Across Protocol

Overview of Across Protocol

Across Protocol occupies a central role in the cross-chain landscape as an interoperability layer designed to make moving value between networks feel as simple as a single transaction. As the blockchain ecosystem has fragmented into dozens of execution environments, each with its own liquidity, applications, and communities, the need to move assets between them has become one of the defining problems of decentralized finance. Across was conceived as a direct answer to that problem, prioritizing speed, cost, and safety in equal measure.

The protocol differentiates itself from the broader category of bridges by treating the user experience as the product and the underlying mechanism as an implementation detail that should remain invisible. A person bridging funds with Across does not need to think about relay chains, message verification windows, or wrapped-asset risk. They simply choose a source chain, a destination chain, and an amount, and the protocol handles everything else. This deliberate focus on simplicity, combined with a robust economic and security architecture, is what has allowed Across to scale to billions of dollars in volume and a user base in the millions.

What Is Across Protocol

Across Protocol is a decentralized, non-custodial bridge that facilitates the transfer of tokens between different blockchain networks. At its most basic level, it allows a user to deposit an asset on one chain and receive a corresponding asset on another chain almost immediately. Unlike centralized bridges or exchanges that take custody of user funds during a transfer, Across never holds user assets in a way that exposes them to counterparty risk. The protocol is governed by its community and powered by smart contracts deployed across every network it supports.

The defining characteristic of Across is its intent-based architecture. In this model, a user does not manually execute each step of a cross-chain transfer. Instead, they sign a request that specifies the outcome they want: a particular token, in a particular amount, delivered to a particular address on a particular destination chain. This request, often described as an intent, is then broadcast to a network of relayers who compete to fulfill it. Because relayers use their own capital to deliver funds to the user immediately, the experience feels instantaneous even though the underlying settlement that reimburses the relayer happens afterward.

This design makes the Across Bridge fundamentally different from older bridging approaches. Traditional bridges often require users to wait for the slow finality of canonical messaging systems, sometimes for many minutes or even hours, and frequently introduce wrapped representations of tokens that carry their own liquidity and trust assumptions. Across removes these frictions by separating the fast delivery of funds from the slower, more deliberate process of settlement and reimbursement. The user gets speed; the protocol gets security; and relayers earn a fee for providing the capital and taking on the short-term timing risk.

Mission and Core Philosophy

The mission of Across Protocol is to make crosschain transfers fast, cheap, and secure for everyone, from first-time users moving small amounts to institutions moving millions. Across is built on the conviction that interoperability should not come with hidden costs, opaque fees, or custodial risk. The protocol treats every transfer as a commitment to deliver funds reliably, regardless of size, and aims to make that commitment without compromising on the decentralization that defines the broader ethos of the space.

Three principles guide nearly every decision in the protocol. The first is speed by default, the idea that users should not have to wait for funds and that the fast path should be the normal path rather than a premium feature. The second is cost minimization, the belief that users should keep as much of their money as possible and that a bridge should not extract aggregator markups or bury hidden charges in an exchange rate. The third is decentralized security, the principle that no single entity should be able to control or seize user funds and that the system should remain permissionless, with anyone able to participate as a relayer or liquidity provider.

These principles are not merely aspirational. They are encoded in the structure of the protocol itself. The competitive relayer network exists to drive down fees and delivery times. The non-custodial smart contract design exists to remove counterparty risk. The optimistic verification system and the absence of privileged multisig control exist to keep the protocol decentralized and resistant to single points of failure. Together they form a coherent philosophy in which user experience and trustlessness are treated as complementary rather than competing goals.

How Across Differs from Other Bridges

The cross-chain ecosystem contains many bridges, and they vary widely in their architecture, security assumptions, and user experience. Across distinguishes itself across several dimensions that together define its competitive advantage. The most important is the intent-based model, which decouples the moment a user receives funds from the moment the protocol settles the underlying accounting. Where many bridges make the user wait for the entire process to complete, Across makes the user wait only for a relayer to act, which typically happens within a second or two.

A second major difference is the absence of wrapped tokens in the user-facing flow. Many bridges mint synthetic representations of assets that must then be redeemed or swapped, fragmenting liquidity and introducing additional trust assumptions. Across delivers the canonical or natively recognized asset on the destination chain, so users end up holding the token they actually want rather than a derivative that depends on the continued solvency of a bridge contract.

A third difference is the economic structure. Across is designed to minimize fees rather than maximize extraction. Because relayers compete to fulfill intents, the cost of a transfer is driven toward the true economic cost of providing the service plus a thin margin, rather than an arbitrary spread set by a single operator. There are no aggregator markups layered on top, and the price a user is quoted is the price they pay. Combined with deep, unified liquidity and a proven security record, these differences explain why Across is frequently chosen as the bridging layer inside other major applications rather than competing only for direct end users.

