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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Offchain Labs Partnership: Improving Transaction Ordering for Arbitrum Technology Chains & Beyond

Offchain Labs and Espresso Systems are partnering to bring an improved approach to transaction ordering and a decentralized, shared sequencing option to Arbitrum technology chains like Arbitrum One, Arbitrum Nova, & the Arbitrum Orbit ecosystem.

L2s are succeeding in scaling Ethereum, with rollups like Arbitrum running in production for 2+ years and sustaining over $5 billion in total value locked. These infrastructure innovations are transforming users’ experiences and opening new possibilities for developers. They also face outstanding challenges. Users still deal with front-running and harmful forms of MEV; rollups still have some points of centralization; and rollup ecosystems are already starting to fragment.

At Espresso Systems, we are working to tackle the toughest problems facing rollups by developing an open, decentralized transaction sequencing network for any L2 to freely opt into. We envision fully decentralized rollup stacks that protect users from dynamics like front-running, all on a permissionless platform.

Today, we are thrilled to announce a partnership with Offchain Labs to advance and accelerate this vision. Offchain Labs has pioneered the research and development behind many of the most technologically-mature and widely-adopted blockchain scaling solutions, including major contributions to Arbitrum One, Arbitrum Nova, and now the rapidly growing ecosystem of Arbitrum Orbits.

We see Offchain Labs’ collaboration with us as a strong signal that even teams with strong technology affiliations of their own will continue to prioritize permissionless approaches to coordination and technology. We will be working together on the research and implementation of an improved transaction ordering system, and will be partnering to make this, along with the Espresso Sequencer, an option for Arbitrum technology chains and beyond.

The Espresso Sequencer is designed to allow multiple rollups to share a single decentralized platform for fast confirmations of transaction inclusion, while still allowing individual rollups to optionally choose their own transaction ordering policies. Examples of transaction ordering approaches include auctions, first-come first-serve (FCFS), or content-oblivious (threshold encryption). We at Espresso Systems are glad to put resources behind ordering approaches that align with user needs, starting with Timeboost.

A first-come-first-served (FCFS) transaction ordering policy is simple and protects users in many regards. Offchain Labs has recently proposed Timeboost as a way to improve upon the FCFS policy used by their sequencer today by mitigating “latency racing” dynamics. For the last 6 months, Offchain Labs and others have been working across the Arbitrum community to get feedback and iterate on the Timeboost proposal. They have published a technical paper on their progress here. We are now working alongside Offchain Labs on further research around Timeboost. We will be undertaking development of a production-ready, open-sourced, and distributed implementation of Timeboost that can be adopted by any network, including any Arbitrum rollup. This will be integrated directly with the Espresso Sequencer.

In parallel with our work on Timeboost, we are glad to have Offchain Labs’ support as we now prioritize integration with the Arbitrum technology stack. This work comes on the heels of our recent testnets which have featured support for the OP Stack and the Polygon zkEVM stack. In collaboration with Offchain Labs, we are excited to expand our reach and bring our platform to any Arbitrum technology chain that chooses to leverage our decentralized, shared sequencer platform.

We will be sharing a roadmap soon for our research and implementation of the Timeboost builder module and for the integration of the Espresso Sequencer with the Arbitrum technology stack. Follow along with the work @OffchainLabs and @EspressoSys on Twitter and on the Arbitrum Research Forum for more soon.

If you are a rollup or application developer interested in leveraging Timeboost and/or the Espresso Sequencer, you can get in touch with Espresso Systems here.

Launching Espresso Systems’ Cortado Testnet to the Public

Espresso Systems and Caldera co-deploy Vienna, an OP Stack rollup integrated with the third testnet of the Espresso Sequencer. The Cortado Testnet can sequence transactions for this OP Stack rollup as well as the Polygon zkEVM-based rollup integrated in the previous testnet.

Today we are unveiling the first live, public demo of a shared sequencer, supporting not only multiple rollups but multiple different rollup stacks. With this milestone, we are taking the first strides toward the Espresso Sequencer serving as a neutral, open layer that can connect across all L2s, regardless of stack or ecosystem.

With this release, we are excited to launch a public testnet for Espresso Sequencer Testnet 3: Cortado, seamlessly integrating both an OP Stack rollup and Polygon zkEVM rollup for decentralized, shared sequencing.

As a part of this latest public testnet, we have been working with Caldera on the deployment of Vienna, an OP Stack rollup integrated with the Espresso Sequencer for decentralized, shared sequencing. Our collaboration with Caldera is an early demonstration of the ease at which rollup operators will be able to integrate with the Espresso Sequencer. In addition to the core rollup node, Caldera’s infrastructure includes a bridge UI, testnet faucet, and block explorer. You can get started using all of these components at the testnet’s public homepage.

Along with this public release, we’re releasing documentation on how users can interact with Cortado, and sharing next steps for the Espresso Sequencer.

The release also sees a number of improvements to the Espresso Sequencer protocol. With every testnet release, the Espresso Sequencer’s consensus protocol, HotShot, becomes more reliable. Notably, Cortado now supports a catchup mechanism, which allows nodes to come back online after an arbitrary number of views has passed since it last was online.

Supporting shared sequencing with the Polygon zkEVM and OP Stacks

With the OP Stack integration in Cortado, testnet users can submit transactions for both the OP Stack and Polygon zkEVM rollups integrated with the Espresso Sequencer. This means the Espresso Sequencer is now a shared sequencer between two distinct rollup stacks, and users of both stacks can enjoy the fast pre-confirmations the Espresso Sequencer offers.

We’ve created a video demo that showcases a user submitting a transaction through MetaMask, which is then propagated through Espresso Sequencer nodes. The transaction is then included in a block sequenced by HotShot. For the Polygon zkEVM demo, after the transaction is ordered and included in a rollup block, it is sent to Polygon zkEVM nodes and provers. In the OP Stack rollup demo, the transaction is committed to the L1 testnet after the transaction is ordered and included in a rollup block.

If you’d like to try submitting transactions or deploying contracts to either rollup stack on the public Cortado testnet, you can head to our documentation site where we outline the process to get started. You can also build and run your own local devnet of Cortado by following the steps on the op-espresso-integration repo.

Next steps

Over the last two months, we’ve been working with a number of rollup and rollup-as-a-service teams to integrate with the Espresso Sequencer. A number of those collaborations have resulted in demo integrations, and we will soon share those via our community channels.

We also announced a partnership with Offchain Labs to bring decentralized and shared sequencing to Ethereum rollups. Our collaboration will see both teams jointly research and develop Timeboost, a transaction-ordering design proposed by Offchain Labs. Offchain Labs is also supporting us in building integrations between the Arbitrum technology stack, Timeboost, and the Espresso Sequencer.

In our next testnet, we will be integrating verifiable information dispersal (VID) and a peer-to-peer fallback network into HotShot, increasing resilience and robustness. To stay up to date on this progress, you can follow the HotShot repository on GitHub.

We’re excited to make this testnet public, and are looking forward to users interacting with Vienna, the OP Stack rollup co-deployed with Caldera. If you’re interested in integrating with the Espresso Sequencer, please get in touch with us.

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.

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