Espresso helps rollups:
Scale
01
Decentralize
02
Interoperate
03
Espresso is designed to offer rollups a means of achieving credible neutrality, enhanced interoperability, & long-term alignment with Ethereum.
A shared sequencing marketplace and finality gadget connecting layer-2 scaling solutions
Scale without
compromise
Espresso's HotShot finality gadget is optimistically responsive and guarantees fast transaction finality and throughput limited only by network bandwidth.
Perfectly paired
with Ethereum
HotShot scales to tens of thousands of nodes while maintaining strong performance to enable participation of Ethereum’s full validator set.
Interoperability
at its best
Espresso allows proposers to bid for blockspace across multiple rollups, making cross-chain messaging and bridging cheaper, faster, and safer.
Espresso for
L2 Rollups
Accelerate your decentralization roadmap, inherit security from Ethereum, and interoperate more reliably with other rollups—without sacrificing on value accrual or sovereignty.
Participate as L2 Rollup
Espresso for
App Developers
Offer app developers more reliable and neutral infrastructure. No more single points of failure.
Espresso for
End Users
No compromises. High performance, low (and fair) fees, a diversity of applications, and no lock-in.
Monolithic
Today’s rollup teams develop and maintain all components as a singular package - not modular systems that could easily be swapped or upgraded.
Siloed
Rollups operate in their own silos, introducing all the same issues of interoperability that L1s have experienced.
Centralized
From sequencing to execution and proving, today's rollups are all run and maintained by their own teams - sacrificing credible neutrality and monopoly-resistance.
Shared sequencing
Many rollups leverage the benefits of the Espresso Sequencer, creating efficiencies for interoperability & beyond.
Decentralization
A permissionless network of nodes running the Espresso Sequencer offers robust data availability and transaction ordering.
SCALE
HotShot Consensus is optimistically responsive, so rollups don't compromise on high throughput or fast finality.
Easy integration
The Espresso Sequencer is designed to work seamlessly with existing rollup frameworks and other modular systems.
Proposer-Builder Separation
Espresso Sequencer is designed to be compatible with proposer-builder separation, a paradigm that supports mitigation of the harmful effects of MEV.
Agnostic Ordering
Designed to work with any approach to transaction ordering, from First Come First Serve to MEV-optimized.
Cross-Rollup Building
Block builders across multiple rollups only need to coordinate with one proposer, enabling them to guarantee order and outcomes.
Execution and Outcomes
With block builders integrated, users will receive guarantees of transaction inclusion and execution across multiple rollups.
Participate as
L2 Rollup
If you are building a rollup, we want to work with you.
For support in integrating with us, get in touch here.
Participate as Node Operator
If you’d like to help secure Espresso and have experience running node infrastructure, please reach out.
News & Brews
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Article
Scaling Ethereum without Compromise

We’re excited to announce our Series B fundraise led by a16z crypto.

In 2021, we saw the first layer-2 rollups launch on Ethereum, focusing on scaling transaction throughput without sacrificing sovereignty, security, and decentralization. These systems have grown substantially in usage, even overtaking the Ethereum base layer in some key metrics. As this trend continues, our mission is to ensure that the growing number of rollups can continue to unlock new use cases without needing to give up decentralization, composability, and credible neutrality.

Announcing our Series B funding round

To accelerate this mission, we have raised $28 million in our Series B funding round. We’re excited that a16z crypto has led the round, joined by Polygon, Taiko, o1Labs, StarkWare, Offchain Labs, and core contributors and strategic investors from over 30 notable ecosystem projects — spanning rollups, L2 infrastructure, interoperability, and more. We are excited to work closely with these innovative partners, who are equally motivated to ensure that layer-2 protocols remain decentralized and interoperable.

This additional funding will help us continue product development, meaningfully invest in the broader rollup ecosystem, and set the stage for the community to ultimately operate and govern Espresso as a fully decentralized, credibly neutral public good for all L2s, from based rollups to validiums. We’ll be hiring aggressively to build out our team and expand our efforts. If you are a builder wanting to support the dream of a united Ethereum, please get in touch with us.

A marketplace for shared sequencing for all L2s

Espresso is more than just a shared sequencer, consensus protocol, or tool to facilitate interoperability between rollups — Espresso is a marketplace for shared sequencing, where rollups can sell the right to build their blocks to proposers who bid for these rights. Proposers can also bid on multiple rollup blocks to become shared proposers for multiple chains at once, which allows them to facilitate cross-chain activity. Anyone can participate in this marketplace, including L1 proposers and rollup DAO-appointed sequencers. Rollups that don’t want to worry about sequencing can also simply rely on Espresso to handle it for them.

