Here is the full registry of OUSD smart contracts that have been deployed to the Ethereum mainnet.
The main ERC20 address for Origin Dollar (OUSD) is:
Most of our contracts are upgradable via a well-known proxy wrapper and an implementation contract. The Vault is split into VaultAdmin and VaultCore to work around the maximum contract size limit on Ethereum
Flipper is a gas-optimized way for users to swap in and out of OUSD at a fixed 1:1 rate with other stablecoins. This contract may become empty on one side (e.g., contain 0 OUSD balance), and thus sometimes provides limited swap routes.