Token Lifecycle

StoneYield manages the full lifecycle of STUSD, its soul-bound hedge token. Each phase enforces security, transparency, and sustainable yield while avoiding speculative transfers.

1. Deposit and Generation

Participants initiate by authorizing protocol USDC transfers from their wallets. Following approval, the protocol generates equivalent STUSD (1:1) to the participant's address. This operation executes by the protocol owner (typically multisig) through the depositAndMint() function.

Key characteristics:

• STUSD generates with specified lock duration (minimum 1 hour, maximum 365 days)
• Lock enforces per-wallet via timestamp (unlockAt)
• Tokens maintain non-transferability while locked

2. Lock Duration

Upon generation, the participant's wallet receives time-lock, preventing token movement or approval until lock expiration. Lock durations remain participant-defined but bounded within permitted range. Following lock expiration, the participant must manually invoke unlock() to transition their address into fully transferable state.

3. Reward Allocation

The protocol periodically distributes yield through the rewardMint() function. This function generates additional STUSD tokens to selected participants. Newly generated rewards inherit lock status:

• If the participant maintains existing lock, new rewards follow current lock
• If the participant receives first reward, a 1-second placeholder lock applies to enforce manual unlock() step

4. Unlocking

Following lock period expiration, participants must explicitly invoke unlock() to designate their address as transferable. This introduces supplementary security layer and prevents accidental token transfers. Administrators may also execute emergency unlock utilizing adminUnlock() in exceptional cases.

5. Redemption

If premature exit becomes necessary, administrators may invoke earlyRedeem() to burn STUSD from a participant and return equivalent USDC amount. This process maintains strict owner-control and requires protocol to maintain sufficient USDC reserves.

6. Lifecycle Finalization

Following unlocking, participants can:

• Transfer STUSD (if protocol permits via isDex)
• Engage with whitelisted DEX or liquidity pools
• Burn STUSD via burn() for treasury or system operations

The lifecycle maintains on-chain tracking utilizing mappings like unlockAt, totalStaked, and hasStaked, enabling complete visibility into hedging history and lock status.