SIMD-0437 Step 1 Goes Live on Solana Mainnet, Beginning a Five-Phase Rent Reduction

Step 1 of SIMD-0437 activated on Solana SOL$101.58+2.8%Solana's mainnet on September 3, cutting lamports_per_byte from 6,960 to 6,333 and opening a five-step plan that targets a 90% reduction in on-chain storage costs once all phases complete.

Tim Garcia, a developer relations engineer at the Solana Foundation, announced the activation the previous evening, writing that "rent is getting cheaper on Solana starting tomorrow" and linking to Solana's Agave 4.2 upgrade overview, which confirms the rent reduction as a core mainnet feature of the release.

What lamports_per_byte Controls and Why It Matters

lamports_per_byte is the constant that determines how much SOL must be locked to keep a Solana account rent-exempt. The figure dates to Solana's early mainnet period. As SOL's price has risen substantially since then, the real-dollar cost of opening new accounts has risen with it, becoming more expensive than competing chains by measures the proposal's author, AnzaAnza engineer Igor Durovic, found unjustified by actual resource consumption.

Rent on Solana is a refundable deposit, not a recurring fee. The SOL locked to maintain an account is returned in full when the account is closed. What step 1 changes is how much new accounts must commit from activation onward. Existing accounts are unaffected.

The step 1 reduction moves lamports_per_byte from 6,960 to 6,333, a ~9% decrease. When all five steps complete, the rent-exempt deposit for a standard SPL token account falls from roughly $0.159 to $0.0159, per the Agave 4.2 upgrade overview.

Five Independent Feature Gates, One Phased Reduction

SIMD-0437 distributes the full 90% cut across five independent feature gates under Agave 4.2, allowing core developers to monitor state growth at each step before proceeding to the next. A sixth fallback gate can restore the original value if needed.

When Anza announced the testnet activation of step 1 on August 27, the team framed the end state: "lamports_per_byte drops 6,960 → 696. A token account's rent-exempt deposit goes from ~$0.16 to ~$0.016. Cheaper accounts = cheaper deployments."

The full five-step schedule, per the SIMD-0437 proposal:

Who Benefits From Cheaper Token Accounts

The cost reduction touches every part of the Solana ecosystem that opens accounts at scale. Wallet providers that fund accounts for new users at signup, DeFi protocols that open accounts on behalf of users during onboarding, NFT platforms that open at least one token account per mint, and payment apps targeting large user bases all pay this deposit in aggregate.

At the full 90% end state, creating one million token accounts requires roughly $15,900 in locked capital rather than $159,000 (at the $0.0159 versus $0.159 per-account deposit rates cited in the upgrade overview), a saving that matters most to applications with high account-creation volume.

Step 1 alone delivers the opening ~9% of that total saving, but it also establishes the monitoring baseline the Anza team will use to assess whether state growth warrants moving to step 2.

State Growth Risk and the Phased Rollout

Lower storage costs reduce the friction on creating new accounts, which carries a theoretical risk of encouraging spam. The phased structure is designed to give the network a data-driven pause between each activation. The SIMD-0437 proposal also notes that SIMD-0392 provides a backstop: rent can be increased back to the legacy value if state growth trends warrant a course correction.

SIMD-0437 Is One of Three Agave 4.2 Feature-Gate Upgrades

SIMD-0437 is one of three feature-gated upgrades in Agave 4.2, alongside Transaction V1 (SIMD-0385), which raises the maximum transaction size from 1,232 to 4,096 bytes, and a four-step slot time reduction under SIMD-0525 targeting 200ms block times. All three are independently gated and activate on separate schedules within the same release.

Steps 2 Through 5 Have No Announced Dates

The remaining four reductions carry no scheduled activation dates. Each requires its own feature gate and an Anza decision point based on the state data observed after the prior step. The pace of the full reduction depends on what the network shows at each stage.

Solana Compass covered step 1 activating on testnet on August 28, and the forecast for the mainnet timing was reported the day after.