With the advent of any new technology, it is difficult to imagine what kinds of applications it could enable. AI continues to globally captivate businesses, developers, and consumers in every category. While AI continues to find its place in every aspect of life, there are two areas it hasn’t quite found its stride: crypto and consumer.

Through Onchain Labs, we’re committed to fostering innovation in blockchain applications. Today, we’re excited to announce our collaboration with a team that continues to impress:

Simcluster

@Simcluster is a parallel digital society at the intersection of AI, crypto, gaming, and social media, created specifically to embrace the era of AI slop. Widespread access to AI models has triggered a surge of slop across social media feeds. It’s easy to see that it will be difficult to discern slop from reality very soon. Webster selected “slop” as the 2025 word of the year, further cementing this phenomenon into culture.

Simcluster takes a maximalist position on slop — instead of fighting it, they believe that “the only way out is through.” The app offers a gamified social experience where the goal is simple: create engaging AI-generated content to climb the leaderboard and earn clout. Simcluster utilizes its own in-app content studio to enable users to seamlessly create and edit text, images, video, and music. The scope of studio output will expand dramatically as AI continues to evolve, where Simcluster will be a dedicated tool for the creation of new worlds, programs, games, and agents.

Simcluster utilizes a “hyperprompting” system, enabling users to efficiently mold model outputs without prior prompting experience. Hyperprompting is to prompting as vibecoding is to programming. It lets users create masterpieces without requiring Altman-levels of prompting experience.

Sound easy? There’s a catch.

Simcluster limits content to the output of its concept system.

Simcluster is built on three fundamental components: concepts, content, and clout. Users can create concepts out of anything. These concepts are composable building blocks that enable users to create content. Concepts can best be compared to LLM prompts. All info within a concept’s definition will be directly used to generate content. Whenever a concept is used, the creator of that concept earns virtual currency, known as clout. Clout is both an in-game currency and social credit engine that inspires users, known colloquially as “simulants,” to keep playing, or “clusting.”

To create concepts or content, users must spend clout. The more clout a user has, the higher they are on the leaderboard. The higher a user is on the leaderboard, the easier it is to earn more clout. Users also earn clout anytime somebody engages with their content. Clout is not a tradable asset, has zero monetary value, and exists solely for *pun intended* social clout.

These gamified mechanics create an engaging virtual world for players to participate in, where a variety of play styles can be used depending on their preference. Concepts serve as an innovative spin on tokenized IP, especially when considering how they are key inputs into content.

We’ve chosen to collaborate with Simcluster to embrace an emerging app in consumer AI. Blockchain games and consumer crypto apps often fail because they over index on speculation. We’ve seen that speculation as a product often loses its fun after all the value leaves, as evidenced by previously popular crypto apps left for dead.

Harvey (@npceo_) and the team have an unrelenting curiosity and drive to create an entertaining, dystopian digital world that keeps users returning for more. Crucially, Simcluster is very different from prior crypto gaming or social ventures, which often suffer from cold start problems due to requiring users to have risk tolerance from day one. Simcluster keeps it simple — play the game, climb the leaderboard, have fun.

It’s important to note that Simcluster has no blockchain elements live today. Although clout is a non-transferrable, free-to-earn virtual currency, we’ve seen that some of the most successful gaming companies in web2 often employ a two-tiered in-game currency model. Simcluster plans to bring its composable concept registry and creator reward system onto Arbitrum. We’re excited to watch the platform grow from an emerging gamified social platform to something much bigger.

For the curious, use our referral code ARBITRUM to jump to the front of the line and start using Simcluster today.

Through Onchain Labs, our team will be involved in advisory capacity, assisting with GTM, partnerships, and protocol design. If you’re a hungry founder building something novel in crypto, apply for Onchain Labs here: https://forms.gle/QTWcbZWFYUaoknqN7.

*Disclosure*

Onchain Labs is a collaboration between The Arbitrum Foundation and Offchain Labs, either of which may have a financial interest in Simcluster through investments and/or other commercial arrangements.

Welcome to Arbitrum, Simcluster was originally published in Offchain Labs on Medium, where people are continuing the conversation by highlighting and responding to this story.

Arbitrum’s New Architecture

Ethereum has long faced scalability challenges that have hindered its ability to handle the ever-growing demand for decentralized applications. As the leading and most secure smart contract platform, Ethereum’s main bottleneck has always been its ability to process transactions quickly and at a low cost without compromising on its inherent security. To address these limitations, various L2 solutions have emerged, with Arbitrum standing out as the most successful and widely adopted rollup in the Ethereum ecosystem.

Arbitrum, having been a pioneer in scaling Ethereum with optimistic rollups, is now advancing its exploration of Zero Knowledge (ZK). This multi-prover approach sets Arbitrum chains apart from single-prover rollups, offering flexibility and ensuring the ecosystem isn’t tied down by one proof system but can also evolve as ZK tech matures.

Arbitrum chains will be able to tap into this technology in early next year with a DAO proposal to discuss the potential integration into Arbitrum One expected in 2026. The introduction of ZK can help create an even more customizable stack, giving developers even more opportunities to create chains that precisely address their scaling needs.

The incorporation of multi-prover technology introduces a unique model that can strengthen Arbitrum’s scalability and furthers trust-minimized solutions. ZK, in combination with fraud proofs and trusted execution elements (TEEs), reduces the vulnerabilities typically associated with single-prover solutions. This new approach can allow Arbitrum to strengthen each technology, creating a more secure and resilient ecosystem. This added protection can benefit high-value chains that handle sensitive or critical transactions, giving users and developers more confidence in their applications.

Multi-Proving as Flexibility

While ZK technology will be a powerful addition to Arbitrum’s infrastructure, it doesn’t replace the existing optimistic rollups model. Instead, it works in tandem with it to offer a multi-prover approach that allows for greater flexibility and adaptability. This intended solution combines the strengths of both technologies, offering developers a wider range of configurations to optimize their chains based on their unique needs.

The flexibility inherent in this multi-proving architecture, if adopted, means that Arbitrum can support a broader array of use cases, from gaming and high-throughput consumer applications to enterprise-level privacy solutions. By giving developers the option to choose from a diverse set of security configurations, Arbitrum can enable applications to be both scalable and secure, without being tied to a single technology stack. This approach can help Arbitrum remain a versatile and future-proof platform as decentralized applications continue to evolve.

If Arbitrum integrates ZK, it is likely to reduce settlement times, unlocking new levels of efficiency and improving the user experience. Faster settlement and reduced costs, enabled by the hybrid use of fraud proofs, ZK and TEEs, mean that applications on Arbitrum can operate at scale without the traditional overhead associated with other L2 solutions. This integration can help push up effective gas limits — contributing to overall throughput goals of 1 Gigagas per second and 100ms block times, further solidifying Arbitrum’s capability to handle large-scale applications across industries.

In addition to scalability and speed, privacy is another significant area where Arbitrum’s approach excels. With optional privacy through ZK technology, Arbitrum apps and chains will have more ways to offer enterprise-level confidentiality while maintaining full auditability. This is especially important for industries like finance, where privacy isn’t just desirable, it’s a regulatory requirement. Arbitrum’s AnyTrust technology allows businesses to balance privacy needs with compliance, supporting applications in meeting industry-specific regulatory standards without compromising on security.

