Lead paragraph
Across Protocol is an intent-based bridge launched in 2022, designed for fast, capital-efficient transfers between Ethereum and layer-2 networks. Rather than traditional liquidity pools, it uses a competitive relayer system and UMA’s optimistic verification to settle transactions. The protocol powers bridge flows for Uniswap and Coinbase Wallet, and today spans 10 chains with a total value locked of about $21 million (DeFiLlama, as of 2026-07-15). Audited by OpenZeppelin, Mixbytes, and Code4rena, Across has recorded no major security incidents as of 2026.
What it is
Across Protocol is a bridge focused on minimizing transfer times and fees between Ethereum and its major rollups. It avoids the capital inefficiencies of lock-and-mint designs by relying on relayers who compete to fulfill user intents. Users request a destination-side payout, relayers front the funds instantly, and UMA’s optimistic oracle later verifies the transfer. This allows for transfers from L2 to L1 in under 5 minutes and L2-to-L2 swaps in seconds, depending on relayer competition. Governed by the Across DAO and the ACX token, the protocol has become a critical infrastructure piece for wallets and dApps seeking fast bridging without slippage.
How it works
When a user initiates a transfer, they submit an intent specifying source chain, asset, amount, and destination chain. Relay nodes scan these intents and bid to fill them by sending the desired token on the destination chain from their own inventory. The first relayer to provide valid pre-confirmation of the fill wins the order. The user receives funds almost instantly, while the relayer takes on the risk of slow settlement.
Settlement relies on UMA’s optimistic oracle. After the transfer, the oracle verifies the source-chain deposit. If no dispute is raised within a challenge period, the relayer is reimbursed from a pool of funds locked in Across contracts on the source chain. Relayers earn a spread based on the difference between the submitted amount and the verified amount, incentivizing fair pricing. Contracts on each supported chain handle escrow, relayer management, and oracle integration. The system uses batching and gas-efficient proofs to keep overhead low. No wrapped tokens are minted; users receive native assets on the destination.
Key numbers
Across Protocol holds about $21 million in TVL (DeFiLlama, as of 2026-07-15) across 10 chains: Ethereum, Arbitrum, Optimism, Base, Polygon, zkSync, Linea, Blast, Mode, and Scroll. The protocol launched in 2022 and has completed three audits—by OpenZeppelin, Mixbytes, and Code4rena. No security incidents have been publicly reported. ACX is the native governance token.
Security and audits
Across has undergone audits with OpenZeppelin, Mixbytes, and Code4rena, all completed before mainnet launch. No exploitable vulnerabilities from these reports remain unfixed publicly. The protocol’s security model leans heavily on UMA’s optimistic oracle, which has been live since 2020 and has a strong track record. Disputes are handled through UMA’s data verification mechanism, adding a layer of economic security.
Smart contracts are upgradable via the Across DAO, though the exact governance delay and multisig structure have not been detailed in public documentation. The relayer network introduces a different risk surface: relayers hold user funds temporarily and could fail to deliver, though economic incentives align them to act honestly. To date, no such event has occurred. The intent-based design is still maturing; while no major exploits have hit Across, edge cases around relayer liquidity shortages during extreme market volatility could strain the system.
Strengths
1. Fast L2 transfers without slippage. Relayers compete to fill orders instantly, resulting in transfers that often complete in under 30 seconds between L2s. This speed is a key reason for integration by Uniswap and Coinbase Wallet.
2. Capital-efficient design. Unlike bridges that require large locked liquidity pools on each chain, Across relayers provide just-in-time liquidity. This avoids idle capital and keeps fees low for users.
3. Strong audit and security record. With three credible audits and no incidents since launch, the protocol has a cleaner history than many bridges. The reliance on UMA’s battle-tested oracle further reinforces security.
Weaknesses and risks
1. Modest TVL limits capacity. At about $21 million, large transfers (e.g., over $1 million) may face delays or higher fees if relayers lack sufficient inventory. Competitors with deeper liquidity can handle larger volumes.
2. Dependency on UMA oracle. Any critical vulnerability in UMA’s optimistic verification would directly compromise Across. While UMA is audited, this coupling creates a shared risk surface.
3. Relayer centralization potential. Though permissionless in theory, high capital requirements and MEV-like competition could lead to a few dominant relayers, increasing censorship or outage risks during network congestion.
How it compares
Across competes directly with deBridge Finance deBridge Finance, which also uses an intent-based model but relies on market makers and a separate messaging protocol. Across holds more TVL (~$21M vs. deBridge's ~$2M, DeFiLlama as of 2026-07-15) and supports a similar number of chains (10 vs. 10), though deBridge includes Solana, giving it cross-ecosystem reach that Across lacks for non-EVM networks. Across’s use of UMA’s optimistic oracle differs from deBridge’s multi-validator approach, appealing to those who prefer a well-established verification system with economic guarantees.
Among broader DeFi peers, Across’s TVL is dwarfed by giants like Aave Aave ($14.2B) or Lido Lido ($17.3B), but those are lending and staking protocols, not bridges. In the bridge category, Across’s ~$21M TVL puts it in the lower-mid tier, behind market leaders like Stargate or Wormhole (not listed among direct peers). However, its focused L2-first approach and zero-exploit record differentiate it from bridges that have suffered high-profile hacks.
Verdict
Across Protocol offers a fast, well-audited bridge suited for users moving funds between Ethereum and popular rollups. The intent-based design keeps fees low and speeds high, and its integration with major wallets validates its real-world utility. However, the $21M TVL caps throughput, and the system’s reliance on UMA adds a single point of dependency. For routine L2 transfers under six figures, Across is a reliable option. Large, time-sensitive movements or cross-ecosystem swaps may require deeper liquidity bridges. Rating: 7.8/10.