Espresso’s HotShot finality gadget also offers lightning-fast finality on proposed blocks, ensuring that rollups don’t need to compromise on the experiences that their users are accustomed to. This finality is economically backed by both Espresso stakeholders and Ethereum restakers, potentially scaling to the entire Ethereum validator set, and provides assurances to users that their transactions will be finalized on the L1. Overall, we are building Espresso to be a one-stop solution for rollups to increase utility for their users through improved safety, liveness, and interoperability, while being compensated for the value they create and maintaining their sovereignty and autonomy.

This is an exhilarating time to build and innovate on Ethereum. We remain committed to Ethereum’s rollup-centric roadmap, and are more enthusiastic than ever about its ability to bring real users on-chain. We’re so grateful for the support we’ve received from our investors, partners, and the broader community. Onwards!

Article
Espresso Systems partners with Across to bring fast, secure bridging to Ethereum rollups

We’re thrilled to announce that we’ve partnered with Across to bring faster and more secure bridging to Ethereum rollups and L2s using the Espresso platform. Across is an intents-based interoperability protocol that leverages cross-chain intents to create a better bridging user experience. This partnership will see the Across Protocol leverage Espresso’s fast pre-confirmations secured by the HotShot consensus protocol, which reaches finality after two consecutive blocks. The integration will utilize the shared security and fast finality of HotShot for bridging between rollups.

We recently deployed a version of the Across Protocol on top of the Espresso platform’s Gibraltar testnet. During Beyond the Base Layer at ETHDenver, Espresso Systems CEO, Ben Fisch, demonstrated this integration with a bridge transaction between two Arbitrum Nova chains. The origin Espresso rollup received a pre-confirmation from HotShot within 2 seconds. The transaction was filled on the destination Espresso rollup in another 7 seconds. Overall, this demo highlighted the possibility of bridging between rollups in under 10 seconds, with strong safety guarantees for Across relayers.

Across is a bridging protocol that settles cross-chain user intents through its industry-leading bridge design to provide a superior user experience. Their model outsources equivocation risk to relayers, who opt-in to fill user transactions as fast as possible to earn fees from bridge transactions. To ensure that users do not have to wait for the transaction to finalize on the Ethereum L1, relayers take on the equivocation risk of the source chain.

By utilizing the pre-confirmations from Espresso’s HotShot consensus, Across relayers can fill users’ bridge transactions in seconds. In the event that both rollups involved in a bridging transaction share HotShot as a finality gadget, the relayer avoids risk entirely, as any equivocation would result in them being refunded. This can lead to more competition amongst relayers, which in turn will provide an even better experience and lower fees to the end user.

Espresso is able to provide a fast, secure pre-confirmation through the HotShot finality gadget. HotShot is an optimistically responsive consensus protocol, which means that it can product blocks as quickly as the network allows and reaches finality after two consecutive blocks. HotShot is a proof-of-stake protocol with economic security guarantees (slashing), similar to Ethereum. Moreover, Ethereum validators can contribute security to HotShot through restaking. HotShot can scale up to thousands of nodes, and is designed with the intention of reaching Ethereum-equivalent security.

We are building Espresso to create a platform for shared sequencing, pre-confirmations, and data availability, enabling L2s (rollups, based rollups, validiums, etc) to opt-in to the best sequencing and data-availability design for their use case. If you’re building a rollup, and want to support better bridging protocols for your users, or integrate with a marketplace of shared sequencers offering pre-confirmations for a richer set of user intents, we would love to hear from you. Head to our website at www.espressosys.com and get in touch via the “Participate” link.

About Across Protocol

Across Protocol an intents-based interoperability protocol, capable of filling and settling cross-chain intents. It includes the Across Bridge, for end-users, Across+ for chain abstraction and Across settlement for all cross-chain intent orderflow. Across leverages a competitive ecosystem of third party relayers, who fill orders almost instantly. As the multichain economy continues to evolve, intents-based settlement is the key to solving interoperability and Across is at the core of its execution.

About Espresso Systems

Espresso Systems are the developers of Ethereum’s marketplace for shared sequencing, supporting a wide range of Ethereum rollups and L2s. Espresso Systems has raised over $30mm from backers like Electric Capital, Greylock Partners, Sequoia Capital, and Polychain Capital.

Article
Node operator open application begins for Espresso Sequencer Cappuccino testnet

As the Espresso Sequencer edges closer to a production launch, we are looking to onboard more node operators to support our journey towards building a fully permissionless, credibly neutral interoperability layer for rollups.

