Across is a cross-chain bridge with optimistic rollup design that connect Ethereum, Polygon, Optimism and Arbitrum.

Across is an optimistic insured bridge that relies on a decentralized group of relayers to fulfill user deposit requests from EVM to EVM networks. Relayer funds are insured by liquidity providers in a single pool on Ethereum and refunds are processed via the UMA Optimistic Oracle.

Designed by the engineers who built UMA, Across was the result of approaching bridging not only as a technical concern but as a financial engineering concern.