How the Handoff Works
The date follows September’s testnet and devnet migrations, which opened an observation and integration-testing period before mainnet.
The mainnet feature gate—the switch enabling the upgrade—has not yet activated, according to the Foundation’s guide. Anza’s activation policy says mainnet activations for a new minor software version begin two full epochs after 95% of stake adopts that version.
The migration plan separates that switch from the handoff itself. The feature gate activates at an epoch boundary; 5,000 slots later, blocks temporarily stop carrying user transactions and contain only votes. Validators then establish an Alpenglow genesis certificate backed by 82% of stake, roll back the vote-only blocks after the selected genesis block, and resume user transactions under Votor.
Anza expects the handoff to take hundreds of milliseconds. The underlying migration proposal describes one slot as the optimistic duration; validators continue TowerBFT consensus while waiting for the required certificate.
What Operators Need to Change
Validators must run an Agave 4.3.0-based client before activation, the Foundation says. Firedancer and Frankendancer are not supported during the migration. Operators also need at least 0.8 SOL above the rent-exempt minimum in their vote accounts to pay a new per-epoch admission fee. That replaces vote-transaction fees previously paid from validator identity accounts.
Indexers and trading infrastructure consuming Geyser or gRPC streams must distinguish candidate blocks within a slot using `bank_id`, rather than grouping everything by slot alone. Systems merging feeds from several providers must reconcile by blockhash: `bank_id` is local to each node.
The `confirmed` and `finalized` commitment levels become equivalent after activation. The Foundation advises developers to move new code to `finalized` only after Alpenglow is live, and to reset transaction-count dashboards because votes disappearing from blocks can lower reported throughput without a drop in user activity.
For users, signing and sending transactions stay the same. The latency applications see can still depend on infrastructure: Anza’s operator documentation says nodes outside the admitted validator set may learn of finality from certificates in later blocks, rather than directly from Votor messages.
The Foundation tells developers to detect the actual migration through the new `getAgGenesisCert` RPC method, rather than a calendar date or software version. It returns `null` under TowerBFT and a genesis certificate once the network has migrated.
