The Espresso Network is a Confirmation Layer that provides chain operators with information about the state of their own chain, as well as the states of other chains. These confirmations are important for cross-chain composability, which requires each chain’s full nodes to have access to reliable, credibly neutral confirmations of what’s happening on other chains in real time.

Chains of all kind (including rollups, validiums, L2s, L3s, and beyond) integrate Espresso to enable bridging protocols, solvers, applications, and users to benefit from fast, reliable confirmations. These confirmations form the foundation of various approaches to cross-chain composability.

Espresso confirmations are more secure than centralized sequencer confirmations because they are backed by BFT consensus among a decentralized set of operators, and they are significantly faster than waiting for Ethereum L1 finality—occurring in a matter of a few seconds rather than 15 minutes. Moreover, Espresso confirmations will be backed by economic security as the network transitions to proof-of-stake.

Espresso is run by a permissioned, decentralized network of node operators who participate in the consensus protocol (HotShot) and the data availability layer (EspressoDA). An upgrade planned for early 2025 will move the network to a permissionless proof-of-stake model.

Some chains use Espresso as a decentralized sequencing layer, but this is not a prerequisite of leveraging Espresso for confirmations. While this is technically a shared sequencing layer among rollups using Espresso this way, the Espresso Network does not yet support sophisticated cross-chain building to fulfill user intents. This functionality is planned for future releases contingent upon demand. Many chains integrating with Espresso continue to use their own centralized sequencer but improve their users' experience by offering fast, reliable confirmations via Espresso. For more on Espresso and modularity, you can read on here.

All chains using Espresso also benefit from highly efficient data availability offered by the Espresso Network. However, many of the chains that are using Espresso also choose to leverage another form of DA, such as EigenDA, Celestia, Avail, or Ethereum itself. We have designed Espresso to respect and to be additively compatible with these choices. For more on Espresso and modularity, you can read here.

Yes. Chains that are coordinating sequencing with other chains can still use Espresso independently of whether the entire collective does so and can opt in or out at any time.

Chains integrate Espresso to offer fast, reliable confirmations to their users. Some chains also use Espresso for decentralized sequencing or low-cost data availability.

Bridging protocols, solvers, relayers, and others leverage Espresso confirmations to have greater certainty as they make cross-chain guarantees.

Node operators run Espresso software and participate in consensus.

At Espresso, we divide our efforts into two categories:

• Espresso Product: building production-ready infrastructure that enables chains to coordinate and achieve composability with each other in an incentive-compatible way.
• Espresso Research: exploring the design space of cross-chain composability, developing proposals for potential new products, and testing ideas with collaborators.

Some of the proposals and designs explored by Espresso Research include: cross-chain builder marketplaces; shared sequencing; fast, secure cross-chain message-passing; and aggregated interoperability clusters. For Espresso Research proposals, see here. For Espresso Research discussion, go to our forum.

The Espresso Network relies on an implementation of state-of-the-art BFT consensus called HotShot. HotShot is purpose-built for providing fast confirmations in a manner that makes a different set of tradeoffs, and is therefore complementary, to the Ethereum L1's consensus. Specifically, HotShot is optimistically responsive, meaning it can support Web2 scale under normal networking conditions while sustaining Web3 levels of decentralization. For more on HotShot, see here.

Espresso is now running Mainnet 0. For more information on our roadmap, see our Roadmap post here. To get started using Espresso, see our docs here.

Get in touch with us here and check out our documentation here.

We are currently conducting permissioned onboarding of node providers.

Ultimately, Espresso's mainnet will be fully permissionless and you will be able to start running Espresso nodes or participating as a sequencer in the marketplace by following our documentation. Our early docs for node operators can be found here. Feedback is welcome.

To get the benefits of Espresso as a user, you need to be using a chain or application that leverages Espresso. The chains that do so can be found here. If the app or chain that you use does not yet use Espresso, you should let them know by posting about it on Twitter or Farcaster and tagging Espresso. We are always welcoming more chains and applications to our growing ecosystem of projects who believe in a seamless, unified on-chain user experience.