Across Protocol

Across Protocol is an intent-based cross-chain bridge that routes transfers between Ethereum, Solana, and multiple Layer 2 networks. Rather than waiting on canonical bridge finality or relying on lock-and-mint wrapped assets, independent relayers fulfill user orders upfront on the destination chain and claim repayment later. By October 2026, the bridge had processed over $40 billion in cumulative volume across 5 million users.

Founders and funding

Across was conceived and supported by Risk Labs, the foundation team behind the UMA optimistic oracle. The project raised $10 million in a private token sale in November 2022 from investors including Hack VC, Placeholder, and Blockchain Capital at a $200 million valuation. In March 2025, Across raised an additional $41 million round led by Paradigm, with participation from Bain Capital Crypto, Coinbase Ventures, and Multicoin Capital. In September 2026, governance announced operational restructuring under Across, Inc. alongside a transition plan for the ACX token.

How transfers and settlement work

Transfers rely on an intents architecture combined with single-sided liquidity pools on Ethereum mainnet and UMA optimistic verification. When a user submits a bridge request, competing third-party relayers verify the intent and provide short-term capital by releasing native tokens on the target network immediately. Relayers are repaid after UMA optimistic oracles verify that transfers were completed correctly. The protocol connects networks including Ethereum, Base, Arbitrum, Optimism, Polygon, Solana, Linea, Zora, Unichain, Hyperliquid, and Avalanche.

Fees and access

The bridge operates on a non-custodial, permissionless basis without identity verification (KYC). Pricing is quoted dynamically per transaction without fixed protocol markups: users pay a network execution fee alongside a variable relayer fee determined by capital requirements and gas costs on the destination network. Large stablecoin transfers can also access locked-rate execution, including routing up to $50 million via Paxos Labs Transit integration.

Security track record and risks

Across was originally audited by OpenZeppelin in 2021 ahead of its public mainnet release. In July 2026, an exploit occurred when an attacker targeted off-chain event-parsing software used by Solana relayers. The attacker spoofed transaction event logs, tricking Risk Labs relayers into paying out approximately $3.35 million in relayer capital. Core smart contracts on Ethereum and Solana were not breached, and no user balances were affected. Primary risks include reliance on off-chain relayer infrastructure and optimistic verification disputes.