Dynamic Vault Program

Overview of Dynamic Yield Infrastructure

On-chain Program includes components

• Vault: to store native token. Vault always has a buffer, that user can withdraw at anytime

• Strategy Handler: submit liquidity in various lending protocols.

• Treasury: hold rewards and operation (performance) fee

How vault sync balances from various strategies:

Vault state:

pub struct Vault {
    /// The flag, if admin set enable = false, then the user can only withdraw and cannot deposit in the vault.
    pub enabled: u8,
    /// Vault nonce, to create vault seeds
    pub bumps: VaultBumps,
    /// The total liquidity of the vault, including remaining tokens in token_vault and the liquidity in all strategies.
    pub total_amount: u64,
    /// Token account, hold liquidity in vault reserve
    pub token_vault: Pubkey,
    /// Hold lp token of vault, each time rebalance crank is called, vault calculate performance fee and mint corresponding lp token amount to fee_vault. fee_vault is owned by treasury address
    pub fee_vault: Pubkey,
    /// Token mint that vault supports
    pub token_mint: Pubkey,
    /// Lp mint of vault
    pub lp_mint: Pubkey,
    /// The list of strategy addresses that vault supports, vault can support up to MAX_STRATEGY strategies at the same time.
    pub strategies: [Pubkey; MAX_STRATEGY],
    /// The base address to create vault seeds
    pub base: Pubkey,
    /// Admin of vault
    pub admin: Pubkey,
    /// Person who can send the crank. Operator can only send liquidity to strategies that admin defined, and claim reward to account of treasury address
    pub operator: Pubkey,
    /// Stores information for locked profit.
    pub locked_profit_tracker: LockedProfitTracker,
}

Strategy state:

pub struct Strategy {
    /// Lending pool address, that the strategy will deposit/withdraw balance
    pub reserve: Pubkey,
    /// The token account, that holds the collateral token
    pub collateral_vault: Pubkey,
    /// Specify type of strategy
    pub strategy_type: StrategyType,
    /// The liquidity in strategy at the time vault deposit/withdraw from a lending protocol
    pub current_liquidity: u64,
    /// Hold some bumps, in case the strategy needs to use other seeds to sign a CPI call.
    pub bumps: [u8; MAX_BUMPS],
    /// Vault address, that the strategy belongs
    pub vault: Pubkey,
}

In which total_amount denotes to vault liquidity. Buffer liquidity is stored in token_vault account. strategies stores all strategy pubkey, that vault integrate.

At any point of time, the following assertion must be satisfied:

vault.total_amount = token_vault.amount + sum(strategy.current_liquidity)

Which means total vault liquidity must be equal to buffer liquidity in vault and total liquidity in all strategies.

When keeper send rebalance crank in a strategy, program will update vault.total_amount and strategy.current_liquidity

// reload the new liquidity in this strategy
let new_liquidity = get_new_liquidity_in_this_strategy()

// sync balance in vault and this strategy
vault.total_amount = vault.total_amount + new_liqudity - strategy.current_liquidity;
strategy.current_liquidity = new_liquidity;