pUSD
A collateral-backed stablecoin, run by a separate engine.
pUSD is a stablecoin minted against collateral, managed by a StableEngine that is separate from
the lending markets. Borrowing USDG from a market and minting pUSD are different actions with
different risk.
Troves
A position in the stable engine is a trove: collateral in, pUSD out, per collateral asset.
| Mint | Deposit collateral, mint pUSD up to the collateral's limit |
| Repay | Burn pUSD to reduce the debt |
| Liquidation | A trove past its ratio can be liquidated, as in the markets |
| Redemption | pUSD can be redeemed against troves |
Global parameters
| Minimum debt | The smallest trove allowed, so dust positions cannot be opened |
| Total debt ceiling | The most pUSD that may exist |
| Fee recipient | Where fees are sent |
Per-collateral parameters — ratios, ceilings, fees — are set per asset.
Bad debt
The engine tracks bad debt per collateral, and it can be covered explicitly by the owner rather than silently socialised.
Two engines have existed
Worth knowing if you are reading chain history. StableEngine is not a proxy, so fixing it meant
deploying a new one — and the old instance kept its state. The retired engine has been wound down:
its troves are closed, its MINTER_ROLE on pUSD has been revoked, and total pUSD supply now
reflects the live engine alone.
If you find an older engine address in an old artifact, it is not the one in use.
Status
pUSD is deployed and functional on testnet but is not the focus of the protocol today. The lending markets are.