How Across Protocol Works

Understanding how Across Protocol works requires looking beneath the simple user interface to the coordinated system of smart contracts, relayers, and verification logic that makes near-instant bridging possible. The protocol is best understood as a marketplace for fulfilling cross-chain intents, in which users post requests, relayers fulfill them with their own capital, and a settlement layer reimburses relayers once the validity of each transfer has been confirmed. This separation of concerns is the key to delivering both speed and security at the same time.

Intent-Based Architecture

The foundation of Across is its intent-based architecture. An intent is a signed expression of a desired outcome rather than a prescribed sequence of operations. When a user wants to move funds, they deposit their tokens into the Across smart contract on the source chain and specify the destination chain, the token they want to receive, the recipient address, and the maximum fee they are willing to pay. This deposit, together with its parameters, constitutes the intent.

Because the user has expressed only the outcome they want, the protocol is free to choose the most efficient way to satisfy it. This is a powerful abstraction. The user does not need to know which relayer will fill the order, how the relayer sources liquidity on the destination chain, or how the relayer will later be reimbursed. They only need to know that, once their deposit is confirmed, the funds they requested will arrive at the destination. The intent-based model turns bridging from a multi-step technical chore into a single declarative action, which is a large part of why the Across Bridge feels so much faster and simpler than traditional alternatives.

Intents also create a competitive environment. Since any relayer can choose to fill any intent, relayers compete on speed and price to capture the associated fee. This competition continuously pushes delivery times down and squeezes fees toward their economic minimum. The architecture therefore aligns the incentives of users, who want fast and cheap transfers, with the incentives of relayers, who want to earn fees by being the fastest and most efficient fulfillers of demand.

The Role of Relayers

Relayers are the active participants that make Across feel instant. A relayer is an independent party, anyone with capital and the technical setup to run the necessary software, that monitors the protocol for new deposits and fulfills them by sending the requested funds to users on the destination chain. Crucially, relayers use their own capital to do this. When a relayer fills an intent, it is fronting the destination funds to the user before it has been reimbursed by the protocol. This is why the user experiences near-instant delivery: they are not waiting for any slow cross-chain message, only for a relayer to decide to act, which happens in seconds.

The relayer network is permissionless, meaning there is no gatekeeper deciding who may participate. Anyone can become a relayer and compete to fill transfers. This permissionless quality is central to the decentralization and resilience of the protocol. Because no single relayer is required for the system to function, the failure or withdrawal of any individual relayer does not interrupt service. If one relayer does not fill an intent, another will, and the competition among them ensures that users continue to receive fast, competitively priced transfers even as conditions change.

Relayers take on a specific, bounded form of risk. When a relayer fronts funds to a user, it is betting that the corresponding deposit on the source chain is valid and that it will be reimbursed during settlement. The protocol is designed so that this risk is manageable and well understood, and relayers price it into the fee they require to fill an intent. In effect, relayers are providing a short-term capital and timing service, and they are compensated for it through the relay fee. This market-based provisioning of liquidity is far more capital-efficient than locking large pools of idle assets, because relayer capital is recycled rapidly as transfers settle.

Cross-Chain Transfer Mechanism

The cross-chain transfer mechanism ties the pieces together into a coherent flow. The process begins when a user deposits funds into the Across smart contract on the origin chain along with the parameters of their intent. This deposit is observable on-chain, and relayers monitoring the network detect it immediately. A relayer then sends the requested tokens to the recipient on the destination chain, completing the user-facing portion of the transfer. From the user's perspective, the bridge is now finished: the funds have arrived.

Behind the scenes, the protocol records that a relayer has fulfilled a specific intent and is therefore owed reimbursement. The accounting for which relayer filled which deposit, and how much they are owed, is aggregated and periodically settled. Settlement draws on the protocol's pooled liquidity to repay relayers for the funds they fronted plus their earned fee. Because settlement is batched and verified rather than executed individually in real time, the protocol can afford to be deliberate and secure about it without slowing down the user experience at all.

This two-tier structure, fast fulfillment followed by deliberate settlement, is the heart of how Across achieves both speed and safety. The fast tier is optimized for the user and powered by relayer capital. The slow tier is optimized for correctness and security and powered by the protocol's verification system and unified liquidity. By keeping these tiers separate, Across avoids the trade-off that forces many bridges to choose between being fast and being secure.

Optimistic Verification

To reimburse relayers safely, Across must confirm that each claimed transfer actually happened as described. It does this through an optimistic verification model. In an optimistic system, claims about what occurred are assumed to be valid by default and are accepted unless they are challenged within a defined window. This approach is efficient because, in the overwhelming majority of cases, the claims are honest and no dispute is necessary, so the system does not need to perform expensive verification work for every single transfer.

