Espresso helps rollups:
The Espresso Sequencer is designed to offer rollups a means of achieving credible neutrality, enhanced interoperability, & long-term alignment with Ethereum.
A decentralized sequencer and data availability system connecting layer-2 scaling solutions
Scale without
The Espresso Sequencer’s optimistic responsiveness guarantees fast transaction finality and throughput limited only by network bandwidth.
Perfectly paired
with Ethereum
HotShot, our consensus protocol, scales to tens of thousands of nodes while maintaining strong performance to enable participation of Ethereum’s full validator set.
at its best
The Espresso Sequencer, shared across multiple rollups, makes cross-chain messaging and bridging cheaper, faster, and safer.
Espresso sequencer for
L2 Rollups
Accelerate your decentralization roadmap, inherit security from Ethereum, and interoperate more reliably with other rollups.
Participate as L2 Rollup
Espresso sequencer for
App Developers
Offer app developers more reliable and neutral infrastructure. No more single points of failure.
Espresso sequencer for
End Users
No compromises. High performance, low (and fair) fees, a diversity of applications, and no lock-in.
Today’s rollup teams develop and maintain all components as a singular package - not modular systems that could easily be swapped or upgraded.
Rollups operate in their own silos, introducing all the same issues of interoperability that L1s have experienced.
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.
A permissionless network of nodes running the Espresso Sequencer offers robust data availability and transaction ordering.
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 the Espresso Sequencer and have experience running node infrastructure, please reach out.
News & Brews
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Blockworks: Offchain Labs, Espresso Systems link up on transaction ordering tech

Offchain Labs and Espresso Systems will integrate both Timeboost and decentralized sequencer technology with the Arbitrum technology stack

Ethereum scaling solution Offchain Labs is partnering with blockchain infrastructure company Espresso Systems to bring Timeboost — a transaction ordering technology — to life.

The teams will also work on integrating both Timeboost and the Espresso Sequencer with the Arbitrum technology stack.

The Espresso Sequencer is a decentralized sequencing layer that layer-2s can choose to opt into, Ben Fisch co-founder and CEO of Espresso Systems told Blockworks.

“Having Offchain Labs’ support of this vision is a strong signal to us and to the Ethereum community that even teams with strong technology affiliations of their own will continue to prioritize permissionless approaches to coordination and technology,” Fisch said.

Offchain Labs & Espresso Systems: Transaction Ordering Technology to Ethereum Rollups

TLDR: We’re partnering with Espresso Systems to bring decentralized and open shared sequencing technology across Ethereum rollups — improving safety, security, and the user experience across networks. Our team is contributing key research and resources towards our previously proposed transaction-ordering policy, Timeboost, and opening the doors to allow any network — including any Arbitrum chain — to adopt Timeboost and integrate directly with the Espresso Sequencer.


Today, we’re excited to announce that we’ve partnered with Espresso Systems to bring decentralized and open shared sequencing technology to Ethereum rollups. Our teams will undertake joint research and development of Timeboost — a transaction-ordering design we proposed earlier this year — and will also support technical integrations between the Arbitrum technology stack, Timeboost ordering, and the Espresso Sequencer.

Our teams have a shared vision for a decentralized and user-aligned future of shared transaction sequencing on Ethereum rollups. To achieve this vision, we’re supporting Espresso Systems in building a production-ready, open-sourced, and distributed implementation of Timeboost that can be integrated into the Espresso Sequencer. Support for the Arbitrum tech stack will enable any Arbitrum chains to integrate with the Espresso Sequencer and further the implementation of a neutral and open protocol that is compatible with all of Ethereum’s rollups.

Cortado Testnet Integrates with OP Stack

Espresso Systems releases testnet 3 (Cortado), enabling OP Stack developers access to the Espresso decentralized shared sequencing network.

Today we are releasing our third testnet of the Espresso Sequencer, Cortado, which includes an integration with the OP Stack. We are glad to support the Optimism ecosystem through offering OP Stack developers a means to not only decentralize transaction sequencing but also share sequencing with other rollups for enhanced interoperability. The Espresso Sequencer is a network that will be shared across many rollups in multiple ecosystems to enhance interoperability by making bridging and atomic transactions more efficient and more secure for users. Underneath the hood, it is a consensus protocol with fast finality, high throughput, and the ability to scale to thousands of nodes.

Any rollup can leverage the Espresso Sequencer for transaction ordering and (optionally) data availability, replacing dependance on centralized sequencers. The Espresso Sequencer is designed to offer rollups a means of achieving more credible neutrality, more secure and efficient interoperability, mitigation of harmful MEV, and long-term economic incentive alignment with L1 validators.

