YT Vault Module

Overview

YT module manages the configuration and lifecycle of "YT (Yield Token) products." It uses user deposits as collateral, borrows CBRToken through CBR, then generates fixed-rate liquidity positions through SLF (maturity recovery). Each YT instance is equipped with independent WalletInstance and YTHelper for executing specific strategies and fund operations. YTCore is responsible for creating/recording/maturing/liquidating YT instances and managing related permissions and statistics.

How YT Positions Work

When users open a YT position, the system follows these steps:

1. Deploy Position Wallet (Wallet Instance)

• Deploy a lightweight wallet contract specifically for this position to custody collateral and borrowed assets

2. Create Position in CBR

• Collateralize RWA assets

• Borrow SLB

• Create position and save CBR position ID in YT position information

3. Register Fixed Interest Lending Position in SLF

• Call static interest borrowing interface

• System calculates actual borrowable USDC based on SLB quantity

• Create SLF position with fixed maturity and save SLF position ID in YT position information

4. Transfer Assets to Wallet Instance

• User's RWA assets transfer to wallet

• Borrowed USDC (converted in SLF) transfers to wallet

5. Call YTHelper to Execute Strategy

• YTHelper converts USDC liquidity according to yield strategy

• Currently uses mint for direct conversion between assets (testing phase)

6. Risk Control Check & Position Recording

• Verify position meets safety requirements

• Record position in user's portfolio

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Functions and Responsibilities

1. Position Configuration Management

Allow protocol administrators to define and update position configurations:

• Deposit Token

• Borrow Token

• Position logic executor (YTHelper)

• Price oracle (Oracle)

• Maximum borrow rate (maxBorrowRate)

• Liquidation threshold (liquidationRate)

Bind configurations with corresponding deposit tokens for easy user strategy discovery.

2. Position Lifecycle Management

Create Position (createPosition):

• Initialize wallet instance (WalletInstance)

• Create loan in CBR, collateralize deposits and borrow CBRToken

• Convert CBRToken to liquidity, borrow target tokens in SLF

• Inject deposits and borrowed tokens into WalletInstance, execute initial investment logic through YTHelper

• Check position borrow rate reasonableness

Refresh Position Status (pokePosition):

• Call WalletInstance and SLF to update yield and debt data

Position Liquidation (liquidate):

• Liquidation must be executed by authorized liquidators when position LTV ≥ liquidationRate

• Liquidation transfers YTInstance ownership to liquidator

Position Maturity (matureYT):

• preMatureYT: At maturity or under admin/liquidator conditions, call YTHelper's prepareClose for closure preparation (e.g., converting LP positions back to base tokens). Must be triggered by owner or admin/liquidator (meeting preMatureAt conditions or being owner and liquidator)

• matureYT: At maturity or under authorized liquidation conditions, read current debt from SLF liquidityId (liquidityAmount + interestAmount), use YTHelper's close to complete strategy closure (convert assets back to corresponding tokens), then:

  • Authorize and call closeStatic to SLF (normal maturity closure of static position)

  • Authorize and call repay to CBR to repay corresponding CBR collateral (using collateralAmount in price lock)

  • Update totalYts (deduct settled debt amount), trigger PositionMatured event

• matureWithLiquidation: External parties (e.g., liquidators) first pay debt with borrowing tokens then close (closeStaticEarly), subsequently call helper's close, repay to CBR and update statistics. Suitable for "third-party debt payment and closure triggering" scenarios

3. Risk Control & Access Control

Position Rate Check:

• Use oracle prices to calculate position debt value / collateral value

• Exceeds maxBorrowRate → Block creation or operations

• Exceeds liquidationRate → Allow liquidator takeover

Liquidator Management:

• Protocol administrators can add/remove liquidators

• Only liquidators can execute position liquidations

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Interactions and Dependencies

CBR Module

• Used for collateral and lending logic (createLoan, repay)

• Manage collateral and borrowing token ledgers

SLF Module

• Responsible for fixed-rate liquidity positions and static borrowing

• Provide position debt data for maturity calculations

WalletInstance

• Independent wallet contract for each position, isolating position assets

• Execute position logic (investment, unstaking, reward claiming)

YTHelper

• Strategy execution logic specific to yield token strategies

• Called by YTCore to operate assets within WalletInstance

• Handles position closure and asset conversion at maturity

Oracle Interface

• Provide collateral and borrowing token prices

• Used to calculate position borrow rates and liquidation thresholds