The optimistic model relies on the presence of economically motivated watchers who can dispute incorrect claims. If a relayer or any party were to submit a false statement about which transfers occurred or how much should be repaid, that claim can be challenged during the verification window. A successful challenge prevents the invalid payout and penalizes the dishonest actor, while an unsuccessful or frivolous challenge penalizes the challenger. This balance of incentives makes honesty the rational strategy and dishonesty expensive, which keeps the system secure without requiring a trusted central authority to approve every transaction.

Optimistic verification is particularly well suited to a bridge because it allows the protocol to settle large volumes of transfers efficiently while maintaining strong guarantees against fraud. The verification process secures the settlement layer, where the real accounting and repayment happen, rather than gating the fast user-facing delivery. As a result, users enjoy immediate transfers while the protocol retains a rigorous, dispute-backed process for ensuring that every relayer reimbursement is legitimate.

Settlement and Relayer Repayment

Settlement is the stage at which relayers are repaid for the capital they fronted to users. After transfers have been recorded and the relevant claims have passed through the optimistic verification window without successful challenge, the protocol reimburses relayers from its pooled liquidity. This repayment includes both the principal the relayer advanced and the fee the relayer earned for providing the service. Because settlement is batched and verified, it can be conducted in a way that is both gas-efficient and secure.

The elegance of this arrangement is that it recycles capital continuously. A relayer fronts funds, gets reimbursed at settlement, and is then free to fill new intents with the same capital. This rapid recycling means that a relatively modest amount of relayer and protocol capital can support a very large volume of transfers over time, which is one reason Across is so capital-efficient compared to designs that require large amounts of locked, idle liquidity on every chain.

From the user's standpoint, settlement is entirely invisible. The user received their funds the moment a relayer filled their intent, and everything that follows, including verification and repayment, is the protocol's concern rather than the user's. This invisibility is intentional and reflects the core philosophy of Across: the complex machinery that makes fast, secure bridging possible should never intrude on the simplicity of the experience.

The Across Bridge

The Across Bridge is the user-facing product through which the protocol's capabilities are accessed. It presents a clean, minimal interface for moving assets between supported chains, and it is also available as infrastructure that other applications can embed directly into their own products. Whether used through its own application or as an integrated component inside a larger platform, the Across Bridge delivers the same core benefits: fast settlement, low fees, deep liquidity, and non-custodial security.

Bridging Assets Between Chains

Bridging assets with Across is designed to be effortless. A user connects a wallet, selects the chain they are moving funds from and the chain they want to move funds to, chooses the token and amount, and confirms the transaction. Once the deposit is confirmed on the origin chain, a relayer fulfills the request and the funds appear in the user's wallet on the destination chain, typically within a couple of seconds. There are no intermediate steps for the user to manage, no wrapped tokens to redeem, and no separate claim transaction to execute on the other side.

This simplicity holds across a wide range of transfer sizes. Small transfers are handled just as smoothly as large ones, and the protocol's deep, unified liquidity allows it to absorb large transfers without the slippage or failed transactions that can plague thinner bridges. For users accustomed to the friction of older bridging experiences, the directness of the Across Bridge is often striking: the funds simply arrive, reliably and quickly, regardless of which supported chains are involved.

Swapping and Bridging in One Step

Across goes beyond simple like-for-like transfers by supporting the ability to swap and bridge in a single action. A user can start with one token on the origin chain and receive a different token on the destination chain, with the conversion handled as part of the same flow. This means a person can, for example, move funds from one network to another and arrive holding exactly the asset they intend to use, rather than having to perform a separate swap once the bridge is complete.

Combining swapping and bridging in one step removes a major source of friction in multi-chain workflows. Without it, users frequently have to bridge an asset, wait, then navigate to a decentralized exchange on the destination chain to convert it into the token they actually want, paying additional fees and incurring additional risk at each stage. By collapsing these operations into a single intent, Across reduces both the number of transactions a user must sign and the cognitive overhead of coordinating them. The protocol determines the optimal path to deliver the desired output token, and the user experiences it as one seamless transfer.

Transfer Speed and Finality

Speed is one of the defining attributes of the Across Bridge. Because relayers front destination funds the moment a deposit is detected, the time between initiating a transfer and receiving funds is typically on the order of one to two seconds. This is dramatically faster than bridges that must wait for the canonical finality of underlying messaging systems, which can take many minutes or longer depending on the chains involved. For users, this means that bridging stops being a waiting game and becomes a near-instant action.

It is important to distinguish between the speed a user experiences and the finality the protocol relies on for settlement. The user receives funds almost immediately because a relayer has chosen to fulfill the intent using its own capital. The protocol, meanwhile, uses the more deliberate finality of the underlying chains and its verification process to settle relayer reimbursements safely. This separation lets Across offer instant user-facing speed without compromising on the rigor of its internal accounting. The fast experience is real, and the security guarantees behind it are equally real, because each is handled by the layer best suited to it.

