: Feature Complete, Activating in 4.3

Agave 4.2 contains the code changes for Alpenglow, Solana's cutting-edge new consensus protocol, but core engineers will be doing more testing and hardening of the code base. Alpenglow will not be activated in 4.2: activation is expected in Agave 4.3, the following release, targeted for October 2026.

Alpenglow replaces TowerBFT with the Votor voting algorithm, targeting roughly 150ms finality compared with today's 12.8-second TowerBFT finality. It eliminates vote transactions entirely. With Alpenglow, validators will exchange votes directly. Votor will tolerate 20% of stake being offline plus 20% of stake being adversarial. This means validators running 4.2 already carry the complete Alpenglow code, setting the network up for the consensus migration in the next release.

Read the full article: Alpenglow

About This Upgrade

Agave 4.2 delivers major improvements across three axes: cheaper on-chain state through the rent reduction, more capable transactions through the 4096-byte v1 format, and lower latency through 200ms slot times. Just as importantly, with Alpenglow feature-complete, the 4.2 release sets the stage for the largest protocol change in Solana's history, coming in Agave 4.3.

Learn more: Solana Upgrades