The OP Stack is the standardized, shared, and open source development stack that is maintained by the Optimism Collective. It underpins OP Chains including Base, Zora, PGN, with new OP Chains committing to the vision regularly. These early chains, along with OP Mainnet, are already scaling on-chain activity. In the last month, the four OP Chains combined to use 4.6m gas per second, about 3.7x of the gas used on L1 Ethereum in the same period.

The code we have developed to integrate with the OP Stack is open source and available here and documentation, including architecture, can be found here. You can spin up and experiment with a local version of Cortado testnet and the OP Stack integration by following the instructions here.

Optimism Foundation Mission: Leader Election Proof of Concept

Last June, we undertook work on an Optimism Foundation Mission (RFP) calling for development of a Leader Election Proof of Concept. This work is designed as an open, public contribution to support the Optimism Collective’s progress toward technical decentralization. We at Espresso Systems are glad to have the opportunity to work closely with engineering leaders in the Optimism ecosystem and are proud to be able to contribute to this mission. You can find the code specifically related to this work here, documentation here, and our past updates to the community here.

“The integration of Cortado is an exciting milestone for the OP Stack. Not only does it lay the groundwork for additional sequencing protocols for OP Chains, it also underscores the Espresso team’s commitment to open-source values and community contribution.” said Ben Jones of the Optimism Foundation. “This milestone represents a step towards a standard that benefits developers, projects, and the Optimism Collective on the whole.”

Public Deployment with Caldera

In the coming weeks, we will be continuing our work with Caldera to deploy a publicly hosted testnet, including an OP Stack rollup. On this test rollup, users and developers will be able to deploy test contracts, submit transactions, and interact with applications in a real-time testing environment where all rollup transactions are sequenced by the Espresso Sequencer. Through familiar interfaces like MetaMask, users will be able to submit transactions and experience the rapid pre-confirmations provided by the Espresso Sequencer.

Caldera is a leading rollup-as-a-service company that enables developers to launch customized rollups with one click, leaving it up to the developer to choose what data availability, sequencer, and other layers underpin the system. Caldera supports rollups including Manta, Loot Chain, Syndr, and others.

Matt Katz, CEO of Caldera, said: “We’re incredibly excited to work with Espresso to bring decentralized sequencing to the OP Stack. Rollups today are centrally sequenced—meaning they do not yet fully live up to the decentralization ideals that crypto users will come to expect. We’re looking forward to collaborating further with Espresso, and offering decentralized sequencing to our users.”

Join The Espresso Ecosystem

With this release, we are also glad to welcome rollups and applications including Airchains, Kinto, Opside, Cartesi, Omni, and Vistara to the Espresso ecosystem. We are working with all of these teams to support research and integration of the Espresso Sequencer. There are currently a dozen different rollup teams working on their own bespoke integrations. If you are building a rollup or developing an application on a rollup and think you could benefit from the Espresso Sequencer, please reach out here.

Our work on Cortado follows on from our Doppio (Testnet 2) release in July. Doppio achieved competitive throughput benchmarks that showcased 1000 nodes (with a committee size of 10) achieving 29.41 MB/s which is approximately 100–200k ERC-20 transfers per second. Doppio also enabled users to experience fast pre-confirmations as the Espresso Sequencer sequenced their transactions. For that release, we featured an integration with the Polygon zkEVM stack. Now, with the OP Stack integration, the Espresso Sequencer is taking its first steps toward shared sequencing, with the platform being shared by multiple rollups—and multiple rollup stacks.

Be sure to follow along on Twitter and at our website for further updates on Cortado, including our upcoming public network release.

Blockworks: Blockchain scaler to offer third testnet integration

Shared sequencers are an essential part of decentralization that may eventually lead to mass adoption

Blockchain scaling and privacy infrastructure company Espresso Systems will release its third testnet of the Espresso Sequencer for OP stack builders.

The testnet, named Cortado, will include work for an Optimism Request for Proposal (OP RFP) that aims to decentralize sequencers.

Rollup solutions today run their own sequencers that have their own execution environments. These sequencers are responsible for ordering transaction information that is then sent to a virtual machine.

To ensure there is no single authority that orders these transactions, projects such as Espresso Systems are exploring ways to diversify these sequencers.

The initial release will be a locally hosted demo version of an OP stack rollup running on Espresso that enterprises can test.

Over the coming weeks, a publicly hosted canonical OP stack testnet will be released. This testnet will be similar to the testnet Doppio, which went live in July, according to Jill Gunter, chief strategy officer at Espresso Systems.

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