Fees and Cost Structure

The fee structure of Across is built around the principle of keeping costs as low as possible while fairly compensating the parties who provide the service. When a user requests a transfer, they are quoted a fee that reflects the cost of fulfilling the intent. This fee compensates relayers for the capital they front and the timing risk they assume, and it contributes to the returns earned by liquidity providers who supply the protocol's settlement liquidity. The user sees the full cost upfront and pays exactly what they are quoted, with no hidden spreads layered into the exchange rate and no aggregator markup added on top.

Because relayers compete to fill intents, the fee a user pays is continuously pushed toward the true economic cost of the transfer. A relayer that demands too high a margin will simply be outbid by another relayer willing to accept less, and this competition acts as a persistent downward pressure on fees. The cost of a transfer also reflects underlying gas costs on the relevant chains and the size of the transfer, but the structural design of the marketplace ensures that users are not overcharged relative to the genuine cost of moving their funds. This transparent, competition-driven pricing is a core reason the Across Bridge is regarded as one of the most cost-effective ways to move value across chains.

Supported Chains and Networks

Across is built for a multi-chain world, and its value grows with the breadth of networks it connects. The protocol supports Ethereum mainnet alongside a wide and expanding set of Layer 2 rollups and alternative networks, allowing users to move freely among the ecosystems where activity is concentrated. The list of supported chains is continually extended as new networks gain traction, reflecting the protocol's role as connective tissue for the broader ecosystem.

Ethereum and Mainnet

Ethereum mainnet is the settlement anchor of the cross-chain world and a foundational network for Across. As the home of the deepest liquidity and the largest concentration of decentralized finance activity, Ethereum is both a common origin and a common destination for transfers. Across enables users to move funds onto Ethereum from faster, cheaper networks when they need access to mainnet liquidity or applications, and to move funds off Ethereum onto scaling networks when they want lower transaction costs. This bidirectional connectivity makes Ethereum a hub within the network of chains that Across serves.

Layer 2 and Scaling Networks

The bulk of the chains Across connects are Layer 2 networks and other scaling solutions that extend Ethereum's capacity while reducing transaction costs. The protocol supports a broad collection of these networks, including major rollups such as Arbitrum, Optimism, and Base, as well as Polygon and a wide range of additional environments like zkSync, Linea, Blast, Mode, Zora, World Chain, Ink, Soneium, Unichain, Lens, and Lisk, among others. By connecting these networks to one another and to Ethereum, Across allows users to take advantage of low-cost execution on Layer 2s while retaining the ability to move value wherever it is needed.

This dense web of Layer 2 connectivity is particularly valuable because activity in decentralized finance has increasingly migrated to these networks in search of lower fees and faster transactions. A user might hold assets on one rollup, discover an opportunity on another, and need to move quickly to capture it. Across makes that movement near-instant and inexpensive, turning the fragmented landscape of rollups into something that feels closer to a single, unified environment. For many users, the Across Bridge is the primary means by which they navigate the Layer 2 ecosystem.

Ecosystem Expansion

The set of networks Across supports is not static. As new chains launch and gain users, the protocol extends to include them, often becoming an early and important bridging option for emerging ecosystems. This expansion reflects a deliberate strategy of meeting users wherever they are and ensuring that new networks are not isolated from the liquidity and activity of the broader ecosystem. By integrating emerging chains alongside established ones, Across reinforces its position as a comprehensive interoperability layer rather than a bridge tied to any single set of networks.

Expansion also benefits the networks themselves. A new chain that is connected to Across gains immediate access to a large base of users and to the liquidity that flows through the protocol, lowering the barrier for people to try the network and for applications to attract users from elsewhere. In this way, Across functions not only as a tool for individual users but as infrastructure that helps the entire multi-chain ecosystem grow more interconnected over time.

Supported Assets and Tokens

Across supports the transfer of a range of widely used digital assets across the chains it connects. The focus is on the tokens that see the most demand for cross-chain movement, including major stablecoins and blue-chip assets that form the backbone of decentralized finance activity. By concentrating liquidity on the assets people most want to move, the protocol is able to offer deep liquidity and reliable, low-slippage transfers even for large amounts.

Stablecoins are among the most frequently bridged assets, because they serve as the primary medium of exchange and unit of account across the ecosystem. Users routinely move stablecoins between chains to access yield opportunities, to provide liquidity, to settle obligations, or simply to position funds where they intend to transact. Across handles these stablecoin transfers quickly and cheaply, which is one reason it is so heavily used as settlement infrastructure by other applications that need to route stable value between networks.

Beyond stablecoins, Across supports the transfer of leading assets that users hold for exposure, collateral, or utility within applications. The ability to swap and bridge in a single step further broadens the practical range of what users can accomplish, since a user can begin with one asset and end with another on the destination chain. Taken together, the protocol's asset support is designed to cover the most important flows of value across chains while maintaining the depth of liquidity necessary to keep those flows fast and inexpensive.

