Solana durable nonce deprecation: Anza and Vector

Solana Foundation is deprecating durable nonces. A normal transaction expires 150 blocks after its blockhash. A durable nonce swaps that for a stored value so the signed payload never expires. That special case leaves the runtime. Page: solana.com/upgrades/durable-nonce-deprecation. October 2026. Discussion SIMD #456. X @SolanaFndn.

The replacement is an offline signer program. The cold key signs a message with no blockhash. A hot fee payer wraps it in a normal transaction. The program verifies, advances its own nonce, and runs instructions via CPI with a PDA as signer. Two candidates: Anza Programmatic Signer (Devnet, pre-audit, spl-programmatic-signer CLI) and Blueshift Vector (IDs published, cluster not stated). No final pick. Removal is expected about six months after a replacement is ready. No date. Normal transactions are unaffected.

Custodians: test on Devnet now. Migrate authorities to a signer PDA while durable nonces still work. Programs that assert top-level stack height, introspect the instructions sysvar, or enable Token-2022 CPI Guard will lock these users out. Relayers drop AdvanceNonceAccount rules. RPC: getFeeForMessage nonce fallback goes away. Indexers: the acting signer is a PDA. June 2026: nonce txs were 3.1% of count and 30% of priority fees (SIMD #564).