INTRODUCTION

Espresso is a global confirmation layer that provides L2 chains with fast, reliable transaction confirmations backed by BFT consensus.

Espresso confirmations can improve cross-chain composability, as they provide chains with near-instant access to reliable, credibly neutral information about what’s happening not just on their own chain, but on all chains plugged into the network. Espresso's confirmation layer can prevent sequencer equivocation, protect against reorgs, and reduce finality risk for solvers in intent-based systems. Its versatility means chains can also use it as a decentralized sequencer and low-cost data availability layer.

The Espresso Network is currently in its Mainnet 0 release and supports applications by providing the following functionality:

1. Fast confirmations: HotShot, the consensus protocol used by the Espresso Network, confirms transactions within a few seconds. This enables bridges to move assets from chains integrated with Espresso at high speeds with minimal risk. Chains can maintain a centralized sequencer while opting in to Espresso for stronger confirmations.

2. Decentralized sequencing: 100 nodes will be running the Espresso Network in a decentralized manner during Mainnet 0. Rollups can opt into having their transactions sequenced by this group of 100 nodes, instead of using their own centralized sequencer. We plan to quickly scale the number of participating nodes and enable permissionless proof-of-stake-based participation following the Mainnet 0 release.

3. Low-cost data availability: Espresso offers applications a cheaper alternative to Ethereum for DA. Any integration with Espresso can take advantage of Espresso's strong data availability guarantee to improve its scalability.

Chains and applications can quickly get started with using Espresso following these general integration steps. For the easiest deployment experience, we are also actively contributing to integrations for the following stacks:

• Arbitrum Orbit chains

• Cartesi applications

• OP stack chains

• Polygon CDK

If you don't see your stack listed above, or if you'd like to help improve our current integration work, please get in touch with us here! You can also explore our high level integration guides if you'd like to start working on your own integration.

• ZK rollup

• Optimistic rollup

If you're a chain or application looking to enable faster bridging using Espresso confirmations, click here.

To learn more about the inner workings of the Espresso Network, please read this section of the docs.

In our documentation we generically refer to chains, rollups and L2s, but Espresso supports any kind of application that requires fast confirmations, transaction ordering, and/or data availability.