Key Features of Across Protocol

The reputation of Across rests on a set of features that work together to deliver a superior bridging experience. These features are not isolated capabilities but interdependent aspects of a single coherent design. Speed, low fees, capital efficiency, non-custodial security, and decentralization reinforce one another, and it is their combination that explains why Across has become a default choice for both individual users and the applications that build on top of it.

Fast Settlement by Default

Fast settlement is the most immediately noticeable feature of the Across Bridge. Transfers typically complete in roughly one to two seconds, which transforms bridging from something users dread into something they barely notice. This speed is not an optional premium tier or a best-case scenario; it is the normal behavior of the protocol, made possible by relayers who front funds the instant a deposit is detected. By making speed the default rather than the exception, Across removes one of the largest sources of friction and anxiety in cross-chain activity.

Low Fees

Low fees are a structural property of the protocol rather than a temporary promotion. Because relayers compete to fill intents, the fees users pay are continuously driven toward the genuine economic cost of the transfer. There are no aggregator markups and no hidden spreads buried in the exchange rate, so the price users are quoted is the price they pay. For users moving funds frequently or in large amounts, these savings accumulate meaningfully, and for applications routing large volumes through the protocol, low fees are a decisive advantage.

Capital Efficiency

Capital efficiency is one of the more technical but consequential features of Across. Because relayer capital is recycled rapidly as transfers settle, the protocol can support a very large volume of transfers with a comparatively modest amount of liquidity. This contrasts with designs that require large pools of idle assets locked on every supported chain, which tie up capital inefficiently and create their own risks. The efficient use of capital lowers the cost of providing the service, and those savings flow through to users in the form of lower fees and to liquidity providers in the form of better returns.

Non-Custodial Security

Non-custodial security means that users retain control of their funds and are never exposed to a centralized custodian during a transfer. The Across smart contracts are designed so that funds move according to the rules of the protocol rather than at the discretion of any operator. There is no privileged party that can freeze, seize, or redirect user assets. This property is fundamental to the safety of the bridge, because it eliminates the category of risk in which a custodian is hacked, becomes insolvent, or acts maliciously. Users interact with code and economic incentives, not with a trusted intermediary.

Decentralized Relayer Network

The decentralized relayer network is what gives Across its resilience and its competitive pricing. Because the network is permissionless, anyone can participate as a relayer, and no single relayer is essential to the operation of the protocol. This eliminates single points of failure and ensures that the system continues to function even if individual relayers go offline. The competition among relayers is also the engine that drives down fees and delivery times, since each relayer is incentivized to be faster and more efficient than its peers in order to capture the fees associated with filling intents.

The ACX Token and Tokenomics

ACX is the native token of Across Protocol and the instrument through which the community governs and helps sustain the network. The token is designed to align the long-term interests of users, liquidity providers, relayers, and the broader community, and it sits at the center of the protocol's decentralized governance. Understanding ACX requires looking at its utility within the system, the governance rights it confers, and the way it is distributed across stakeholders.

Token Utility

The primary utility of ACX lies in governance and in coordinating the incentives that keep the protocol fast and liquid. Holders of the token are empowered to participate in decisions about how the protocol evolves, and the token is used to reward the participants whose contributions make the network function. Liquidity providers who supply the capital that backs settlement and relayers who provide the fast fulfillment of intents can be incentivized through token-based rewards, helping ensure that the protocol always has the liquidity and relay capacity it needs to serve users reliably.

By tying these incentives to the native token, Across creates a feedback loop in which the people who support the network share in its success and have a stake in its continued health. This alignment is important for a protocol that aspires to be durable, permissionless infrastructure rather than a venture controlled by a single company. The token gives the community both the means and the motivation to steward the protocol responsibly over the long term.

Governance Rights

ACX confers governance rights that allow holders to shape the direction of the protocol. Through the governance process, the community can propose and decide on changes to protocol parameters, the addition of new chains and assets, the structure of incentives, and other matters that determine how Across operates. This places meaningful control in the hands of the people who use and support the protocol rather than concentrating it in a small group, and it reflects the broader commitment to decentralization that runs throughout the project.

Governance is not merely symbolic. The decisions made through it have real consequences for how the protocol functions, how its resources are allocated, and how it responds to a changing environment. By giving token holders a genuine voice in these decisions, Across ensures that its evolution is guided by its community and that the protocol can adapt over time without depending on any single centralized authority.

Token Distribution

The distribution of ACX is designed to place the token in the hands of the community and the participants who contribute to the protocol's growth. Rather than concentrating ownership narrowly, the distribution emphasizes broad participation, rewarding users, liquidity providers, and others who help the network thrive. This approach supports the goal of decentralized governance, because a widely held token allows decision-making power to be genuinely distributed across the community rather than dominated by a small number of holders.

