# Simplex BFT

*Tempo's Byzantine fault-tolerant consensus, implemented by Commonware.*

Deterministic sub-second finality with an explicit safety-over-liveness stance: it halts rather than risk a re-org.

## At a glance

- **Type:** protocol component
- **Category:** protocol-core
- **Status:** mainnet

## Key facts

- **Implemented by:** Commonware _(confidence 90%)_
- **Block time:** ~600ms, VRF leader election, deterministic finality _(confidence 85%)_
- **Liveness:** Halts if >1/3 validators unavailable (safety over liveness) _(confidence 85%)_

## Related entities

- [Tempo](https://tempo.dataos.so/entity/tempo) — builds on
- [Commonware](https://tempo.dataos.so/entity/commonware) — powered by

## Sources

1. [Tempo Docs: Consensus](https://docs.tempo.xyz) — Tempo Docs

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Last reviewed: 7 Jun 2025  
Canonical: https://tempo.dataos.so/entity/simplex-bft  
Source: tempowiki (https://tempo.dataos.so) — an independent, sourced reference for the Tempo ecosystem. Not affiliated with Tempo, Stripe, or Paradigm.