Vault

The Vault operates as a smart contract 'bot' that is a user in the SDEX native vault, whose code can be found in the SdexVaultFacet. It exposes similar deposit/withdraw functionality as the TokenFarm on its own end, but on inside it is constantly reinvesting and accrued Sdex back into the platform to earn its patrons- the users, compounding rewards.Users deposit Sdex, and optionally apply an NFT. and the Vault begins by assessing its vSdex a synthetic balanceOf call for how much the vault currently has in its wallet. This is done as everything is under the diamondAddress. the amount deposited is converted into shares space the equation

$$shares_i = \frac{amount * \sum_{j=1}^n shares_j}{ bot_{sdex}}$$

Variable	Symbol	Description
shares to user	$shares_i$	The amount of shares one has of the Vault
deposited amount	amount	the amount just deposited by the user
total amount of Shares	$\sum_{j=1}^n shares_j$	the total amount of shares existing for the vault
Total amount of Sdex the bot owns	$bot_{sdex}$	the toal amount of Sdex the bot 'owns' (vSdex + amount currently staked in native pool)

This conversion is performed as the amount staked for a user is not constant, but compounds over time, what we do keep track of is the users proportion of assets relative to the whole.

A {VaultUserPosition} is created with its amount as its $shares_i$ and the tokenGlobal for the native Sdex pool is iterated to $shares_i$ * to handle rewards. The earn() function which instructs the bot to take any available Sdex it has and stake it into the Sdex Native farm using the enterStakingfunction AutoSdexFarmFacet, a middleware between the Vault and the Sdex TokenFarm. It is responsible for updating the {UserInfo} of the vault itself within the farm.

Withdraw also works similarily to the TokenFarmFacet. A NFT Reward is checked for, than if the stakeTime is passed. If not, penalization happens. In the even of a reward, two SDEX NFT's are minted, one that draws from the $stakeTime * amountStaked$ from the reward pool, and $(amountReturned - amountStaked) \times stakeTime$ for one that draws from the accrued Sdex Reward Pool.

The Vault also follows a lazy update architecture. The withdraw function does not restake the remaining tokens automatically, meaning some funds sit lying around not in the pool. Similar to Pancake swap as well, the harvest function enables users to earn a callFee for paying the gas to get the Vault to restake any left over tokens from withdraws.