A thoughtful distribution also helps build a committed base of stakeholders who are invested in the protocol's long-term success. When the people who use and support Across also share in its governance and its rewards, they have a reason to participate constructively in its development. This alignment between ownership and contribution is central to the design of the token and to the protocol's aspiration to function as community-owned public infrastructure.

Liquidity and the Hub Pool

Liquidity is the lifeblood of any bridge, and Across is built around a model that uses liquidity efficiently while keeping it secure. Rather than scattering isolated pools across every chain, the protocol organizes liquidity in a way that allows it to back transfers throughout the network and to reimburse relayers reliably at settlement. This structure is a major reason the protocol can offer deep liquidity, support large transfers, and maintain low fees at the same time.

Unified Liquidity Model

The unified liquidity model is one of the most important architectural choices in Across. Instead of requiring separate, fragmented liquidity to be locked on each chain, the protocol centralizes the accounting of liquidity so that it can be deployed wherever it is needed to settle transfers. This unification means that liquidity providers contribute to a shared resource that supports the entire network rather than committing capital to a single isolated route. The result is far greater capital efficiency and deeper effective liquidity for every supported chain.

Unified liquidity also improves the user experience directly. Because the protocol can draw on a common base of liquidity to settle relayer reimbursements, it can support large transfers across many routes without the thin, easily exhausted pools that limit fragmented designs. For users, this translates into reliable transfers that do not fail or suffer excessive slippage even when moving significant amounts, and for the protocol, it translates into a more robust and scalable system.

Liquidity Provider Incentives

Liquidity providers are the participants who supply the capital that backs settlement, and they are compensated for doing so. By contributing liquidity to the protocol, they enable relayers to be reimbursed and the system to function smoothly, and in return they earn a share of the fees generated by transfers along with potential token-based incentives. This creates an attractive opportunity for capital that wishes to earn yield while supporting essential infrastructure.

The incentive structure for liquidity providers is designed to be sustainable and aligned with the health of the protocol. Because liquidity is used efficiently and recycled rapidly through the settlement process, the returns to liquidity providers can be generated from genuine economic activity rather than from unsustainable subsidies. This alignment helps ensure that the protocol can attract and retain the liquidity it needs to keep transfers fast, deep, and reliable as volume grows.

Security and Reliability

Security is the foundation on which the rest of the protocol stands, because a bridge that cannot be trusted to safeguard funds has no value regardless of how fast or cheap it is. Across has been engineered from the ground up to minimize risk, and its track record reflects the success of that approach. The protocol combines an optimistic security model, a permissionless architecture without privileged control, and a history of careful auditing to provide users and integrators with strong assurances about the safety of their funds.

Optimistic Security Model

The optimistic security model is the core of how Across protects its settlement layer. Under this model, claims about which transfers occurred are accepted by default but remain open to challenge during a verification window, with economic incentives ensuring that dishonest claims are caught and penalized. This design avoids the need for a trusted central verifier while still providing strong protection against fraud, because any attempt to claim funds dishonestly can be disputed and punished, making honest behavior the economically rational choice.

A key strength of this model is that it secures the protocol without introducing the fragile trust assumptions that have led to failures in other bridges. There is no small set of signers whose compromise would jeopardize user funds, and there is no central operator who must be trusted to behave correctly. Instead, the security of the system rests on transparent rules and economic incentives that anyone can verify and that align the interests of participants with the integrity of the protocol.

Audits and Track Record

Across has undergone extensive security review, and its smart contracts have been examined by security professionals to identify and address potential vulnerabilities before they can be exploited. This commitment to auditing reflects an understanding that bridges are high-value targets and that rigorous review is essential to protecting users. Auditing is treated not as a one-time event but as an ongoing discipline that accompanies the protocol's development.

The most compelling evidence of the protocol's security is its track record. Across has facilitated tens of billions of dollars in cumulative transfer volume and has never been hacked. In an environment where bridge exploits have repeatedly resulted in enormous losses across the industry, this unblemished record is a powerful testament to the soundness of the protocol's design and the diligence of its security practices. For users and integrators evaluating where to entrust their funds, a long history of moving enormous value without an exploit is among the strongest signals available.

Risk Management

Beyond its core security model and auditing, Across incorporates a thoughtful approach to risk management throughout its design. The separation of fast user-facing delivery from deliberate, verified settlement confines risk to bounded, well-understood forms, such as the short-term capital and timing risk that relayers knowingly assume and price into their fees. The permissionless and decentralized structure of the relayer network removes single points of failure, and the absence of privileged control over user funds eliminates an entire category of custodial risk.

