SIMD-0723, filed on GitHub on November 5 by Gabe Rodriguez of Anza, the team that maintains Solana's primary validator software, asks the network to retire the durable nonce — the mechanism that lets a signed transaction bypass blockhash expiry and remain valid weeks after signing. The proposal sets a May 2027 target for the feature's retirement.

What the durable nonce does

On Solana, a conventional transaction must reference a recent blockhash and becomes invalid once that blockhash drops out of the network's recent-history window, typically within about a minute or two of signing. The durable nonce was introduced to remove that constraint: a designated on-chain account stores a nonce value that serves as a non-expiring stand-in for a blockhash, allowing a transaction to be signed in advance — for example on an offline machine — and submitted days or weeks later while still being accepted as valid.

If adopted, SIMD-0723 would remove that capability, meaning signed transactions would once again be bound by the standard blockhash expiry window. For the use cases the durable nonce was introduced to serve — pre-signing on an offline machine followed by delayed submission — that would put submission back inside the same roughly minute-or-two window as ordinary transactions. The May 2027 target means the change would not be immediate even if the proposal advances.

Who filed the proposal

Anza is the development firm staffed by former Solana Labs engineers that maintains Agave, Solana's primary validator client implementation. Proposals authored by Anza engineers carry particular weight in Solana's upgrade process because they describe changes to the reference software that network validators run.

How SIMD changes take effect

Solana Improvement Documents (SIMDs) are the network's open process for proposing protocol modifications. Proposals are published on GitHub for public review and discussion, and changes that gain sufficient support are activated through Solana's validator voting mechanism, in which validators signal approval on-chain before a feature is enabled across the network. SIMD-0723 now sits at the start of that path: it is open for public review and discussion on GitHub, and its May 2027 retirement target would only take effect if the change gains sufficient support and is approved through validator voting.

Attribution

This report was first published by COINOTAG: Anza's Solana (SOL) Proposal SIMD-0723 Targets Durable Nonce End in May 2027