Espresso Mainnet Finality Time Reduced to Under One Second

Espresso (Espresso) has reduced its mainnet transaction finality time to under one second. Validators comprising approximately 100 participants implemented a network upgrade on September 9, revising consensus, network structure, block creation, and data availability mechanisms. The Espresso Foundation announced that after the September 9 mainnet upgrade, transaction finality time dropped to under one second. Network communication rounds required for finality decreased from over seven to three, and the reliance on leader node survival for block finality was eliminated.

The key change involves validator communication methods. Previously using CDN intermediaries and libp2p-based gossip networks, the network now employs Cliquenet, an encrypted fully connected mesh. This allows consensus messages to be transmitted in a single step between validators. Block creation also changed: previously handled by external services, block generation is now processed internally within leader nodes. For data availability, new erasure coding methods and optimized Reed-Solomon libraries were implemented, using BLAKE3 hash functions. Encoding, verification, and recovery processes are now parallelized.

The Foundation states that the workload for finality blocks—covering block creation, data availability, and voting—has decreased by approximately two-thirds, while hardware and bandwidth requirements for validator nodes have also been reduced. Espresso serves as a foundational layer for rollups to verify transaction order and state. Rollups process transactions on separate networks before settling results on upper chains like Ethereum (ETH). Finality and settlement are distinct processes: Espresso's finality confirms irreversible transaction sequencing, while upper-chain settlement involves additional validation. Therefore, the under-one-second finality time does not imply equivalent acceleration of upper-chain settlement.

This upgrade reflects internal network structure improvements aimed at faster state sharing between rollups and multiple chains. Rollups can process transactions and verify order on separate layers. In this architecture, the foundational layer's finality speed reduces the time required for multiple networks to confirm identical transaction states. Espresso previously achieved approximately 0.24 seconds of finality on its Decaf testnet before moving to mainnet deployment preparation. The transition from testnet performance to mainnet was identified as a subsequent step. Mainnet and testnet metrics differ due to varying node configurations and operational conditions, but this upgrade reflects the implementation of sub-second finality goals established during testing.