Frequently asked questions

Espresso is a layer 1 purpose-built to provide secure consensus, instant settlement, and sub-second finality to other chains and onchain applications. As opposed to legacy infrastructure, which was never designed as a base layer, Espresso runs a custom consensus protocol designed to provide integrated chains with sub-second transaction finality and high-throughput data availability. This empowers integrated chains to focus on execution and creating unique user experiences while gaining the speed, security, and interoperability capabilities they need to achieve their full potential.

It consists of a decentralized network of validators that run a custom BFT consensus protocol called HotShot. Rather than having a fixed blocktime, HotShot finalizes blocks as fast as the network allows (e.g. immediately once the leader receives votes from two-thirds of active stake). This enables Espresso to finalize the transaction ordering and data availability of a layer 2's block in under a second, offering the sub-second, secure finality a layer 1 like Ethereum is unable to provide. Espresso does not handle execution.

Espresso's finality enhances a layer 2's security by preventing sequencer equivocation (i.e., sending different versions of the same block to different parties) through a protocol-level restriction that ensures only Espresso-finalized blocks can be published downstream. This means other layer 2s, onchain apps, protocols, etc., can read a layer 2's state from Espresso and safely act upon it without waiting 12+ minutes for layer 1 settlement. Espresso can also be used on its own as a secure settlement option for layer 2s.

Chains that integrate with Espresso post their blocks to Espresso, which reaches consensus on their ordering. Once finalized, that state is immediately readable by any party: other chains, bridges, exchanges, solvers, or applications, enabling real crosschain composability without bridges introducing new trust assumptions.

Throughout this, chains keep their own sequencer and order their own transactions independently, retaining full sovereignty. Espresso provides BFT consensus on the ordering those sequencers have already determined, plus data availability. It's essential infrastructure that provides sub-second, BFT-secured finality for chains, not a replacement for their sequencers.

Layer 2s today face critical limitations: they’re forced to wait for their layer 1's finality, for example 12+ minutes when using Ethereum as that layer 1, and lack seamless interoperability with other layer 2s, protocols, and onchain apps. These challenges limit the crosschain experiences layer 2s can offer today.

A purpose-built base layer like Espresso solves these fundamental infrastructure gaps that other layer 1s weren’t built to address.

Espresso is designed for institutions moving financial assets onchain, and for the broader ecosystem of chains and applications that support them:

Financial Institutions: Issuers, payment networks, and fund and collateral managers run dedicated execution environments on Espresso for tokenized assets, stablecoins, payments, and collateral workflows, settling through Espresso's finality while staying connected to broader onchain liquidity. Learn more about specific use cases here.

Layer 2s and Chains: Various layer 2s across different tech stacks integrate with Espresso, including Arbitrum Orbit chains, OP Stack chains, and app-specific chains built for institutional use cases, regardless of VM or where they settle.

App Developers and Interoperability Infrastructure: Developers, bridges, exchanges, relayers, and solvers read layer 2 state derived from Espresso's finality through standard RPC interfaces, enabling real-time crosschain composability in under a second, instead of waiting 12+ minutes for layer 1 finality.

Espresso provides BFT consensus-backed transaction finality in under a second rather than the 12+ minutes required when layer 2s communicate via a layer 1 like Ethereum. This enables:

• Sub-second, secure finality: Transactions finalize in under a second, backed by BFT (Byzantine Fault Tolerant) consensus among a decentralized validator set rather than the assurances of a single centralized sequencer (operator), giving institutions a settlement guarantee they can act on immediately instead of waiting out a confirmation window
• Stronger settlement integrity: Prevents sequencer equivocation and protects against reorgs by ensuring layer 2s can only settle blocks that match what Espresso has already finalized
• Reduced capital lockup: Bridges, market makers, and liquidity providers can rely on Espresso's finality instead of holding capital against slow settlement windows
• Real-time visibility across chains: Institutions, applications, and counterparties gain immediate insight into the state of all connected chains, supporting audit and risk workflows
• Lower settlement risk: Espresso's finality creates fast, verifiable state commitments that institutions and counterparties can rely on for reconciliation across systems

These benefits transform isolated execution environments into a unified, verifiable ecosystem where value and data move seamlessly between chains.

Espresso is run by a permissionless, geographically distributed set of validators that participate in Espresso's consensus protocol (HotShot) and data availability.

Sub-second finality reduces the capital institutions must hold against settlement risk when trading or moving liquidity across chains (DeFi), and lays the groundwork for atomic crosschain transactions, where a multi-leg trade either settles completely or not at all, without one leg completing while the other fails. Institutions and market makers can move capital across chains without waiting out lengthy settlement delays, and liquidity providers (LPs) can operate more efficiently across multiple connected chains.

Espresso enables crosschain applications that aren't possible with current slow infrastructure. For institutions, this includes atomic delivery-versus-payment across chains (where a multi-leg trade either settles completely or not at all), real-time pricing and liquidity visibility across venues, and moving tokenized assets across chains without taking on bridge risk. The same finality also enables crosschain order books, bridgeless asset transfers (minting), unified experiences spanning multiple layer 2s, and real-time crosschain arbitrage.

There are three main ways to work with Espresso:

• Build on Espresso: Teams building app-specific chains and layer 2s can build upon Espresso’s base layer to settle directly to Espresso and benefit from true finality and data availability.
• Read from Espresso: Other chains, bridging protocols, exchanges, solvers, relayers, and others can read from Espresso to gain real-time insights into activities happening on integrated chains that they can safely act upon.
• Validate on Espresso: Node operators run Espresso software and participate in HotShot consensus. Espresso's validator set is permissionless.