Future of Ethereum and Arbitrum

The future of Ethereum and Arbitrum looks promising as both continue to evolve and adapt to the changing needs of decentralized applications. Arbitrum’s multi-prover approach, which combines the strengths of optimistic rollups and ZK technology, will offer developers the flexibility to scale their applications while maintaining high levels of security. With the ability for Arbitrum stack chains to upgrade and configure their security models at will, Arbitrum provides an adaptable and developer-driven platform ready to support the next generation of decentralized applications.

As Ethereum grows and matures, Arbitrum has positioned itself as a key player in the ongoing evolution of scalable and secure blockchain infrastructure. With its customizable approach, Arbitrum is paving the way for a future where enterprises, institutions and developers can build high-performance applications while maintaining the trust, privacy and security that blockchain technology requires.

Want a chain that plays by your rules? Learn more about launching on Arbitrum here.

Scaling Ethereum with ZK and the Road Ahead for Arbitrum was originally published in Offchain Labs on Medium, where people are continuing the conversation by highlighting and responding to this story.

In collaboration with The Arbitrum Foundation, we are excited to announce Onchain Labs, a new program aimed at accelerating innovative onchain experiences on Arbitrum.

Offchain Labs (OCL) revolutionized Ethereum in 2021 by launching Arbitrum One, one of the first optimistic rollups. Since then, we’ve consistently pushed innovation boundaries—launching an AnyTrust chain, creating Orbit for permissionless chain deployment, enabling development in familiar languages like Rust, strategically acquiring Prysm in 2022 to advance the Ethereum ecosystem, and growing the Tandem partner studio and venture capital arm.

Our ongoing work focuses on scaling throughput with an alternative client, enhancing Arbitrum with ZK integration, and improving the Ethereum experience through our Universal Intents Engine. These contributions have positioned Arbitrum as one of the most performant ecosystems in the space — and we’re just getting started.

As others play catch up, we now have a unique opportunity to empower the Arbitrum application layer.

As original builders of the chain and active users of Arbitrum applications, we have both a deep technical understanding of how to fully harness Arbitrum’s technology and crucial insights into what users truly want. We’ve generated plenty of ideas for game-changing apps — similar to how we continue to push boundaries on the infra level — but recognize we can’t build all of these ourselves. Through Onchain Labs, we’re dedicating resources to support developers looking to rapidly expand the application layer by ideating with them from the ground floor to bring the best user experiences to Arbitrum. As we do with many Arbitrum teams, we’ll provide certain product, IT, and GTM support to these early-stage projects, collaborating closely to help their applications thrive on Arbitrum.

Arbitrum boasts both the best technology and the best talent. With Offchain Labs’ support, we’re confident we’ll see industry-leading applications that are uniquely possible on Arbitrum. We’re excited to roll up our sleeves and work alongside the community to make this happen.

But building infrastructure and applications is only one part of the puzzle. Alignment is equally important. We’ve seen how extractive ecosystems create zero-sum games, where only a few profit at the expense of others. This stands in stark contrast to the core ethos of crypto.

As an industry, we can — and must — do better.

Onchain Labs will only support projects that commit to fair and equitable launches. This is essential for fostering community alignment. There’s no reason why all participants in an ecosystem can’t succeed together.

Projects supported by Onchain Labs will be experimental and volatile. We encourage all participants to do their own research (DYOR) before purchasing any tokens affiliated with Onchain Labs projects or interacting with them. Our role will be focused strictly on product and go-to-market advice. Tandem may or may not purchase associated tokens in public markets.

The first Onchain Labs project will soon emerge from stealth. If you’re a talented team interested in receiving Onchain Labs’ support, fill out this form, and we’ll be in touch.

See you in the trenches 🫡

Onchain Labs — Accelerating the App Layer of Arbitrum was originally published in Offchain Labs on Medium, where people are continuing the conversation by highlighting and responding to this story.

Authors: @0x_allan (Allan), @0xgodzillaba (Henry), @yahgwai (Chris)

The rollup ecosystem is expanding at a remarkable rate and coalescing around Ethereum for its security and data availability properties. However, most of these Layer 2 or Layer 3 chains have their own state and finality guarantees. While this multi-chain world enables faster and cheaper transactions, it also introduces fragmentation. As a result, users and applications rely on Crosschain communication that is not always secure, standard, or seamless.

In this blog post, our team introduces the Crosschain Broadcaster Standard — a smart contract system that aims to solve a piece of this puzzle. This standard is built on the idea that all data needed to prove a particular message is already onchain somewhere, accessible via storage proofs. For context, a storage proof is a cryptographic proof that a certain piece of data really does exist in a given blockchain’s state at a specific block. Broadcaster enables rollups that share a common ancestor–like Ethereum–to authenticate messages on each other’s chains without additional trust assumptions.

In this blog post, we’ll explore what the Crosschain Broadcaster Standard is, what problems it solves, and how it works, including:

• Why Crosschain messaging is difficult and why the ecosystem needs a standardized solution
• The major components of the Crosschain Broadcaster Standard: Broadcaster, Receiver, BlockHashProver, and Pointers
• An example of a burn-and-mint token bridge built on top of the Crosschain Broadcaster Standard
• A high-level look at how messages flow through the system

Let’s jump in!

Why Crosschain Messaging Matters

Imagine an application that’s deployed on multiple chains, like Arbitrum One and Base. A user wants to take some action on Arbitrum One that triggers a response on Base. Maybe a user wants to prove they locked some collateral on Arbitrum One to borrow something on Base. Today, crosschain actions like these often rely on third party bridging solutions that introduce several issues, such as:

1. Trust: Many existing crosschain solutions rely on a small set of centralized parties (ex. validators, oracles, relayers) to confirm that data from one chain is valid on another. Trusting those parties to do the right thing with your message or your funds is a prerequisite for users.
2. Complexity: Different rollups have different ways of achieving and recording finality. Consequently, Crosschain developers must create custom integrations with each chain to access finality data and stitch it together with other, dissimilar chains.
3. Maintenance: Rollups undergo upgrades. During these upgrades, chain owners may change finality conditions or update storage mechanisms. A Crosschain application that worked previously may break if the rollup changes where finality outcomes can be found.

The Crosschain Broadcaster seeks to solve this by providing a trustless, flexible messaging standard that is rollup agnostic. Rather than trusting offchain actors, Broadcaster utilizes onchain storage proofs for rollups rooted in Ethereum. As a smart contract standard, Broadcaster can provide standardized interfaces for messaging across any EVM-compatible chain. It is also upgradeable by design, anticipating rollup evolution while providing immutable endpoints for continuous integration. No trust assumptions, no complex customizations, no core protocol requirements.

How Crosschain Broadcaster Works

The Crosschain Broadcaster standard builds on the idea that all data needed to prove a particular message is already onchain somewhere. If a chain can figure out the correct block hash information for another chain, it can verify the existence of any piece of data in that chain’s state. Put another way, if the block hash of a given chain is final, then so is the existence of any messages stored at or before that block.

