> For the complete documentation index, see [llms.txt](https://cheomayield.gitbook.io/cheomayield-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cheomayield.gitbook.io/cheomayield-docs/contracts.md).

# Contracts

Source: `contracts/` in the CheomaYield repo.

## `CheomaPreDeposit.sol`

Fixed-APY tokenized vault. Non-transferable (soulbound) ERC-20 receipt.

**Immutables**

* `usdc` — deposit asset
* `apyBps` — fixed APY in basis points (e.g. 5200 = 52.00%)
* `admin` — config-only (cap + toggles)
* `treasury` — sole funds mover

**State**

* `cap` — max principal (`totalSupply`)
* `totalAssets`, `totalPrincipal`, `lastUpdate`

**Write**

* `deposit(uint256 amount)` — approve USDC first; mints receipt, records FIFO 90-day lot
* `redeem(uint256 shares)` — burn receipt → pro-rata USDC (requires lot maturity + `withdrawalsOpen`)
* `withdraw(uint256 amount, address to)` — `onlyTreasury`
* `setCap(uint256)`, `setDepositsOpen(bool)`, `setWithdrawalsOpen(bool)` — `onlyAdmin`
* `emergencyWithdrawAll(address to)` — `onlyTreasury`

**Read**

* `lotCount(address)`, `getLot(...)`, `firstUnconsumedLot(address)`

**Events**

* `Deposit(depositor, amount, shares, timestamp, maturity)`
* `Redeem(redeemer, shares, worth, timestamp)`
* `Withdrawal`, `CapUpdated`, `DepositsOpenUpdated`, `WithdrawalsOpenUpdated`, `EmergencyWithdrawAll`

## `PartnerPreDeposit.sol`

Bond-gated variant of `CheomaPreDeposit`.

**Immutables**

* `usdg` — deposit asset
* `partnerToken` — bond token (escrowed)
* `poolGiwaWeth`, `poolWethUsdg` — two-leg Uniswap V3 TWAP
* `apyBps`, `admin`, `treasury`

**Write**

* `deposit(uint256 amount)` — requires `partnerToken.balanceOf(msg.sender) >= minGateUsd`; escrows the bond
* `redeem(uint256 shares)` — bond released in-kind on full exit
* `setMinGateUsd(uint256)`, `setCap`, `setDepositsOpen`, `setWithdrawalsOpen` — `onlyAdmin`
* `forceReleaseBond(address user)` — `onlyTreasury`

**Events**

* `Deposit`, `Redeem`, `Withdrawal`, `BondPosted`, `BondReleased`, `PartnerGateUpdated`, `CapUpdated`, …

## `CheomaVault.sol`

Shares-based combined vault (testnet). Deposits mint internal shares; no transferable token; operator-managed yield.

## `CheomaReferralNFT.sol`

ERC-721 referral code NFT (10/90 entry/exit fee split on testnet). Note: **not** ERC-721 Enumerable — `tokenOfOwnerByIndex` is not implemented; per-wallet lookup must use `Transfer` logs.

## `CheomaFaucet.sol` / `MockUSDC.sol`

Testnet-only: free USDC faucet and open-mint mock stablecoin.


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