Espresso is additive: layer 2s can keep their existing architecture while gaining true finality and composability benefits. Integrated layer 2s send their transaction batches to Espresso first, where its validators provide sub-second finality, rather than relying on a centralized sequencer's confirmations. Layer 2s can settle directly to Espresso, and separately keep whatever bridges they choose to maintain to Ethereum or elsewhere. All layer 2s that integrate with Espresso also benefit from high-throughput, low-cost data availability.

Espresso uses HotShot, a BFT consensus protocol that provides finality in a manner that is complementary to Ethereum’s consensus by making a different set of tradeoffs to optimize for speed. Specifically, HotShot is optimistically responsive, meaning it can support Web2 scale under normal networking conditions while sustaining Web3 levels of decentralization.

HotShot is derived from the HotStuff family of consensus protocols, but optimized for the specific needs of layer 2s, namely speed, security, and enabling seamless crosschain interoperability. It reaches finality in under a second. For more on HotShot, check out the academic paper or read this post comparing it to Tendermint. 

Most interoperability solutions today are bandaids over slow base layer finality. They improve crosschain UX but do so by introducing risk and forcing action based on pre-finalized state. But advances in consensus research and cryptography make a better design possible: a base layer fast enough to enable secure, real-time communication between chains without tradeoffs. That's Espresso.

Espresso provides sub-second, BFT-secured finality to any integrated chain or application regardless of their stack, VM, proof system, or sequencing logic. This universal base layer enables all chains to interoperate securely without compromising their sovereignty.

Pre-existing applications that rely on crosschain messaging, such as bridges and intent systems, can plug in to Espresso to improve their latency and security.

Crosschain messages are only as secure as the finality backing them. Espresso enables more secure finality than the confirmations granted by centralized sequencers, without sacrificing speed, and faster finality than bridging through a layer 1 like Ethereum, without sacrificing security.

Crosschain messages based on Espresso's finality thus allow applications that rely on crosschain message passing, such as bridges, to quickly settle bridge transactions without having to rely on single points of failure such as a centralized sequencer, and without having to wait 12 minutes for finality from a layer 1 like Ethereum. 

The Espresso Systems team works closely with other teams developing crosschain messaging protocols, such as Hyperlane and LayerZero, and has spent significant time researching this topic. Learn more about our crosschain communication research here.

Espresso dramatically improves intent-based bridging by enabling solvers to act on secure finality in under a second rather than taking on sequencer or settlement risk. Today, intent-based bridges like Across rely on solvers who escrow funds on the source chain and pay users on the destination chain. Solvers typically risk getting rugged by acting on centralized sequencer confirmations to provide fast UX (rather than waiting for layer 1 settlement), pricing this risk into their fees.

With Espresso's finality, solvers can reliably confirm escrow transactions in under a second using BFT consensus rather than trusting individual sequencers. This reduces solver risk, improves capital efficiency, and enables more competitive pricing for users. Faster, more secure finality also enables more efficient rebalancing for solvers. This is especially helpful for the longer tail of layer 2 applications whose centralized sequencers are deemed less trustworthy.

Espresso ensures that the transaction ordering over which a ZK proof has been generated can’t change. This means that applications verifying a ZK proof know there won't be any conflicting proofs in the future. Without a fast, secure base layer like Espresso, honest provers might generate valid ZK proofs over layer 2 data that never settles as expected due to sequencer equivocation (e.g., a sequencer confirms for a user that their transaction is included in a block, but later excludes that transaction from the block it publishes to layer 1).

Espresso’s finality, as well as a protocol-level restriction preventing a layer 2’s sequencer from equivocating, solves this by ensuring ZK provers always have access to the correct transaction data in under a second.

Whether you're deploying a dedicated environment for a financial application like tokenized assets, payments, or collateral management, building a layer 2, or exploring another use case, get in touch with us here to discuss your specific needs and timeline. You can also check out our documentation or browse use cases relevant to your situation.

Espresso's mainnet is permissionless. You can start running Espresso nodes by following our documentation.

To get the benefits of Espresso as a user, you need to be using a chain or application that integrates with Espresso.

If the app or chain you use doesn't yet use Espresso, let them know by posting about it on X and tagging Espresso. We're always welcoming more chains and applications to our growing ecosystem of projects that believe in a seamless, unified onchain user experience.

Yes. Privacy lives at the application and execution layer, not at Espresso itself. Institutions can encrypt transactions before submission, limit execution to authorized participants, and use proofs that let counterparties verify a transaction's validity without exposing the underlying data (counterparty identity, balances, trade size, or position state). Espresso's role is to finalize these encrypted transaction streams without executing or decrypting them, so sensitive workflow data never needs to become part of any public record, while institutions still get a finalized, verifiable outcome other parties can rely on.

Espresso uses BFT (Byzantine Fault Tolerant) consensus, the same class of fault-tolerant design used in distributed systems where no single party should be able to unilaterally alter an outcome. Security holds as long as fewer than one-third of validators act maliciously or collude; an attacker would need to control over one-third of Espresso's decentralized validator set to compromise finality, a threshold that becomes more expensive to reach as the network grows.

Espresso's validators run HotShot consensus to provide cryptographic finality on block ordering and data. A protocol-level restriction ensures that once Espresso finalizes a block, integrated chains can only publish matching blocks downstream (e.g., to another layer 1 like Ethereum, where a chain may maintain a bridge). In other words, there is no way for a finalized record to be silently altered or contradicted after the fact.

Espresso also runs on proof-of-stake consensus, requiring validators to stake ESP tokens as collateral. This adds economic security on top of BFT consensus: validators have real capital at risk, so compromising finality would require both coordinating collusion across the validator set and forfeiting substantial economic value. This combination of cryptographic and economic guarantees is designed to give institutions a security model comparable to the strongest guarantees in the blockchain ecosystem, without relying on trust in any single operator.