The Espresso Sequencer runs on HotShot, a consensus protocol designed specifically to prioritize the high throughput and fast pre-confirmations that users have come to expect from rollups. The Espresso Sequencer also targets Ethereum-level security by scaling to thousands of nodes, while also enabling Ethereum validators to participate in securing the Espresso Sequencer network through Ethereum restaking.

Further decentralizing the Espresso Sequencer

Our current and fourth testnet, Gibraltar, is the first shared sequencer network run with external node operators. We have partnered with Blockdaemon, an industry leading public infrastructure company, to run four Espresso Sequencer nodes across North America, Asia, and Europe. This testnet release also sees the Espresso Sequencer support four rollup stacks (Arbitrum, Cartesi, Optimism and Polygon zkEVM) and several collaborations with rollup projects (see our ecosystem map). You can learn more about the Gibraltar release here.

In our upcoming fifth testnet, Cappuccino, we are looking to further decentralize the sequencer by onboarding more entities to run Espresso Sequencer nodes. We are excited to invite node operators to apply to run sequencer nodes on Cappuccino, which is scheduled for release in late Q1 2024.

Cappuccino will enable us to continue developing a seamless node onboarding process. As part of these efforts, we will provide basic metrics such as peer count, synchronization speed, stats on finalized blocks (time, number of transactions, size, etc.) as well as more advanced metrics that will be required for node operators participating in the Espresso Sequencer’s operation.

Cappuccino will implement other roadmap milestones such as fee payments, key management tooling, and verifiable information dispersal, which uses erasure coding to allow nodes to vote on a block without needing to download the whole block.

If you are interested in running an Espresso Sequencer for the Cappucinno testnet, please consider applying here.

Node operator expectations and specifications

We expect Cappuccino to run with approximately 100 nodes that are geographically dispersed, spanning several cloud and bare metal environments. We are looking to partner with organizations who will run nodes during our testnet, provide user feedback, and help us refine node specifications and onboarding for future releases.

Node operators will be expected to set up and run the testnet and provide occasional DevOps support during the Cappuccino testnet deployment. To support the onboarding process, selected node operators will be provided with technical documentation, an onboarding guide, and a metrics API. Espresso Systems will support node operators by providing documentation, a shared Slack channel, and incident response via on-call procedures.

Node technical specifications

The Espresso Sequencer supports a basic module for nodes participating in consensus and data availability (DA). There are additional, optional modules to run an HTTP server that comes with healthcheck and version endpoints, a query service for history, filesystem and SQL storage, submitting a transaction for sequencing, and checking status.

It is also possible to run a DA node. DA nodes will need to store a certain number of blocks at a time on-demand until an archival node can obtain the DA data, with rough guidelines on storage in the below specifications. Non-DA nodes have no need to persist block data and therefore have negligible storage requirements.

Hardware requirements are still in flux as we refine our testnets and add new features, but for now we recommend the following:

  • RAM: 16–32 GB.
  • CPU: 2–4 cores.
  • Storage (DA node): 20 GB minimum, ability to scale to 3 TB on demand.
  • Storage (non-DA node): Negligible, 10s-100s of bytes.

The detailed expected technical specifications for the Cappuccino testnet are available here.

Timeline

We are opening up the application process for node operators for two weeks, from February 2 until February 16, 2024. We’ll aim to announce selected node operators by the middle of March 2024.

To show prospective node partners what it’s like running an Espresso Sequencer node, we’ll be hosting an AMA with the Blockdaemon team in our Discord on February 6, 2024 at 11 AM EST. We’ll outline the experience of onboarding as a node operator partner, the support model Espresso Systems provides, and what you can expect if you are selected to run an Espresso Sequencer node. If you’re interested in running an Espresso Sequencer node, please consider attending.

We’re looking forward to hearing from those interested in running an Espresso Sequencer node! Please note that although we will not be able to respond to all applicants individually, we will share progress updates and selection decisions in our Discord via the #node-operators-updates channel.

The node operator questionnaire for the Cappuccino testnet is available here.

Article
Gibraltar Testnet Sees External Operators Running Espresso Sequencer Nodes

Espresso Systems releases testnet 4 (Gibraltar), showcasing an integration with the Arbitrum technology stack

Today, we are unveiling the fourth testnet of the Espresso Sequencer, Gibraltar. This testnet showcases a new integration with the Arbitrum technology stack and sees external operators running Espresso Sequencer nodes for the first time.

We’re excited to be supporting the Arbitrum ecosystem with a shared sequencer option that will provide Arbitrum technology chains with improved interoperability and decentralization, while maintaining the lightning-fast experience their users are accustomed to.