Let’s walk through a simple scenario:

1. A user on Arbitrum One submits a message to the Broadcaster contract on Arbitrum One.
2. The Broadcaster contract stores that message in a unique slot on Arbitrum One.
3. On Base, someone wants to confirm that message indeed exists on Arbitrum One; they call the Receiver contract on Base and provide:

• a “route” of Pointer addresses that leads from Base (L2) to Ethereum (L1) to Arbitrum One (L2)
• the necessary storage proofs for verification

4. The Receiver on Base works through each Pointer/Prover in the route, eventually obtaining Arbitrum’s block hash and reading the Broadcaster’s storage.

5. If the message is found, the Receiver returns success plus a timestamp. This result can trigger an arbitrary action in a smart contract that is subscribed to the Receiver

Now let’s go through a practical example: intents-based bridging. Intents-based bridging–like Across–allows users to move assets faster than they can through canonical bridges. Today, many intents-based bridges do this in four main steps:

1. User deposits funds into an Escrow contract on Base
2. A solver sends funds to the user through a Fulfillment contract on Arbitrum One
3. The Fulfillment contract sends a message to the Escrow contract saying “solver X sent Y tokens to user Z at time T”
4. The Escrow contract receives and validates the message from the Fulfillment contract, releasing the user’s funds to the solver on Base

In this example, a message is sent and received in Step 3 and Step 4; depending on the solution, this message may be relayed and verified offchain or sent via a slow message onchain. Instead, an intents system could easily use the Crosschain Broadcaster to store and verify these messages in a transparent, trustless way.

1. User deposits funds into an Escrow contract on Base
2. A solver sends funds to the user through a Fulfillment contract on Arbitrum
3. The Fulfillment contract calls the the Broadcaster contract on Arbitrum and publishes a message saying “solver X sent Y tokens to user Z at time T”
4. Back on Base, the Escrow contract calls the Receiver contract and validates the message in the Broadcaster on Arbitrum One; user funds are then released to the solver

In this case, the Fulfillment contract plugs into the Broadcaster on Arbitrum while the Escrow contract plugs into the Receiver on Base. Messaging pathways like this could be created in any direction using the same standardized set of Broadcaster contracts.

Breaking Down the Core Contracts

Broadcaster Contract

Broadcaster is one of, if not the simplest concept: it’s a contract that stores messages on a particular chain. Any user, called a Publisher, can submit a bytes32 message. After verifying it hasn’t seen the same message from that user before, the contract stores the message in its own storage slot. As soon as the message is stored in the Broadcaster, it has been “broadcast”.

When another chain wants to check if a given message was indeed broadcast, it just has to read that slot in the Broadcaster’s storage on the home chain and confirm the metadata.

BlockHashProver Contracts

To figure out the state of a remote chain, one must verify its block hashes. However, each rollup might store finalized block hashes using different methods. The job of a BlockHashProver is to get block hashes of a target chain from its home chain. It can accomplish this with two functions:

• getTargetBlockHash(…): when called on its home chain, it directly fetches the final block hash of its target chain from that chain’s state
• verifyTargetBlockHash(…): when called on a non-home chain, it uses a storage proof to check that a given homeBlockHash implies a specific targetBlockHash

A BlockHashProver effectively creates a one-way link between two chains. BlockHashProvers can also be daisy chained together across L2s and L3s, enabling robust routing between rollups.

BlockHashProverPointer Contracts

Because rollups are upgradeable, the hardcoded methods in a BlockHashProver may break if rollups change where they store block hashes. A BlockHashProverPointer can solve this by:

• storing the code hash of the current, correct BlockHashProver for a chain pair (i.e. home chain, target chain)
• updating the Pointer to a new version of the BlockHashProver that incorporates the rollup changes

The BlockHashProverPointer contract simply holds the code hash of the real BlockHashProver. That way, references to the Pointer address remain stable even if the underlying Prover changes. It is the responsibility of the chain owner to maintain the BlockHashProverPointers on their chain.

Receiver Contract

The Receiver contract on a local chain is responsible for verifying that a Broadcaster contract on a remote chain truly contains a message. To do so, it takes the following steps:

1. The user provides a list of Pointer addresses (i.e. the “route”) that leads from the local chain back to the remote chain in question along with the corresponding storage proofs
2. The Receiver contract calls or references each Pointer in turn, using the Provers they point to to verify block hashes hop-by-hop until it obtains the final block hash of the remote chain
3. Armed with that final block hash, the Receiver checks a proof that the remote Broadcaster’s storage slot indeed holds the user’s message

If all is well, the Receiver returns a confirmation along with the original broadcast timestamp.

Routes and IDs

Because every chain can reference many others, there must be a standardized way to identify which chain is being read from. The Crosschain Broadcaster Standard accomplishes this via a route-based “accumulator” method:

• Suppose you have a route: [PointerA, PointerB, PointerC]. At each hop, the local chain references that Pointer’s code to read or verify the next block hash.
• If the actual account you want to prove is address D, the combined remoteAccountId is keccak256(keccak256(keccak256(keccak256(0,A),B),C),D).
• This method guarantees a unique ID for any contract address given the exact route taken to get there.

So if different routes exist that eventually point to the same chain, that’s fine: they just produce different IDs. But from the local chain’s perspective, each route is an unambiguous path to verifying message data.

Conclusion

As the Ethereum ecosystem grows, so does the need for reliable, trustless Crosschain communication. The Crosschain Broadcaster Standard is a potential stepping stone towards that goal:

• It defines a simple interface for broadcasting 32-byte messages on any rollup chain
• It provides a universal way to verify those messages on chains with a common ancestor
• It is built around storage proofs rather than external relays, eliminating trust assumptions
• It provides forward-looking flexibility for rollups that are expected to evolve

These properties also align with Arbitrum’s vision for interoperability, which prioritizes interoperability building blocks that are:

1. Trustless: Crosschain communication should not introduce any new trust assumptions, or it risks undermining the core value proposition of blockchains today.
2. Cheap: Crosschain communication should not result in high fees that restrict accessibility.
3. Fast: Crosschain communication should occur much faster than L1 finality to help ensure practical functionality.
4. Accessible: Interoperability should be a feature available to everybody. Developers should have a clear path toward enabling Crosschain communication, with no vendor lock-in, politics, or boundaries.

While Broadcaster meets the criteria for trustless, cheap, and accessible, it is worth noting that the speed is limited by the finality of chains in a given route. If the Ethereum L1 anchors a route, then it cannot be faster than L1 finality; however, if an L2 anchors a route between L3s, then it can be faster than L1 finality. The latter is especially relevant for the Universal Intent Engine vision, which seeks to enable crosschain swaps and transfers for all Arbitrum chains (L2s and L3s) and EVM chains more broadly. For example, a full intents stack could enable fast fulfillment for end users while using Broadcaster for trustless settlement for solvers.

Whether or not the Crosschain Broadcaster Standard progresses is up to you, the community! If there is sufficient demand, Offchain Labs will set its sights on building out the complete implementation in collaboration with the Ethereum ecosystem. So if you’re looking to build crosschain applications with strong security guarantees, or if you’re just enthusiastic about multi-chain design, share your thoughts on the Eth Magicians post or contribute to the standard directly!

