Finality
Also called deterministic finality, block finality
Origin:
composes, a standard BFT-consensus concept, not a Solidus invention. Solidus status:testnet, deterministic and live on the public network; a much faster figure exists only as a single-machine benchmark of undeployed code.
Finality is the point past which a committed block cannot be reversed. It matters because not every blockchain gives you that guarantee immediately: proof-of-work chains like Bitcoin only offer probabilistic finality. A block gets safer the more blocks are mined on top of it, but in principle a long enough alternate chain could still displace it. BFT-style consensus protocols (see BFT) instead offer deterministic finality: once a supermajority of the validator committee has certified a block through enough rounds, it is mathematically guaranteed never to be reverted, full stop, no "wait for more confirmations" needed.
Where it comes from
Deterministic finality is a property of BFT consensus generally, not something specific to any one project, it falls directly out of the same quorum-certificate math used by PBFT, Tendermint, and the HotStuff family. Solidus's engine achieves it the HotStuff way: a block finalizes once a chain of consecutive quorum certificates has formed on top of it (three certificates in the original design, two in the newer HotStuff-2 variant).
What "final" means on Solidus today
On the live public testnet, a block is deterministically final, no reorgs, no waiting for confirmations, once the 3-chain commit rule is satisfied, at a block cadence of roughly 2.5 seconds. That's real, running behavior on rpc.solidus.network today.
Separately, a newer HotStuff-2 consensus core (not yet deployed to the public network) has been benchmarked at single-digit-millisecond finality, a median of 7.6ms and a 99th-percentile of 11.5ms across 600 observations. That number is worth being precise about: it was measured on one Apple M4 machine, over local loopback, not across a real network with real latency between geographically separated validators. It describes what the new engine can do in a best-case, zero-network-latency environment, not a claim about how fast the live, deployed testnet is, and not a geo-distributed figure, because none exists yet.
Check it yourself
The public protocol repository's docs/bench/2026-07-13-apple-m4/ directory contains the raw logs and exact commands behind the loopback measurement: a stranger with comparable hardware could attempt to reproduce it directly.
Related terms: HotStuff · BFT · Committee Election
Where it comes from
Someone else specified this. Solidus assembles it.
Finality (the point at which a committed block is guaranteed never to be reverted) is a standard concept in BFT-style consensus theory. It's what distinguishes chains like this one, which finalize deterministically once a quorum certificate chain forms, from probabilistic-finality proof-of-work chains, where a block only becomes safe after enough later blocks pile up on top of it. Solidus doesn't originate the concept; its HotStuff-based engine composes it via a quorum-certificate chain rule.
How to check this
Running on the test network. Not mainnet.
docs/bench/2026-07-13-apple-m4/ in the public protocol repository carries the raw logs and exact commands behind the loopback finality measurement, reproducible by a stranger with the same hardware profile.