starUSD

starUSD is the USD stablecoin issued by Lucent. Its supply changes only when Lucent debt changes.

Users cannot mint starUSD directly. They open or adjust a Trove, and protocol contracts mint only after all collateral, oracle, ratio, receiver, trustline, and branch-status checks pass.

Mint Authority

StarUsdController holds the starUSD mint authority through the Stellar Asset Contract. It accepts mint requests only from protocol modules registered in CollateralRegistry.

The intended issuer setup is:

Flag	Setting
`AUTH_REQUIRED_FLAG`	Off, so holding starUSD does not require a whitelist.
`AUTH_REVOCABLE_FLAG`	Off, so the issuer cannot freeze user balances.
`AUTH_CLAWBACK_ENABLED_FLAG`	Off, so the issuer cannot claw back user balances.
`AUTH_IMMUTABLE_FLAG`	On, so the flag policy cannot be changed later.

After setup, the StarUSDController contract is set as the SAC admin, the admin relationship is verified, and the issuer account is locked forever.

Mint Flow

The user deposits XLM collateral.
The protocol records Trove debt.
The protocol locks the collateral.
StarUsdController mints starUSD.
Minted starUSD is sent to the borrower or selected receiver.

Burn and Removal Flow

When debt is reduced, repaid, redeemed, or liquidated, the corresponding starUSD is burned or removed from circulation.

Repayment takes starUSD from the borrower and reduces Trove debt.
Closing a Trove requires full repayment, including accrued interest, before collateral is released.
Redemptions reduce debt from the lowest-rate Troves and burn the redeemed starUSD.
Liquidations offset Trove debt using Stability Pool starUSD or sourced starUSD in the liquidation path.

Trustlines

starUSD is a Stellar issued asset. Users need a starUSD trustline before receiving newly minted starUSD. The frontend is expected to handle trustline onboarding and XLM reserve checks before transaction submission.

Backing Rule

Every starUSD minted by Lucent corresponds to protocol debt backed by collateral held by Lucent. The protocol should reject minting if the collateral ratio, oracle price, branch status, debt cap, receiver, or trustline checks fail.