Introducing the Crosschain Broadcaster was originally published in Offchain Labs on Medium, where people are continuing the conversation by highlighting and responding to this story.

Blockchain applications today provide a robust foundation for an onchain economy. It has never been easier for a developer to launch an application or chain while benefiting from Ethereum’s security and composability. But as adoption grows, so do its challenges.

Today, developers and users live in a fragmented blockchain landscape. Applications operate on isolated networks, limiting the ability to interact and transact seamlessly. The dream of a decentralized, global supercomputer is within reach, but only if these networks can operate in harmony. Vitalik’s blog post on scaling highlights this challenge as well, among other emerging focus areas for Ethereum L1. Solving this challenge requires not just innovation but also a commitment to openness and collaboration.

We at Offchain Labs believe that Arbitrum can and will lead the way, and developers will have access to a suite of interoperability solutions in two distinct phases:

1. Intent-Based Interoperability: Targeting the end of Q1, Arbitrum chains will have access to crosschain token transfers and swaps in less than three seconds.
2. Crosschain Operations: Targeting the end of Q3 and pending approval from the Arbitrum DAO, we will enable crosschain operations in a fast, cheap, and trustless manner.

These developments are just a few of several foundational improvements that will unify the Arbitrum ecosystem. By establishing seamless connectivity and liquidity sharing, users and developers will experience Arbitrum chains as a unified whole — a platform where true interoperability is achieved without compromising on security, UX, and the freedom to build anything you want.

While these innovations will elevate the Arbitrum ecosystem, the impact extends far beyond a single network. By making these developments available across all EVM-compatible chains. Offchain Labs is doing more than just improving Arbitrum — we’re weaving a seamless fabric of connectivity throughout the entire Ethereum landscape. This universal approach to interoperability marks a significant step toward a truly unified blockchain ecosystem.

Arbitrum Interoperability

Offchain Labs, the initial builders behind the technology used by Arbitrum, will work closely with the Ethereum Foundation, interoperability protocols, and leading L2s to align with industry standards, research improvements and ensure the broad adoption of these tools and protocols. While interoperability standards are important, we recognize that true interoperability will only come through actual selection and implementation of standards, turning ideas into reality.

Offchain Labs believes that it is crucial for interoperability to maintain several key properties:

1. Trustless: Crosschain communication should not introduce any new trust assumptions, or it risks undermining the core value proposition of blockchains today.
2. Cheap: Crosschain communication should not result in high fees that restrict accessibility.
3. Fast: Crosschain communication should occur much faster than L1 finality to help ensure practical functionality.
4. Accessible: Interoperability should be a feature available to everybody. Developers should have a clear path toward enabling crosschain communication, with no vendor lock-in, politics, or boundaries.

This means Arbitrum’s interoperability modules would provide functionality allowing crosschain communication and chain abstraction without cascading security risks or unspoken tradeoffs.

A Universal Intent Engine

Supporting the vision of a unified Ethereum, at the heart of Arbitrum’s interoperability vision is a universal intents engine. This engine will power crosschain swaps and transfers for all Arbitrum chains and EVM-based chains in less than three seconds, eventually allowing users to initiate complex actions with a single wallet prompt. The components outlined below are just the first step we are taking toward the vision outlined above. As we work to improve on the most critical properties for cross-chain operations — being fast, cheap, and trustless — the engine’s core components will change.

Intents are a rapidly growing connective layer well-suited for the multi-chain world. By allowing users to express crosschain intentions for their assets, solvers can compete to find the most cost and time-efficient path to the desired state. Users and apps get their assets fast while handing off the complexities of routing and chain management. Many different teams have laid the groundwork to make intents possible today.

The technology layer that powers intents is still nascent, and we plan to deliver upgrades on the protocol and application layer to improve trust, cost, and UX. Our initial intents engine consists of four components:

• Message Standard: All Arbitrum chains will be able to adopt a standardized message format for intents. Several standards show promise, including ERC-7683, 7786, and 7841. Note that these are not mutually exclusive and the combination of these standards can offer a powerful experience. Standardizing the message layer will reduce friction for solvers and intent solutions.
• Broadcast Standard: All Arbitrum chains will have standard contracts that ensure trustless communication, guaranteeing a secure message-passing connection between Arbitrum chains and the broader EVM ecosystem.
• Fast Settlement: Arbitrum chains will have access to various fast settlement solutions, including the already live Fast Withdrawals, third party fast bridges, and an upcoming native ZK integration. A shorter settlement time lowers the capital requirements for solvers and fast bridges to rebalance funds, meaning savings can be passed on as reduced user fees.
• Intent Dissemination Feed: Arbitrum chains and applications will have access to a universal feed to publish users’ intents. Initially, this component will depend on third parties, but Offchain Labs is exploring trustless solutions that seamlessly integrate with all available setups. This will allow users, developers, and solvers to have a frictionless experience in crosschain transfers and swaps.

Wen Interop?

Arbitrum’s Universal Intents Engine will launch in Q1 on an initial set of chains, making seamless cross-chain asset transfer a reality. This rollout will expand to encompass all chains and key applications on Arbitrum One, enabling secure, fast, and efficient intent execution ecosystem-wide. Offchain Labs is collaborating with other L2s and interoperability protocols in an EF working group to develop smart contracts that comply with ERC-7683.

To ensure a smooth expansion to new chains, The Arbitrum Foundation has confirmed that it will run a Solver Loan Program (SLP). The SLP will provide the capital to solvers willing to support intents across the Arbitrum ecosystem. The SLP will begin by bootstrapping ETH and USDC routes between chains, with plans to expand to additional tokens later in the year. Through this program, Arbitrum chains can also loan their own funds to establish routes for their custom gas and governance tokens.

On Our Radar

• Fast Settlement Solutions: Expanding on the live Fast Withdrawals feature, additional solutions, including a native ZK integration and support for 3rd-party pre-confirmation products, are being developed to accelerate settlement, pre-confirmation and optionality for chains.
• Developer Tooling: Expansion of the intent design space, including the enablement of complex interactions beyond simple transfers and swaps.
• Crosschain Standards: Establishing compatibility with widely accepted EVM standards, including ERC-7683, ERC-7785 and ERC-7828, to help ensure seamless interoperability across chains.
• Refining the UX: Exploring EIP-7702 and account abstraction to offer single-signature crosschain transactions.

By combining immediate advancements with long-term innovation, Arbitrum is delivering a cohesive and forward-looking ecosystem for users and developers alike. Offchain Labs is committed to continuously refining the intents stack — in tandem with many ecosystem partners — so that fast, trustless, cheap interoperability is available to all.

The Road Ahead

Through the Universal Intent Engine, the Arbitrum ecosystem will have access to crosschain token transfers and swaps in less than three seconds, but such improvements can’t stop there. Offchain Labs is committed to making crosschain operations better. Developers should expect to hear more about these plans soon.

Through these primitives, developers will have access to a comprehensive interoperability suite, enabling them to build applications that interact across chains without compromising security, decentralization, or speed. Users stand to benefit the most, where any action will be just one wallet prompt away. Upon completion and DAO approval of the interoperability suite, a user will gain access to any chain(s) of their choice, regardless of where their assets are.