This layered approach to risk means that the failure of any single component does not cascade into a systemic failure of the protocol. Users continue to receive their funds even if individual relayers withdraw, the settlement layer remains protected by economic incentives even under adversarial conditions, and the non-custodial design ensures that funds are never at the mercy of a trusted intermediary. Reliability, in this sense, is not an accident but the deliberate outcome of an architecture designed to degrade gracefully and to keep user funds safe under a wide range of circumstances.

Across for Builders and Integrations

While many people interact with Across directly, a great deal of its volume flows through other applications that have integrated the protocol as their bridging layer. Across is designed to be embedded, allowing builders to offer fast, cheap, secure cross-chain transfers to their own users without having to construct bridging infrastructure themselves. This makes the protocol not only a consumer product but a foundational piece of infrastructure for the broader ecosystem of applications.

Embedded Bridging

Embedded bridging refers to the practice of integrating Across directly into another application so that users can bridge without leaving that application. Through a single integration, a builder can add support for a wide range of chains and offer their users the same fast settlement and low fees that the Across Bridge provides natively. This spares the builder the enormous effort and risk of creating and maintaining their own bridge, and it spares their users the friction of switching to a separate tool to move funds.

The appeal of embedded bridging is that it keeps users within a single, coherent experience. Rather than sending a user away to a separate bridge and hoping they return, an application can let the user accomplish everything in one place. This improves retention and satisfaction for the application while extending the reach of Across to users who may never interact with the protocol's own interface. The single-integration, many-chains model is a major reason Across has become a preferred bridging layer for builders.

Notable Integrations

Across has been integrated by a number of prominent applications that rely on it to power crosschain transfers for their users. Among the most notable is the integration with Uniswap, which brought native crosschain transfers directly into the Uniswap experience. By embedding Across, Uniswap was able to add bridging across a vast majority of the chains it needed, with fast settlement and low fees, through a single integration rather than stitching together multiple providers. This kind of integration illustrates the value proposition of Across for builders: comprehensive chain coverage and a strong user experience delivered through one clean connection.

Integrations like these reflect the trust that leading teams place in the protocol. When some of the largest names in the ecosystem choose to route their users' funds through Across, they are making a statement about its reliability, its security record, and the quality of the experience it provides. Each integration also reinforces the network effects of the protocol, as more volume flows through it, more liquidity is attracted to it, and the experience improves for everyone who uses it, whether directly or through an integrated application.

Governance and the Across DAO

Across is governed as a decentralized protocol through the Across DAO, the community body that holds authority over the direction of the project. The DAO embodies the principle that critical infrastructure should be controlled by its community rather than by a single company, and it provides the mechanism through which token holders exercise the governance rights conferred by ACX. Through the DAO, the community can deliberate on proposals, allocate resources, and steer the evolution of the protocol.

The scope of governance is broad. The community can decide on the addition of new chains and assets, adjustments to incentive structures, the allocation of treasury resources, and changes to the parameters that govern how the protocol operates. By placing these decisions in the hands of token holders, the DAO ensures that the protocol remains responsive to the needs of its users and adaptable to a rapidly changing environment, without ceding control to a centralized authority that might prioritize its own interests over those of the community.

Decentralized governance also strengthens the protocol's resilience and credibility. Because no single entity can unilaterally alter the rules or seize control, users and integrators can rely on the protocol behaving predictably and in accordance with the wishes of its broad community of stakeholders. This is especially important for infrastructure that other applications build upon, since those applications need confidence that the foundation they depend on will not be changed arbitrarily. The Across DAO provides that confidence by distributing authority and binding the protocol's direction to a transparent, community-driven process.

Across Compared to Other Bridges

Comparing Across to other bridges highlights the ways in which its design choices translate into practical advantages. The most fundamental distinction is architectural. Many bridges rely on lock-and-mint mechanisms that create wrapped tokens, or on slow canonical messaging that forces users to wait for finality before funds arrive. Across instead uses an intent-based model in which relayers deliver funds immediately and settlement happens separately, giving users near-instant transfers of the assets they actually want rather than synthetic representations they must later redeem.

On speed, the contrast is stark. Where some bridges require many minutes or longer to complete a transfer, Across typically delivers funds in one to two seconds. On cost, the competitive relayer marketplace pushes fees toward their true economic level and avoids the aggregator markups and hidden spreads that inflate the cost of other bridges. On security, the optimistic model and the absence of privileged multisig control remove the trust assumptions that have led to some of the largest exploits in the history of cross-chain infrastructure, and the protocol's record of moving enormous volume without a hack stands in sharp contrast to the troubled security history of the category as a whole.

There is also a difference in capital efficiency and liquidity. Bridges that depend on large locked pools on every chain tie up capital inefficiently and often struggle to support large transfers across less popular routes. The unified liquidity model and rapid capital recycling of Across allow it to provide deep, reliable liquidity with far less idle capital, which benefits users through better pricing and integrators through more dependable execution. Taken together, these comparisons explain why Across is so frequently selected, both by individual users and by sophisticated teams, as the bridging layer they prefer to rely on.