The Espresso Sequencer is a credibly neutral, fast-finality layer that any rollup can leverage for transaction ordering, data availability, and fast pre-confirmations. The sequencer protocol leverages HotShot consensus, enabling it to scale to thousands of nodes while still providing near-instantaneous pre-confirmations.

For this testnet release, we’ve been working closely with the Blockdaemon team who is managing external sequencer nodes for Gibraltar. We are thrilled to see Gibraltar become the first shared sequencer network running with external node operators.

This release is available to the public. The code we have developed to integrate with the Arbitrum tech stack is available on GitHub. As a part of this release, we have also published documentation that will enable developers and users alike to interact with Gibraltar and its integrated rollups.

If you are building a rollup, you can get started on your integration with the latest Espresso testnet here and reach out to collaborate with us here.

Gibraltar running on external node operators

We have partnered with Blockdaemon, a blockchain infrastructure provider, who is supporting us by deploying external sequencer nodes. They will be managing 4 sequencer nodes that are based in Europe and Asia. This collaboration sees the Espresso Sequencer make progress in decentralizing the network, and become more resilient and geographically distributed.

We’ll be hosting an AMA with the Blockdaemon team in our Discord on February 6, 2024 at 11 AM EST to share our progress in onboarding external node operators the Espresso Sequencer network. We’ll also hear from the Blockdaemon team about their experience as an Espresso Sequencer node operator. If you’re interested in running an Espresso Sequencer node, you’ll definitely want to attend.

Integration with Arbitrum stack

In September, we announced a partnership with Offchain Labs to explore decentralized, shared sequencing for Arbitrum technology chains. As a part of the Gibraltar testnet, we’re unveiling a new integration between the Espresso Sequencer and the Arbitrum technology stack.

Arbitrum technology chains will now have access to fast, decentralized shared sequencing. Arbitrum Orbit chains can integrate with the Espresso Sequencer today, and see how its preconfirmations are comparable to those of a centralized sequencer.

The integration of the Espresso Sequencer into the Arbitrum tech stack follows the announcement of our co-authored roadmap for decentralized Timeboost, a modified first-come-first-serve transaction ordering policy.

As we work with Offchain Labs on R&D efforts related to decentralized Timeboost, we are also exploring how the Espresso Sequencer can best serve as a neutral fast finality and interoperability layer for Arbitrum Orbit chains and the Arbitrum ecosystem. Another benefit of this integration is that it also gives the Espresso Systems and Offchain Labs teams an environment where we deploy decentralized Timeboost for testing.

Arbitrum Orbit chains can deploy their rollups on the Gibraltar testnet today by following the steps in our integration guide.

Caldera deploys Arbitrum rollup, Milan, integrated with Espresso Sequencer

Users and developers can submit transactions to the Milan rollup co-deployed with Caldera today. The Milan rollup is live and processing transactions, and users can easily interact with the rollup through their MetaMask wallet.

Developers can also deploy contracts to the Milan rollup by following the instructions listed in Caldera’s documentation.

AltLayer’s Arbitrum rollup, Kyoto, coming soon

AltLayer will also be releasing an Arbitrum rollup, called Kyoto, deployed on the Espresso Sequencer as a part of this public release. We will release more details on Kyoto when it is live and in production.

We’re excited to be working with the Caldera and AltLayer teams on deploying multiple rollups to the Espresso Sequencer!

Supporting shared sequencing for the Polygon zkEVM stack, OP Stack, Cartesi Stack, and Arbitrum technology chains

With the Arbitrum stack integration in Gibraltar, users can now submit transactions for rollups built on the Polygon zkEVM stack, Cartesi Stack, OP Stack, and Arbitrum technology chains. This now means that users of any rollup technology stack can enjoy the fast pre-confirmations the Espresso Sequencer enables.

If you’d like to try submitting transactions or deploying contracts to any of the integrated stacks on the Gibraltar testnet, you can head to our documentation site where we outline how you can get started. You may also build and run a local devnet of Gibraltar by following instructions in our GitHub.

Join the Espresso Ecosystem

The Gibraltar release follows our Cortado (testnet 3) release in September, 2023. Cortado was the first publicly available shared sequencer testnet, integrating with both the Polygon zkEVM and OP Stacks. Now, with the Arbitrum stack integration, we continue to support various rollup stacks and showcase how the Espresso Sequencer can provide credibly neutral, decentralized, shared sequencing for any number of rollups.

Be sure to follow along on Twitter/X and at our website for further updates on Gibraltar and our collaboration with Offchain Labs.

If you’re interested in deploying on the Gibraltar testnet, please get in touch with us here.

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