Users will have access to any EVM chain or application on Arbitrum.

A unified Ethereum would not be possible without the contributions of others, including L2s, the EF, Espresso, Uniswap, Across, LayerZero, Chainlink, Polymer Labs, Open Zeppelin, Caldera, Reservoir, Li.Fi, Everclear, and many more. If you are building interoperability solutions or standards, we invite you to join us in shaping the next iteration of both Arbitrum and Ethereum. Together, we can make a trustless, decentralized future a reality.

If you are in the Arbitrum ecosystem and want to enable interoperability today, please refer to this document for more technical details.

Bringing Interoperability to Arbitrum and Ethereum was originally published in Offchain Labs on Medium, where people are continuing the conversation by highlighting and responding to this story.

Offchain Lab’s partner studio and venture capital arm, Tandem, has invested in Camelot, an Arbitrum native decentralized exchange (DEX), solidifying its position as a native DEX in the Arbitrum ecosystem.

Originally launched without VC funding and entirely bootstrapped by the Arbitrum community, Camelot has become the largest protocol exclusively native to Arbitrum, exemplifying the strength and potential of community-driven development.

Iron Boots, a cofounder of Camelot, said that when DeFi first gained traction, a lot of the relationships built around it were short-term and yield-focused. Camelot, however, took a different approach.

“One of the key aspects of our vision has always been to build long-term relationships. It’s not just about the rewards we exchange; it’s about working together to create something for the future,” Iron Boots said.

From its inception, Camelot has been driven by a clear mission: to foster innovation, collaboration, and sustainable growth within a thriving blockchain ecosystem. This vision led the team to focus exclusively on building a decentralized exchange tailored to the unique needs of Arbitrum.

For the first six months from its inception, Camelot spent time and resources to convince users to join Arbitrum, this was because Camelot recognized Arbitrum as a network beyond its technical capabilities, offering an organic and vibrant ecosystem for developers and projects. The team also aligned with Arbitrum’s core mission of making blockchain more scalable and secure for everyone.

This fundamental alignment of values between Camelot and Arbitrum served as a cornerstone for the DEX’s approach. Rather than chasing short-term gains, Camelot prioritized structuring itself to fully commit to long-term, sustainable goals.

“Camelot has become a cornerstone of the Arbitrum ecosystem, providing a robust decentralized exchange and a hub for innovation and collaboration. Their commitment to supporting builders, fostering community growth, and aligning with Arbitrum’s vision has played a critical role in the network’s success,” A.J. Warner, Chief Strategy Officer at Offchain Labs said. “Camelot’s presence strengthens our ecosystem, and their focus on sustainability and long-term value creation continues to drive meaningful progress for all participants.”

Today, Camelot is not only a liquidity hub on Arbitrum but also a launchpad for new projects and a community-driven platform for builders. The DEX has over 75 partners and $46 billion in volume traded, generating over $48 million from fees and a TVL of $120 million. Additionally, Camelot was one of the first protocols to expand beyond Arbitrum One and Nova and has now been deployed on over 14 different Arbitrum chains.

Tandem’s investment in Camelot highlights Offchain Labs’ confidence in its mission and potential. “We are committed to supporting projects that push the boundaries of what’s possible in DeFi. Camelot’s approach to creating sustainable, community-driven solutions in the Arbitrum ecosystem made it a natural fit for our portfolio,” Ira Auerbach, Head of Tandem, said.

As Arbitrum expands, Camelot will be at the forefront. Although initially focused on Arbitrum One, Camelot now extends its reach to other Arbitrum chains. This shift has broadened Camelot’s role in the Arbitrum ecosystem, becoming a unifying force for liquidity across various networks.

“It’s not just about building technical bridges between chains; it’s about making all these different chains feel like an integral part of Arbitrum. A key part of our vision moving forward is figuring out how to create a cohesive and aligned ecosystem across all of them,” Iron Boots said.

Tandem by OCL Invests in Camelot, the Largest Native DEX on Arbitrum was originally published in Offchain Labs on Medium, where people are continuing the conversation by highlighting and responding to this story.

Offchain Labs is committed to building and innovating in ways that will enhance scalability, performance, and usability across the Arbitrum ecosystem. Over the past year, we have been carefully listening to the ecosystem’s feedback on the value of natively enabling vertical scaling and throughput capability increases.

As detailed in our latest technical roadmap, Offchain Labs’ recent focus has been bringing exciting, value-differentiating technologies, such as BoLD, Stylus, and Timeboost, to life. However, we wanted to assure the community that we are also actively working towards relieving throughput constraints and scaling to meet the demand for EVM blockspace through vertical scaling.

Future-oriented scalability: A focus on alt-clients and beyond

Nitro, the tech stack that powers all Arbitrum chains today, is engineered to be opinionated and purpose-driven. It is explicitly tailored to meet the needs of Layer-2 solutions. Nitro’s architecture is intentionally designed to allow for faster blocktimes, cheaper transactions and a more efficient EVM. This enables the unique customizations Orbit teams are making today and is the reason why Offchain Labs was able to ship Arbitrum with fraud proofs on day one.

At present, hardware and software optimizations enable blockchains to handle high transaction volumes with speed and reliability. But as Layer 2 (L2) demands evolve, our engineering approach is evolving right along with them. Offchain Labs is now in the process of testing the reorientation of Nitro’s development to support alt-client solutions — as stated in the technical roadmap.

Our objective in this work is straightforward: Alt-client development will be a top priority for 2025 as Offchain Labs continues to contribute to the expansion of Arbitrum’s capacity and capability to support the growing ecosystem of projects. We are excited to work with client teams to build the path for an ultra-high-throughput future for Arbitrum chains.

Currently, the Offchain Labs engineering team is evaluating Reth, Erigon, and Nethermind as alt clients — in parallel with Geth optimizations and improvements. Although we are still in the early stages of this process, we intend to keep the following objectives in mind:

• Performance improvement (i.e., throughput increases)
• Customizability opportunities
• Reduced node operating costs
• Alignment with the broader Ethereum ecosystem
• Enhance ecosystem security and client diversity

From what we have gathered so far, our engineering team is leaning towards a Reth implementation, but we are approaching this decision with careful due diligence to determine what is the optimal long-term choice.

Erigon remains an appealing option, particularly as a more accessible solution for immediate archive node optimizations. If our evaluations show that Reth is the right path forward, we will share the data and reasoning behind our decisions transparently.

Meanwhile, we have reviewed publicly published benchmarks from the Nethermind team showing that their client is highly performant.

This update reflects Offchain Labs’ intent to stay agile, adaptable, and future-ready. Whether through Reth, Erigon, Nethermind or a combination, we are committed to creating solutions that can enhance Arbitrum’s throughput and efficiency and aligning with Ethereum’s evolution. As always, we will keep the ecosystem informed and engaged as we continue this journey.

High throughput scaling: today and tomorrow was originally published in Offchain Labs on Medium, where people are continuing the conversation by highlighting and responding to this story.