Use Cases and Adoption

The use cases for Across span the full range of activity in a multi-chain ecosystem. The most common is the straightforward movement of funds between chains, whether a user is relocating assets to access lower fees on a Layer 2, moving liquidity to capture an opportunity on another network, or consolidating holdings onto a preferred chain. For these everyday transfers, the speed and low cost of the Across Bridge make it a natural default, and its reliability across transfer sizes means users can depend on it whether they are moving a small amount or a substantial sum.

Beyond individual transfers, Across serves as infrastructure for applications that need to move value on behalf of their users. Decentralized exchanges, wallets, and other platforms integrate the protocol to offer crosschain functionality natively, routing potentially enormous volumes through it. In these contexts, Across is less a destination that users visit and more an invisible engine that powers the crosschain features of the products people already use. This dual role, as both a direct product and an embedded layer, has driven adoption across a wide spectrum of the ecosystem.

The scale of that adoption is considerable. Across has moved tens of billions of dollars in cumulative volume and is trusted by millions of users, ranging from individuals making their first bridge transaction to institutions moving large sums. It powers crosschain transfers for many of the most prominent applications in the space, and its average transfer speed and security record have made it a benchmark against which other bridges are measured. This breadth of adoption is both a result of the protocol's design and a reinforcement of it, as growing volume deepens liquidity and improves the experience for everyone who relies on it.

Frequently Asked Questions

What is Across Protocol?

Across Protocol is an intent-based cross-chain bridge that lets users move tokens between blockchains quickly, cheaply, and without custodial risk. A user expresses an intent to receive a specific asset on a destination chain, and a competitive network of relayers fulfills that intent almost instantly using their own capital, while the protocol settles the underlying accounting afterward through a secure verification process.

Is the Across Bridge safe to use?

Across is a non-custodial bridge, meaning users retain control of their funds and are not exposed to a centralized custodian during a transfer. It is secured by an optimistic verification model and a permissionless relayer network with no privileged multisig control over user assets, and it has facilitated tens of billions of dollars in volume without ever being hacked.

How fast is Across Protocol?

Most transfers on Across complete in roughly one to two seconds. This speed is possible because relayers front the destination funds to users the moment a deposit is detected on the origin chain, rather than waiting for the slower finality of canonical bridging systems. Fast settlement is the default behavior of the protocol rather than a premium option.

What is the ACX token used for?

ACX is the native governance token of Across Protocol. It is used to govern the protocol through the Across DAO, giving holders a voice in decisions about chains, assets, incentives, and parameters, and it is used to incentivize the liquidity providers and relayers whose contributions keep the bridge fast, deep, and reliable.

Which chains does Across support?

Across supports Ethereum mainnet alongside a wide and growing set of Layer 2 and alternative networks, including Arbitrum, Optimism, Base, Polygon, zkSync, Linea, Blast, Mode, Zora, World Chain, and many others. The set of supported networks is continually expanded as new chains gain adoption.

Does Across use wrapped tokens?

The user-facing flow of Across does not rely on wrapped tokens. Relayers deliver the asset the user actually wants on the destination chain, so users end up holding a natively recognized token rather than a synthetic representation that depends on the solvency of a bridge contract and must later be redeemed.

Can I swap and bridge at the same time?

Yes. Across supports swapping and bridging in a single action, allowing a user to start with one token on the origin chain and receive a different token on the destination chain. This collapses what would otherwise be multiple transactions into one seamless transfer, reducing both cost and complexity.

Conclusion

Across Protocol represents a mature answer to one of the most persistent challenges in decentralized finance: how to move value between an ever-growing number of blockchains quickly, cheaply, and safely. By reimagining bridging as a marketplace for fulfilling user intents, the protocol delivers an experience that feels instant while preserving the trustlessness and security that the ecosystem demands. The separation of fast relayer-powered delivery from deliberate, verified settlement is an elegant solution that resolves the long-standing tension between speed and safety.

The strengths of the protocol reinforce one another. Fast settlement, low fees, capital efficiency, non-custodial security, and a decentralized relayer network are not independent features but facets of a single, coherent design, and together they explain why the Across Bridge has earned the trust of millions of users and many of the leading applications in the industry. Its record of moving tens of billions of dollars without an exploit stands as compelling evidence that this design works under real-world conditions and at significant scale.

As the ecosystem continues to fragment across new chains and the need for seamless interoperability grows, the role of infrastructure like Across only becomes more important. Governed by its community through the Across DAO and powered by the ACX token, the protocol is positioned to keep adapting and expanding as the multi-chain world evolves. For anyone seeking to understand how value moves across chains, Across Protocol stands as a leading example of how thoughtful design can make a complex problem feel simple, turning the fragmented landscape of blockchains into something that finally behaves like a connected whole.