System Actors and Inventory Context

• Users: Swap between 0xUSD and supported stablecoins; optionally interact with s0xUSD (ERC-4626 wrapper on 0xUSD).

• Allocators: Permissioned market-makers with a line of credit (ceiling, dailyCap) to mint 0xUSD, warehouse it as reservedZeroX, and manage per-asset pockets that deploy supported stablecoins into external strategies (Aave, Maker DSR/sDAI, T-bill wrappers, Curve pools, etc.).

• UCE (the engine): The settlement hub. Holds on-hand 0xUSD and on-hand underlyings (reserve buffer) and routes to pockets via allowances. Updates the dynamic redemption rate and performs debt scaling on 0xUSD → underlying conversions.

• Treasury: Receives allocator borrow fees (assessed on allocator repay).