Blockchain technology has been rapidly evolving, bringing incredible opportunities for growth and innovation. However, as the space expands, developers and users are seeking ways to make blockchain technology more accessible, secure, and decentralized.

Arbitrum Orbit’s technology stack is an essential piece in blockchain scaling. Developers can create and customize their chains without getting bogged down in technical complexity, reducing the work they need to do to get to where they want to go. Users reap the benefits of faster, more cost-efficient transactions compared to using Ethereum.

At Offchain Labs, we know that there are various types of onchain applications that developers want to build and that there is never a one-size-fits-all solution for enabling these applications and the innovation teams are striving for. Using Orbit, we have adopted the mantra of Your Chain, Your Rules to ensure chain developers can adapt and evolve their applications based on their unique needs and innovate in a way that works for them.

This means that regardless of whether developers are building a large-scale application or designing a dedicated ecosystem, Orbit will provide the developer with more ownership and customizability over the chain. This will include increased speed, custom gas tokens, governance tools, various validation strategies, novel ways to deal with MEV, smart contracts in new languages, and more. Each Orbit team will have the power to decentralize and grow however it wishes.

With all of this in mind, we want to share a little more about Arbitrum Orbit’s current state, our vision for its future, and what this means for current and prospective teams using Orbit chains.

Phase one, *rapid expansion*

Since its launch in 2023, Arbitrum Orbit has sparked an explosion in innovation across Ethereum. Pioneering blockchain developers quickly recognized the opportunity to build new, performant, and feature-rich rollups, resulting in industry-defining app chains and onchain ecosystems. As of October 1st, 2024, the Orbit ecosystem has seen over 30 chains reach mainnet, with over $200 million in TVL bridged.

The Orbit ecosystem contains the full breadth of blockchain applications and use cases such as gaming, DeFi, Consumer, DePin, RWAs, and more.

Applications that have built a solid user base and product are now evolving and require more bespoke designs and systems to serve their growing needs. This is what Orbit is designed to do. With Orbit, developers can aggregate their services into a single chain instead of dealing with the complexity of deploying across multiple blockchains. This allowed them to build faster, more scalable, and interoperable applications.

Phase two, the *evolution*

Following the explosion comes the evolutionary phase of the Orbit ecosystem, and we are looking to improve in a handful of areas over the coming months.

Customizability

Orbit chains are designed so that it is possible to choose the exact technology stack you would like to use. This means we want to provide more customizable offerings for Orbit chain users. Some exciting developments that we are working on include:

• Expanding gas token offerings,
• Having the option to deploy a bridged form of USDC through EVM blockchains, with the possibility of having native issuance in the future and
• Access to the new transaction ordering policy that Offchain developed, Timeboost.

Decentralization

At the heart of what makes blockchain transformative is decentralization. BoLD, which stands for Bounded Liquidity Delay Protocol, will be an upgrade to the Arbitrum dispute protocol. It will enable anyone to validate the state of the chain and propose state roots to L1 Ethereum, making one great stride towards enhancing permissionless and decentralized validation and improving the security of withdrawals to L1 Ethereum.

As part of BoLD, a novel feature called Censorship Timeout will be enabled that improves the censorship resistance properties for Arbitrum Orbit chains — particularly L3s. Censorship Timeout introduces a way for the force inclusion window to be lowered following repeated or sustained sequencer censorship or downtime. Arbitrum Orbit chains get this benefit for free by adopting to use BoLD. Read more about this feature in this document.

DevEx

We want blockchain developers to be able to design and build highly customizable applications that meet their ever-changing needs. For this reason, we’re looking to offer flexible tools and a customizable tech stack to enable them to create more specialized and innovative solutions.

Alongside improvements to the Orbit Admin UI (user interface) and the Orbit SDK (software development kit), the Stylus SDK is another central area of focus for us at Offchain Labs.

Stylus enhances smart contract development on Arbitrum by allowing developers to write contracts in any language that compiles to WebAssembly, such as Rust, C, and C++. This flexibility lets developers use familiar, efficient, and secure programming languages while also allowing them to access tooling and libraries belonging to new languages supported by Stylus, unlocking new possibilities.

Native interoperability

As the universe of chains develops, native interoperability becomes essential. An important aspect of Orbit is its interconnectivity, which enables networks and services to flow effortlessly.

To help ensure that this becomes a seamless reality, we’re working on multiple interoperability solutions, including:

• Layer leap: This feature will allow users to move funds directly from Ethereum to an L3 Orbit chain in one transaction. This helps with interoperability by reducing the number of transactions and overhead required from the end user when using app chains on L3s.
• Fast withdrawals: These will be available for Arbitrum AnyTrust chains. They will enable Orbit chains to reach fast finality and process transactions in as little as 15 minutes instead of the initial 7-day challenge period. This will be achieved through a committee that must unanimously approve the transaction. Fast withdrawals will help with interoperability because it reduces the time it takes to transfer assets between Orbit chains, making cross-chain interactions a tad more seamless.
• Chain mesh: Previously chain clusters. We are working on a native solution for Arbitrum chains to allow trustless, faster communication and settlement times. This innovative approach will enable Orbit chains to work together more efficiently, optimizing the use of resources and enhancing security.

Performance

In addition to allowing developers to write code in additional programming languages, Stylus is designed to optimize performance by introducing a co-equal virtual machine completely interoperable with the EVM that is designed to execute WASM instead of EVM bytecode. WASM languages such as Rust can provide significantly better performance and efficiency for computationally intensive applications. This makes it possible to do previously unfeasible operations, such as various types of on-chain proof verification.

We are also looking to invest in alternative client implementations to scale Arbitrum Orbit chains vertically, bringing further customizations to Orbit chains and allowing further modularity.

Looking ahead

We envision that the future of Orbit chains will resemble closely connected constellations or meta-structures that bring together multiple blockchain networks into a cohesive, interconnected ecosystem. Arbitrum technology will connect these constellations and ensure they remain highly interoperable while serving a specific community or function.

With this roadmap, Arbitrum Orbit is well-positioned to lead the next phase of blockchain innovation, empowering developers, users, and ecosystems to thrive in an ever-evolving, decentralized world.

Your Chain, Your Rules, with Arbitrum Orbit was originally published in Offchain Labs on Medium, where people are continuing the conversation by highlighting and responding to this story.

Tl;dr Your Chain, Your Rules. As Arbitrum sees massive adoption by those building applications, infrastructure, and Orbit Chains, we’re hard at work on a variety of technical updates. These updates ensure that the usability, interoperability, and utility of Arbitrum continues to lead the adoption curve. Outlined below is the roadmap we intend to deliver, making your vision of blockchains a reality.

Your Chain, Your Rules.

As we set our (technical) course for the upcoming year, we at Offchain Labs remain steadfast in one of our core values: Your Chain, Your Rules. We continue to believe that blockchains are building a better internet, one with users and developers at the core. Using Arbitrum technology, builders can create powerful onchain apps and vibrant blockchain ecosystems. Users and institutions can safely steward themselves in a natively digital economy. Communities have the power to self-govern.

With this in mind, we encourage everyone interacting with Arbitrum chains to be visionaries, to stay curious, and to move forward with confidence knowing the tech just works.

