The cross protocol is a novel bridging method that combines optimistic oracles, bound relays, and unilateral liquidity pools to provide decentralized instant transactions from the aggregation chain to the Ethereum mainnet.

Across collects liquidity pools of ERC20 tokens on Ethereum to facilitate rapid withdrawal of token deposits on Layer 2 (L2) networks such as Optimism and Arbitrum. Deposits on Layer 2 are one-way, sent to pools on Ethereum by slow local bridges of the L2 network, repaying liquidity providers. This can be thought of as liquidity providers making short-term loans on Ethereum backed by layer 2 deposits.

To bridge the token, the relayer publishes a deposit along with L2 deposit details, allowing withdrawals from Ethereum’s liquidity pool after a short challenge period. Relayers can also advance funds to depositors and receive compensation themselves from the liquidity pool after the challenge period ends. UMA's oracle mechanism allows anyone to dispute an invalid relay during the challenge period, and to demand a deposit from the relayer if the relay is incorrect.

Depositors pay liquidity providers for liquidity on Ethereum based on pool utilization. Alternatively, they can also provide a fee to incentivize relayers to verify their deposits, or they can relay tokens themselves.

Connect Wallet

Select a network and click button ‘Connect Wallet‘

Swap

Then select asset and the network of destination wallet, and input the amount and click button ‘Send‘

Pool

Select a pool and input amount, then click button ‘Add Liquidity‘

The cross protocol is a novel bridging method that combines optimistic oracles, bound relays, and unilateral liquidity pools to provide decentralized instant transactions from the aggregation chain to the Ethereum mainnet.

Across collects liquidity pools of ERC20 tokens on Ethereum to facilitate rapid withdrawal of token deposits on Layer 2 (L2) networks such as Optimism and Arbitrum. Deposits on Layer 2 are one-way, sent to pools on Ethereum by slow local bridges of the L2 network, repaying liquidity providers. This can be thought of as liquidity providers making short-term loans on Ethereum backed by layer 2 deposits.

To bridge the token, the relayer publishes a deposit along with L2 deposit details, allowing withdrawals from Ethereum’s liquidity pool after a short challenge period. Relayers can also advance funds to depositors and receive compensation themselves from the liquidity pool after the challenge period ends. UMA's oracle mechanism allows anyone to dispute an invalid relay during the challenge period, and to demand a deposit from the relayer if the relay is incorrect.

Depositors pay liquidity providers for liquidity on Ethereum based on pool utilization. Alternatively, they can also provide a fee to incentivize relayers to verify their deposits, or they can relay tokens themselves.

Connect Wallet

Select a network and click button ‘Connect Wallet‘

Swap

Then select asset and the network of destination wallet, and input the amount and click button ‘Send‘

Pool

Select a pool and input amount, then click button ‘Add Liquidity‘