According to MakerDAO’s announcement, the new bridge will drastically reduce the time needed for withdrawing tokens from Optimism’s layer 2 to layer 1. While the platform’s current design allows tokens to be transferred from L1 to L2 near-instantly, withdrawing tokens to L1 requires a 7-day waiting period to allow for potential fraud proofs.
The new bridge will enable near-instant withdrawals by swapping L2 tokens for oDai on L2, then swapping it for L1 Dai. The L2 Dai is then swapped back to the L1 token, enabling users to withdraw it without the long wait times.
When launched, the Optimism Dai bridge will have the potential to serve as the go-to service for exiting L2, making MakerDAO the primary off-ramp for Optimism.
The project will be split into two deliverables—the Optimism Dai bridge and Fast Withdrawals. While MakerDAO said that fast withdrawal won’t be launched until Q3 or Q4 2021, the Optimism Dai Bridge is set to launch “soon.”
The delay in launching is mostly caused by the mechanism behind the Fast Withdrawals, which requires an automated market maker (AMM), such as Uniswap, to exist both on L1 and L2. Sam McPherson, the head of smart contracts at MakerDAO, explained that some AMM might support this feature directly in their UI.