The Roadmap

When we launched Arbitrum on August 31, 2021 (Arbitrum Day), we tackled the first major hurdle in blockchain adoption: scalability. Over the past three years, we’ve continued to scale, introduced entirely new capabilities, and created the most technically sound and open blockchain platform available.

As blockchain technology expands its reach across industries and gives rise to new ones, builders and users face the very challenges we’re committed to solving: fundamental usability, driving adoption, offering robust decentralization guarantees to users, and an infrastructure layer that just works.

We’re bridging the gap for builders and users by simplifying interactions with Arbitrum chains, driving wider adoption. Interoperability is at our core, allowing seamless navigation between chains using secure technology. We’re abstracting complex decision-making processes about ‘which stack or chain to use’ and creating the unified system.

It’s simple…Your Chain, Your Rules — giving you the freedom to innovate and build on a foundation you can trust.

DevEx, UX, and Adoption

To drive adoption we need to make building on blockchains more expressive, performant, and accessible for developers. Enter Stylus.

Stylus transcends the constraints of building on Ethereum by allowing developers to program in languages that compile to WebAssembly (WASM), like Rust, C, and C++.

Solidity has an important part of our history and an important part of our future as well; Arbitrum’s support for EVM isn’t going anywhere. At the same time, we must recognize that the number of Solidity developers and the corpus of existing code is far smaller than traditional programming languages. Stylus allows us to be more inclusive and welcome in a growing developer base without compromising the EVM experience for those who love it.

Stylus meets the growing need for performant and secure smart contract languages, while simultaneously expanding the design space for increasingly expressive onchain applications. In addition, Stylus is an efficient execution environment leading directly to gas savings for complex smart contracts. With Stylus, computation and memory costs can be significantly cheaper.

And you don’t have to wait…

If you’ve been around the Arbitrum ecosystem for a while, you know some of the biggest ecosystem launches happen on Arbitrum Day. (Well ok ok technically, Arbitrum Day falls on a holiday weekend in the US this year, so we’ll be observing it a few days late).

Arbitrum Stylus will go live on Arbitrum One and Nova mainnet on Arbitrum Day ushering in a new phase of innovation across the ecosystem and make the developer and user experiences even better. It’s the biggest execution layer upgrade to ever hit our industry.

Decentralization

The core ethos of blockchain technology, which values decentralization and trustlessness, is core to everything we build at Offchain Labs and our future development plans for the Arbitrum technology stack. We are working on a number of near-term and future developments to strengthen foundational infrastructure, ensuring decentralization remains not just a theoretical concept, but a practical reality in the ecosystem:

• BoLD (H2 2024): In addition to improved security, BoLD enables safe decentralized validation and moves Arbitrum closer to being a Stage 2 rollup, the final stage in L2 Beat’s stage definitions.
• Censorship Timeout (H2 2024): Building upon BoLD, Censorship Timeout limits the negative impact to Arbitrum chains from a repeatedly censoring or offline sequencer, potentially due to an attack. This provides stronger guarantees of censorship resistance to Arbitrum chains, and improves user fund access.
• Decentralized Sequencer (likely 2025): Decentralizing the Arbitrum sequencer is the last step in Arbitrum’s decentralization roadmap. A decentralized sequencer distributes the responsibility of transaction ordering across a broader, decentralized network of participants, reducing the risk of censorship attacks and enhancing reliability.

At Offchain Labs, we believe in the core ethos of blockchain tech and build products for decentralized adoption. The features mentioned in this post can be adopted by Arbitrum Orbit chains when available, or the Arbitrum DAO can vote in any or all of these technical upgrades to the chains it governs (Arbitrum One and Arbitrum Nova).

Interoperability and Horizontal Scaling

The introduction of Arbitrum Orbit ushered in a new era, empowering teams to innovate solutions for their own specific use cases. Arbitrum Orbit allows developers to customize their chains in any way they see fit. Our guiding principle remains: Your Chain, Your Rules. As builders focus on pushing boundaries, we’re committed to implementing significant performance and interop improvements by tackling fundamental engineering challenges. Our long-term strategy combines vertical and horizontal scaling efforts, enabling developers to accomplish more.

To unify the Arbitrum Ecosystem (Arbitrum Orbit, Arbitrum One, Arbitrum Nova, and Ethereum) we’re building towards frictionless interoperability between chains rooted in fast communication. Optimistic rollups offer the lowest cost and greatest flexibility, but their main barrier to horizontal scaling is the confirmation delay introduced by the challenge period. Longer confirmation time means that worst-case cross-chain communication may require days or alternatively placing trust in 3rd-parties.

We’re working on several interop solutions that will reduce these confirmation delays and enable horizontal scaling:

• Fast Withdrawals (Q3 2024): The imminent release of Fast Withdrawals will enable AnyTrust chains to bypass the confirmation delay, and settle to their parent chain within minutes. These fast confirmations will enable sibling L2s (or L3s) to communicate quickly with one another, thereby enabling developers to shard workloads and scale horizontally.
• Chain Clusters (2025): Looking ahead into next year, we plan to further expand the toolbox of developers to horizontally scale Orbit chains with the release of Chain Clusters. By allowing multiple Orbit chains to closely align their ecosystem and infrastructure, Chain Clusters can be used to reduce cross-chain communication time from minutes to near-instant.

Performance and Efficiency

From the very beginning, back in 2014, Arbitrum’s design has focused on performance and efficiency. Now, we’re looking to deliver the next iteration of enhancements in compute efficiency and performance with fundamental optimizations to execution.

• Multi-client support (H1 2025): Arbitrum Nitro is the node software that powers all Arbitrum-based chains and is built on Geth, a Golang implementation of the execution specification for L1 Ethereum. Since the debut of Arbitrum Nitro back in August 31, 2022, many new Execution Layer (EL) client implementations have launched or improved significantly — all with varying and unique value propositions and optimization targets. As the stability and quality of these alternative clients have improved, Offchain Labs has been working towards readying the Arbitrum stack to support alternative clients.

When we evaluate other clients, our main objective is to optimize at-head block production speeds which over time will (1) reduce the hardware cost of existing node operators and (2) pave the way for the safe increase of the speed limit (i.e. target throughput) on Arbitrum chains.

We have already begun testing and evaluating performance and benchmarks for several clients including Paradigm’s newly released Reth 1.0, Erigon 3.0, and Nethermind with the goal of delivering a production-ready multi-client implementation in 2025 and streamlining the process of adding additional clients down the road. Although our current analysis suggests that some alternative clients are still behind Geth in a few performance benchmarks, we believe that it’s prudent to ready the path for Arbitrum adoption as these clients further optimize.

• Adaptive Pricing (H1 2025): On current EVM chains, gas limits are set to prevent nodes from over-consuming the most scarce computational resource. This means that the gas limit for a chain is always a worst-case assessment, designed to protect against a transaction load that uses a node’s most constrained resource.

In contrast with a worst-case approach, Adaptive Pricing considers the actual resources being used and dynamically sets the gas limit accordingly. With Adaptive Pricing, the chain will only raise fees and throttle down resource consumption when a particular resource is approaching its actual limit, as opposed to a hypothetical maximum of what resources a different transaction might have used.

Adaptive Pricing will further enable scaling by allowing smart contracts to more efficiently use the full resources made available by nodes, and operate much closer to the true gas limit. Overall performance will increase without increasing the capacity of the network’s nodes. Adaptive Pricing also improves resilience versus extreme traffic patterns (e.g. inscriptions), where usage patterns change radically, but temporarily, by dynamically lowering gas limits only when necessary.

Zero-knowledge proofs

Offchain Labs is committed to scaling Ethereum with the best possible technology stack. By constantly working at the limits of available technology, we can identify improvements to deliver into our scaling solutions. While today it’s clear that from the perspectives of stability, maturity, cost, and security, Arbitrum Nitro is the best stack to scale Ethereum, our research team has identified several paths where we can incorporate productive uses of zero knowledge (ZK).

In his 2023 medium post as well as recent talks at EthCC and SBC, our Chief Scientist Ed Felten presented a hybrid construction for how ZK can be integrated into Arbitrum chains. One particular area of active research studying ZK:

• ZK+Optimistic Hybrid Proving: In the Arbitrum rollup and dispute resolution protocol, ZK proofs could eventually be used to instantly confirm assertions, acting as an optional and fast path to confirmation on the parent chain. Optimistic proving could still be used if ZK proofs are not provided. This enables users and developers on Arbitrum chains to access very fast native interoperability on an as-needed basis.

Always Looking Ahead

At Offchain Labs we are committed to creating solutions before problems arise. The monumental efforts to build three products ready for deployment this year — Stylus, BoLD, and Timeboost (click to learn more) — are proof points of Offchain Labs leading from the front. These innovations will make blockchains more accessible and support core values of decentralization.

Our deep bench of researchers, engineers, product managers, partnerships, marketers, and operations professionals push the boundaries of what can be done in this space. We build our products for you to innovate with the assumption that your infrastructure just works.

There is a lot more on the roadmap, but we wanted to share some of the mountains you’ll start to see moving in the near term.

Your Chain, Your Rules: Offchain Labs’ Technical Roadmap to Fuel Arbitrum Innovation was originally published in Offchain Labs on Medium, where people are continuing the conversation by highlighting and responding to this story.

Offchain Labs is thrilled to announce another milestone in the evolution of Arbitrum: the testnet availability of Arbitrum BOLD — the next-generation dispute resolution protocol with working, interactive fraud proofs for optimistic rollups. Building upon the foundation laid in our original announcement of BOLD on August 3, 2023, this announcement marks another step towards fully permissionless validation on Arbitrum chains and greater decentralization.

Fraud proofs on rollups are only as useful as the dispute process that runs them. Arbitrum has been secured using fraud proofs in production from day-one, and the Offchain Labs team has continued to iterate on creating a dispute resolution protocol for Arbitrum that is permissionless, safe, and solves many of the pitfalls other designs suffer from. BOLD guarantees a fixed upper-bound on the confirmation of Arbitrum states on Ethereum and allows a single, well-resourced party to defend claims against many adversaries without needing to play 1-vs-1 games against them.

Arbitrum has always been committed to scalability, efficiency, and security. As part of Offchain Labs’ comprehensive plan to ensure BOLD is rigorously tested and robust in design, we’ve deployed the implementation of BOLD on a public testnet. The BOLD-enabled public testnet validates and posts assertions to Ethereum Sepolia and gives the community a chance to deploy a BOLD validator to see this bleeding-edge dispute protocol in action. Shortly after, we expect a proposal will be made to activate BOLD on Arbitrum Sepolia, followed by a Tally vote.

Why is permissionless validation important for decentralization & Arbitrum?

So, what exactly does permissionless validation mean for Arbitrum? In essence, it empowers anyone to secure claims made about Arbitrum’s state on Ethereum. That is, withdrawals from Arbitrum back to Ethereum can be verified or challenged by anyone in the world, ensuring the correct history always remains correct. Currently, Arbitrum validators are allow-listed, but with BOLD, the use of a permissioned list of validators will no longer be necessary. This democratization of validation will not only enhance the security and resilience of the network, but also foster greater decentralization and resiliency within the ecosystem.

BOLD’s benefits for the Arbitrum community include:

• Permissionless Validation: Participants can run their own validator nodes and contribute to the consensus process, helping to secure the network and validate withdrawals back to Ethereum.
• Enhanced Security: BOLD taps into the 10 years of experience the Offchain Labs team has in designing interactive proving protocols to create a new system for Arbitrum that is resilient to delay attacks and allows a single, well-resourced honest party to defeat many evil parties without needing to play 1-vs-1 games. Honest BOLD validators will win against evil claims within a fixed upper-bound of 7 days and have their stakes reimbursed when disputes are resolved, so long as they follow the protocol.
• Pooled Challenge Funding: Issuing a challenge requires significant funding. However, anyone can create a trustless smart contract to pool funds together and defend Arbitrum against invalid claims, or challenge invalid claims posted by others.
• Mathematical Foundations: After over a year in development, the Offchain Labs research team has produced formal safety proofs for BOLD. The BOLD smart contracts are currently being thoroughly audited by Trail of Bits.

Getting Closer to Stage Two

In his recent blog, “Ethereum has blobs. Where do we go from here?” Vitalik writes about many aspects of improving Ethereum L2s, including the need for continuous improvements to security and decentralization.

BOLD has the potential to take another major step for Arbitrum along this journey by addressing the (currently yellow) State Validation wedge in the L2 Beat risk analysis pie chart. L2 Beat’s commentary currently notes:

Fraud proofs allow 14 WHITELISTED actors watching the chain to prove that the state is incorrect.

By replacing the allowlisted validators with permissionless validators via BOLD, Arbitrum chains will be able to address this particular concern and move further towards greater decentralization and achieve even greater Ethereum alignment.

This sounds cool! How do I learn more?

The launch of BOLD on a public testnet is the first step of many on the roadmap to bring BOLD to mainnet readiness and, eventually, to Arbitrum One and Nova via a DAO vote. Below are a few great resources to learn more about BOLD and stay up-to-date with product updates!

• Read the BOLD Gentle Introduction docs for a primer on how BOLD works and why we built it for Arbitrum!
• To view BOLD’s current implementation & specification, check out the BOLD Github repository!
• Get first-hand experience running an honest or malicious BOLD validator (i.e. either to defend a network or attack a network) by following this guide.
• Check out the BOLD testnet block explorer!
• Read the updated BOLD whitepaper, which covers the formal specifications of BOLD alongside mathematical safety proofs!
• A deep dive into how BOLD is implemented can be found in the Technical Deep Dive into Arbitrum BOLD
• If you’re interested in the economics underlying BOLD disputes, see “The Economics of Disputes in Arbitrum BOLD”

In addition, we’ll be having a live AMA on “Uncovering BOLD & Permissionless Validation” on Thursday, April 18th at 11:30 AM ET here, where the big brains behind BOLD will answer questions.

Arbitrum BOLD Testnet Live: The Next Step in Decentralization was originally published in Offchain Labs on Medium, where people are continuing the conversation by highlighting and responding to this story.